Faster RCNN 源码分析
Faster RCNN的python源码是由Ross Girshick写的，Ross Girshick真是神一样的存在，超级大牛。传统的DPM方法是他发明的，然后又一手开创了基于Proposal的深度学习Detection方法。就是我的偶像啊。下面详细分析Faster RCNN的源码，这份代码可以说包含了太多的编程技术，涉及了设计模式，封装，混编，并行等等，可以说如果能彻底看懂整个代码框架，那Python这门语言你就掌握了。我的感受就是有时候得去研究一个项目比本身学一门语言能学到更多东西。能让你研究透彻以后感到自己的能力提升了一个等级。Faster RCNN就是这样一个工程。而Caffe将是C++学习道路上的这个工程，需要笔者去翻越这座大山。
本文主要分析了整个项目代码的python部分，对应论文的算法，底层的CNN实现和优化由Caffe完成，这里暂时忽略。在一些重要的步骤，都会在后面添加注释。
言归正传，下面开始分析代码：
Faster RCNN的训练主程序是tools/train_faster_rcnn_alt_opt.py,这个程序需要结合Shell脚本传递参数，这里我直接在主程序里写死。
import _init_paths #将pycaffe和lib里面的model加入路径
from fast_rcnn.train import get_training_roidb, train_net
from fast_rcnn.config import cfg, cfg_from_file, cfg_from_list, get_output_dir
from datasets.factory import get_imdb
from rpn.generate import imdb_proposals
import datasets.imdb
import argparse
import pprint
import numpy as np
import sys, os
import multiprocessing as mp
import cPickle
import shutil
def parse_args():
"""
Parse input arguments
"""
parser = argparse.ArgumentParser(description='Train a Faster R-CNN network')
parser.add_argument('--gpu', dest='gpu_id',
help='GPU device id to use [0]',
default=0, type=int)
parser.add_argument('--net_name', dest='net_name',
help='network name (e.g., "ZF")',
default='VGG_CNN_M_1024', type=str)
parser.add_argument('--weights', dest='pretrained_model',
help='initialize with pretrained model weights',
default='/home/zou/py-faster-rcnn/data/imagenet_models/VGG_CNN_M_1024.v2.caffemodel', type=str)
parser.add_argument('--cfg', dest='cfg_file',
help='optional config file',
default='/home/zou/py-faster-rcnn/experiments/cfgs/faster_rcnn_alt_opt.yml', type=str)
parser.add_argument('--imdb', dest='imdb_name',
help='dataset to train on',
default='voc_2007_trainval', type=str)
parser.add_argument('--set', dest='set_cfgs',
help='set config keys', default=None,
nargs=argparse.REMAINDER)
args = parser.parse_args()
return args
def get_roidb(imdb_name, rpn_file=None):
imdb = get_imdb(imdb_name)#通过工厂类获取数据库信息
print 'Loaded dataset `{:s}` for training'.format(imdb.name)
imdb.set_proposal_method(cfg.TRAIN.PROPOSAL_METHOD)
print 'Set proposal method: {:s}'.format(cfg.TRAIN.PROPOSAL_METHOD)
if rpn_file is not None:
imdb.config['rpn_file'] = rpn_file
roidb = get_training_roidb(imdb)#获得训练数据
return roidb, imdb
def get_solvers(net_name):
# Faster R-CNN Alternating Optimization
n = 'faster_rcnn_alt_opt'
# Solver for each training stage
solvers = [[net_name, n, 'stage1_rpn_solver60k80k.pt'],
[net_name, n, 'stage1_fast_rcnn_solver30k40k.pt'],
[net_name, n, 'stage2_rpn_solver60k80k.pt'],
[net_name, n, 'stage2_fast_rcnn_solver30k40k.pt']]
solvers = [os.path.join(cfg.ROOT_DIR, 'models', *s) for s in solvers]
# Iterations for each training stage
#max_iters = [80000, 40000, 80000, 40000]
max_iters = [100, 100, 100, 100]
# Test prototxt for the RPN
rpn_test_prototxt = os.path.join(
cfg.ROOT_DIR, 'models', net_name, n, 'rpn_test.pt')
return solvers, max_iters, rpn_test_prototxt
# ------------------------------------------------------------------------------
# Pycaffe doesn't reliably free GPU memory when instantiated nets are discarded
# (e.g. "del net" in Python code). To work around this issue, each training
# stage is executed in a separate process using multiprocessing.Process.
# ------------------------------------------------------------------------------
def _init_caffe(cfg):#设置pycaffe的一些参数
"""Initialize pycaffe in a training process.
"""
import caffe
# fix the random seeds (numpy and caffe) for reproducibility
np.random.seed(cfg.RNG_SEED)
caffe.set_random_seed(cfg.RNG_SEED)
# set up caffe
caffe.set_mode_gpu()
caffe.set_device(cfg.GPU_ID)
def train_rpn(queue=None, imdb_name=None, init_model=None, solver=None,
max_iters=None, cfg=None):
"""Train a Region Proposal Network in a separate training process.
"""
# Not using any proposals, just ground-truth boxes
cfg.TRAIN.HAS_RPN = True
cfg.TRAIN.BBOX_REG = False # applies only to Fast R-CNN bbox regression
cfg.TRAIN.PROPOSAL_METHOD = 'gt'#用真值框来训练anchors
cfg.TRAIN.IMS_PER_BATCH = 1#每个batch一张图
print 'Init model: {}'.format(init_model)
print('Using config:')
pprint.pprint(cfg)
import caffe
_init_caffe(cfg)
roidb, imdb = get_roidb(imdb_name)#获取数据库信息
print 'roidb len: {}'.format(len(roidb))
output_dir = get_output_dir(imdb, None)
print 'Output will be saved to `{:s}`'.format(output_dir)
model_paths = train_net(solver, roidb, output_dir,
pretrained_model=init_model,
max_iters=max_iters)#定义模型参数
# Cleanup all but the final model
for i in model_paths[:-1]:
os.remove(i)
rpn_model_path = model_paths[-1]
# Send final model path through the multiprocessing queue
queue.put({'model_path': rpn_model_path})
def rpn_generate(queue=None, imdb_name=None, rpn_model_path=None, cfg=None,
rpn_test_prototxt=None):
"""Use a trained RPN to generate proposals.
"""
cfg.TEST.RPN_PRE_NMS_TOP_N = -1 # no pre NMS filtering
cfg.TEST.RPN_POST_NMS_TOP_N = 2000 # limit top boxes after NMS
print 'RPN model: {}'.format(rpn_model_path)
print('Using config:')
pprint.pprint(cfg)
import caffe
_init_caffe(cfg)
# NOTE: the matlab implementation computes proposals on flipped images, too.
# We compute them on the image once and then flip the already computed
# proposals. This might cause a minor loss in mAP (less proposal jittering).
imdb = get_imdb(imdb_name)
print 'Loaded dataset `{:s}` for proposal generation'.format(imdb.name)
# Load RPN and configure output directory
rpn_net = caffe.Net(rpn_test_prototxt, rpn_model_path, caffe.TEST)#用第一步生成的rpn模型生成rpns
output_dir = get_output_dir(imdb, None)
print 'Output will be saved to `{:s}`'.format(output_dir)
# Generate proposals on the imdb
rpn_proposals = imdb_proposals(rpn_net, imdb)#生成proposals
# Write proposals to disk and send the proposal file path through the
# multiprocessing queue
rpn_net_name = os.path.splitext(os.path.basename(rpn_model_path))[0]
rpn_proposals_path = os.path.join(
output_dir, rpn_net_name + '_proposals.pkl')
with open(rpn_proposals_path, 'wb') as f:
cPickle.dump(rpn_proposals, f, cPickle.HIGHEST_PROTOCOL)
print 'Wrote RPN proposals to {}'.format(rpn_proposals_path)
queue.put({'proposal_path': rpn_proposals_path})
def train_fast_rcnn(queue=None, imdb_name=None, init_model=None, solver=None,
max_iters=None, cfg=None, rpn_file=None):#这个过程就是标准的fast rcnn,只是原来的第三方生成的rois用rpn取代
"""Train a Fast R-CNN using proposals generated by an RPN.
"""
cfg.TRAIN.HAS_RPN = False # not generating prosals on-the-fly
cfg.TRAIN.PROPOSAL_METHOD = 'rpn' # use pre-computed RPN proposals instead
cfg.TRAIN.IMS_PER_BATCH = 2
print 'Init model: {}'.format(init_model)
print 'RPN proposals: {}'.format(rpn_file)
print('Using config:')
pprint.pprint(cfg)
import caffe
_init_caffe(cfg)
roidb, imdb = get_roidb(imdb_name, rpn_file=rpn_file)
output_dir = get_output_dir(imdb, None)
print 'Output will be saved to `{:s}`'.format(output_dir)
# Train Fast R-CNN
model_paths = train_net(solver, roidb, output_dir,
pretrained_model=init_model,
max_iters=max_iters)
# Cleanup all but the final model
for i in model_paths[:-1]:
os.remove(i)
fast_rcnn_model_path = model_paths[-1]
# Send Fast R-CNN model path over the multiprocessing queue
queue.put({'model_path': fast_rcnn_model_path})
if __name__ == '__main__':
args = parse_args() #从parse_args获取参数
print('Called with args:')
print(args)
if args.cfg_file is not None:
cfg_from_file(args.cfg_file)#将cfg的默认参数和cfg_file的修改参数合并
if args.set_cfgs is not None:
cfg_from_list(args.set_cfgs)
cfg.GPU_ID = args.gpu_id
# --------------------------------------------------------------------------
# Pycaffe doesn't reliably free GPU memory when instantiated nets are
# discarded (e.g. "del net" in Python code). To work around this issue, each
# training stage is executed in a separate process using
# multiprocessing.Process.
# --------------------------------------------------------------------------
# queue for communicated results between processes
mp_queue = mp.Queue()#并行处理
# solves, iters, etc. for each training stage
solvers, max_iters, rpn_test_prototxt = get_solvers(args.net_name)#获取solvers配置文件，最大训练次数，rpn_test的网络结构
print '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
print 'Stage 1 RPN, init from ImageNet model'
print '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
cfg.TRAIN.SNAPSHOT_INFIX = 'stage1'
mp_kwargs = dict(
queue=mp_queue,
imdb_name=args.imdb_name,
init_model=args.pretrained_model,
solver=solvers[0],
max_iters=max_iters[0],
cfg=cfg)
p = mp.Process(target=train_rpn, kwargs=mp_kwargs) #多线程运行
p.start()
rpn_stage1_out = mp_queue.get()
p.join()
print '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
print 'Stage 1 RPN, generate proposals'
print '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
mp_kwargs = dict(
queue=mp_queue,
imdb_name=args.imdb_name,
rpn_model_path=str(rpn_stage1_out['model_path']),
cfg=cfg,
rpn_test_prototxt=rpn_test_prototxt)
p = mp.Process(target=rpn_generate, kwargs=mp_kwargs)
p.start()
rpn_stage1_out['proposal_path'] = mp_queue.get()['proposal_path']
p.join()
print '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
print 'Stage 1 Fast R-CNN using RPN proposals, init from ImageNet model'
print '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
cfg.TRAIN.SNAPSHOT_INFIX = 'stage1'
mp_kwargs = dict(
queue=mp_queue,
imdb_name=args.imdb_name,
init_model=args.pretrained_model,
solver=solvers[1],
max_iters=max_iters[1],
cfg=cfg,
rpn_file=rpn_stage1_out['proposal_path'])
p = mp.Process(target=train_fast_rcnn, kwargs=mp_kwargs)
p.start()
fast_rcnn_stage1_out = mp_queue.get()
p.join()
print '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
print 'Stage 2 RPN, init from stage 1 Fast R-CNN model'
print '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
cfg.TRAIN.SNAPSHOT_INFIX = 'stage2'
mp_kwargs = dict(
queue=mp_queue,
imdb_name=args.imdb_name,
init_model=str(fast_rcnn_stage1_out['model_path']),
solver=solvers[2],
max_iters=max_iters[2],
cfg=cfg)
p = mp.Process(target=train_rpn, kwargs=mp_kwargs)
p.start()
rpn_stage2_out = mp_queue.get()
p.join()
print '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
print 'Stage 2 RPN, generate proposals'
print '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
mp_kwargs = dict(
queue=mp_queue,
imdb_name=args.imdb_name,
rpn_model_path=str(rpn_stage2_out['model_path']),
cfg=cfg,
rpn_test_prototxt=rpn_test_prototxt)
p = mp.Process(target=rpn_generate, kwargs=mp_kwargs)
p.start()
rpn_stage2_out['proposal_path'] = mp_queue.get()['proposal_path']
p.join()
print '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
print 'Stage 2 Fast R-CNN, init from stage 2 RPN R-CNN model'
print '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
cfg.TRAIN.SNAPSHOT_INFIX = 'stage2'
mp_kwargs = dict(
queue=mp_queue,
imdb_name=args.imdb_name,
init_model=str(rpn_stage2_out['model_path']),
solver=solvers[3],
max_iters=max_iters[3],
cfg=cfg,
rpn_file=rpn_stage2_out['proposal_path'])
p = mp.Process(target=train_fast_rcnn, kwargs=mp_kwargs)
p.start()
fast_rcnn_stage2_out = mp_queue.get()
p.join()
# Create final model (just a copy of the last stage)
final_path = os.path.join(
os.path.dirname(fast_rcnn_stage2_out['model_path']),
args.net_name + '_faster_rcnn_final.caffemodel')
print 'cp {} -> {}'.format(
fast_rcnn_stage2_out['model_path'], final_path)
shutil.copy(fast_rcnn_stage2_out['model_path'], final_path)
print 'Final model: {}'.format(final_path)
_init_paths.py将pycaffe和lib里面的model加入路径
import os.path as osp
import sys
def add_path(path):
if path not in sys.path:
sys.path.insert(0, path)
this_dir = osp.dirname(__file__)
# Add caffe to PYTHONPATH
caffe_path = osp.join(this_dir, '..', 'caffe-fast-rcnn', 'python')
add_path(caffe_path)
# Add lib to PYTHONPATH
lib_path = osp.join(this_dir, '..', 'lib')
add_path(lib_path)
========================================
下面一次是lib/dataset模块里的文件：
factory.py是工厂类，给定一个数据库名字生成一个数据库
__sets = {}
from datasets.pascal_voc import pascal_voc
import numpy as np
# Set up voc_<year>_<split> using selective search "fast" mode
for year in ['2007', '2012']:
for split in ['train', 'val', 'trainval', 'test']:
name = 'voc_{}_{}'.format(year, split)
__sets[name] = (lambda split=split, year=year: pascal_voc(split, year))# python的lambda函数，用于创建匿名函数，调用pascal_voc(split, year)
def get_imdb(name):
"""Get an imdb (image database) by name."""
if not __sets.has_key(name):
raise KeyError('Unknown dataset: {}'.format(name))
return __sets[name]()
def list_imdbs():
"""List all registered imdbs."""
return __sets.keys()
pascal_voc.py是数据库接口
import datasets
import datasets.pascal_voc
import os
import datasets.imdb
import xml.dom.minidom as minidom
import numpy as np
import scipy.sparse
import scipy.io as sio
import utils.cython_bbox
import cPickle
import subprocess
class pascal_voc(datasets.imdb):
def __init__(self, image_set, year, devkit_path=None):#对象初始化
datasets.imdb.__init__(self, 'voc_' + year + '_' + image_set)
self._year = year
self._image_set = image_set
self._devkit_path = self._get_default_path() if devkit_path is None \
else devkit_path
self._data_path = os.path.join(self._devkit_path, 'VOC' + self._year)
self._classes = ('__background__', # always index 0
'aeroplane', 'bicycle', 'bird', 'boat',
'bottle', 'bus', 'car', 'cat', 'chair',
'cow', 'diningtable', 'dog', 'horse',
'motorbike', 'person', 'pottedplant',
'sheep', 'sofa', 'train', 'tvmonitor')
self._class_to_ind = dict(zip(self.classes, xrange(self.num_classes)))
self._image_ext = '.jpg'
self._image_index = self._load_image_set_index()
# Default to roidb handler
self._roidb_handler = self.selective_search_roidb
# PASCAL specific config options
self.config = {'cleanup' : True,
'use_salt' : True,
'top_k' : 2000,
'use_diff' : False,
'rpn_file' : None}
assert os.path.exists(self._devkit_path), \
'VOCdevkit path does not exist: {}'.format(self._devkit_path)
assert os.path.exists(self._data_path), \
'Path does not exist: {}'.format(self._data_path)
def image_path_at(self, i):
"""
Return the absolute path to image i in the image sequence.
"""
return self.image_path_from_index(self._image_index[i])
def image_path_from_index(self, index):
"""
Construct an image path from the image's "index" identifier.
"""
image_path = os.path.join(self._data_path, 'JPEGImages',
index + self._image_ext)
assert os.path.exists(image_path), \
'Path does not exist: {}'.format(image_path)
return image_path
def _load_image_set_index(self):#获取数据库图片的名称
"""
Load the indexes listed in this dataset's image set file.
"""
# Example path to image set file:
# self._devkit_path + /VOCdevkit2007/VOC2007/ImageSets/Main/val.txt
image_set_file = os.path.join(self._data_path, 'ImageSets', 'Main',
self._image_set + '.txt')
assert os.path.exists(image_set_file), \
'Path does not exist: {}'.format(image_set_file)
with open(image_set_file) as f:
image_index = [x.strip() for x in f.readlines()]
return image_index
def _get_default_path(self):#返回数据的存储路径
"""
Return the default path where PASCAL VOC is expected to be installed.
"""
return os.path.join(datasets.ROOT_DIR, 'data', 'VOCdevkit' + self._year)
def gt_roidb(self):#这里会调用一个修饰器来调用直接一次性调用这个函数，所以调试的过程中会出现不同步的诡异现象
"""
Return the database of ground-truth regions of interest.
This function loads/saves from/to a cache file to speed up future calls.
"""
cache_file = os.path.join(self.cache_path, self.name + '_gt_roidb.pkl')#如果cache里有数据则读取那里面的数据如果不存在则读取列表存储的index
if os.path.exists(cache_file):
with open(cache_file, 'rb') as fid:
roidb = cPickle.load(fid)
print '{} gt roidb loaded from {}'.format(self.name, cache_file)
return roidb
gt_roidb = [self._load_pascal_annotation(index)#获取数据rois
for index in self.image_index]
with open(cache_file, 'wb') as fid:#写入cache
cPickle.dump(gt_roidb, fid, cPickle.HIGHEST_PROTOCOL)
print 'wrote gt roidb to {}'.format(cache_file)
return gt_roidb
def selective_search_roidb(self):
"""
Return the database of selective search regions of interest.
Ground-truth ROIs are also included.
This function loads/saves from/to a cache file to speed up future calls.
"""
cache_file = os.path.join(self.cache_path,
self.name + '_selective_search_roidb.pkl')
if os.path.exists(cache_file):
with open(cache_file, 'rb') as fid:
roidb = cPickle.load(fid)
print '{} ss roidb loaded from {}'.format(self.name, cache_file)
return roidb
if int(self._year) == 2007 or self._image_set != 'test':
gt_roidb = self.gt_roidb()
ss_roidb = self._load_selective_search_roidb(gt_roidb)
roidb = datasets.imdb.merge_roidbs(gt_roidb, ss_roidb)
else:
roidb = self._load_selective_search_roidb(None)
with open(cache_file, 'wb') as fid:
cPickle.dump(roidb, fid, cPickle.HIGHEST_PROTOCOL)
print 'wrote ss roidb to {}'.format(cache_file)
return roidb
def rpn_roidb(self):#在fast rcnn调用数据库时候使用
if int(self._year) == 2007 or self._image_set != 'test':
gt_roidb = self.gt_roidb()
rpn_roidb = self._load_rpn_roidb(gt_roidb)
roidb = datasets.imdb.merge_roidbs(gt_roidb, rpn_roidb)
else:
roidb = self._load_rpn_roidb(None)
return roidb
def _load_rpn_roidb(self, gt_roidb):
filename = self.config['rpn_file']
print 'loading {}'.format(filename)
assert os.path.exists(filename), \
'rpn data not found at: {}'.format(filename)
with open(filename, 'rb') as f:
box_list = cPickle.load(f)
return self.create_roidb_from_box_list(box_list, gt_roidb)
def _load_selective_search_roidb(self, gt_roidb):
filename = os.path.abspath(os.path.join(self.cache_path, '..',
'selective_search_data',
self.name + '.mat'))
assert os.path.exists(filename), \
'Selective search data not found at: {}'.format(filename)
raw_data = sio.loadmat(filename)['boxes'].ravel()
box_list = []
for i in xrange(raw_data.shape[0]):
box_list.append(raw_data[i][:, (1, 0, 3, 2)] - 1)
return self.create_roidb_from_box_list(box_list, gt_roidb)
def _load_pascal_annotation(self, index):
"""
Load image and bounding boxes info from XML file in the PASCAL VOC
format.
"""
filename = os.path.join(self._data_path, 'Annotations', index + '.xml')#获取对应的xml标签，
# print 'Loading: {}'.format(filename)
def get_data_from_tag(node, tag):
return node.getElementsByTagName(tag)[0].childNodes[0].data
with open(filename) as f:
data = minidom.parseString(f.read())#xml读取接口
objs = data.getElementsByTagName('object')
if not self.config['use_diff']:
# Exclude the samples labeled as difficult
non_diff_objs = [obj for obj in objs
if int(get_data_from_tag(obj, 'difficult')) == 0]
if len(non_diff_objs) != len(objs):
print 'Removed {} difficult objects' \
.format(len(objs) - len(non_diff_objs))
objs = non_diff_objs
num_objs = len(objs)#获取去除difficult标记的object个数
boxes = np.zeros((num_objs, 4), dtype=np.uint16)#初始化Box
gt_classes = np.zeros((num_objs), dtype=np.int32)#初始化标签
overlaps = np.zeros((num_objs, self.num_classes), dtype=np.float32)#初始化覆盖率
# Load object bounding boxes into a data frame.
for ix, obj in enumerate(objs):
# Make pixel indexes 0-based
x1 = float(get_data_from_tag(obj, 'xmin')) - 1
y1 = float(get_data_from_tag(obj, 'ymin')) - 1
x2 = float(get_data_from_tag(obj, 'xmax')) - 1
y2 = float(get_data_from_tag(obj, 'ymax')) - 1#获取坐标-1，默认坐标从0开始
cls = self._class_to_ind[
str(get_data_from_tag(obj, "name")).lower().strip()]
boxes[ix, :] = [x1, y1, x2, y2]#将坐标填入对应位置
gt_classes[ix] = cls#将类别填入对应位置
overlaps[ix, cls] = 1.0#将覆盖率填入对应位置，真值框覆盖率为1
overlaps = scipy.sparse.csr_matrix(overlaps)#用稀疏矩阵表示
return {'boxes' : boxes,
'gt_classes': gt_classes,
'gt_overlaps' : overlaps,
'flipped' : False}
def _write_voc_results_file(self, all_boxes):
use_salt = self.config['use_salt']
comp_id = 'comp4'
if use_salt:
comp_id += '-{}'.format(os.getpid())
# VOCdevkit/results/VOC2007/Main/comp4-44503_det_test_aeroplane.txt
path = os.path.join(self._devkit_path, 'results', 'VOC' + self._year,
'Main', comp_id + '_')
for cls_ind, cls in enumerate(self.classes):
if cls == '__background__':
continue
print 'Writing {} VOC results file'.format(cls)
filename = path + 'det_' + self._image_set + '_' + cls + '.txt'
with open(filename, 'wt') as f:
for im_ind, index in enumerate(self.image_index):
dets = all_boxes[cls_ind][im_ind]
if dets == []:
continue
# the VOCdevkit expects 1-based indices
for k in xrange(dets.shape[0]):
f.write('{:s} {:.3f} {:.1f} {:.1f} {:.1f} {:.1f}\n'.
format(index, dets[k, -1],
dets[k, 0] + 1, dets[k, 1] + 1,
dets[k, 2] + 1, dets[k, 3] + 1))
return comp_id
def _do_matlab_eval(self, comp_id, output_dir='output'):
rm_results = self.config['cleanup']
path = os.path.join(os.path.dirname(__file__),
'VOCdevkit-matlab-wrapper')
cmd = 'cd {} && '.format(path)
cmd += '{:s} -nodisplay -nodesktop '.format(datasets.MATLAB)
cmd += '-r "dbstop if error; '
cmd += 'voc_eval(\'{:s}\',\'{:s}\',\'{:s}\',\'{:s}\',{:d}); quit;"' \
.format(self._devkit_path, comp_id,
self._image_set, output_dir, int(rm_results))
print('Running:\n{}'.format(cmd))
status = subprocess.call(cmd, shell=True)
def evaluate_detections(self, all_boxes, output_dir):
comp_id = self._write_voc_results_file(all_boxes)
self._do_matlab_eval(comp_id, output_dir)
def competition_mode(self, on):
if on:
self.config['use_salt'] = False
self.config['cleanup'] = False
else:
self.config['use_salt'] = True
self.config['cleanup'] = True
if __name__ == '__main__':
d = datasets.pascal_voc('trainval', '2007')
res = d.roidb
from IPython import embed; embed()
imdb.py是数据库文件
import os
import os.path as osp
import PIL
from utils.cython_bbox import bbox_overlaps
import numpy as np
import scipy.sparse
import datasets
class imdb(object):
"""Image database."""
def __init__(self, name):
self._name = name
self._num_classes = 0
self._classes = []
self._image_index = []
self._obj_proposer = 'selective_search'
self._roidb = None
self._roidb_handler = self.default_roidb
# Use this dict for storing dataset specific config options
self.config = {}
@property
def name(self):
return self._name
@property
def num_classes(self):
return len(self._classes)
@property
def classes(self):
return self._classes
@property
def image_index(self):
return self._image_index
@property
def roidb_handler(self):
return self._roidb_handler
@roidb_handler.setter
def roidb_handler(self, val):
self._roidb_handler = val
def set_proposal_method(self, method):
method = eval('self.' + method + '_roidb')#eval函数把字符串当成表达式求值
self.roidb_handler = method#通过调用pascal_voc.py的gt_roidb
@property
def roidb(self):
# A roidb is a list of dictionaries, each with the following keys:
# boxes
# gt_overlaps
# gt_classes
# flipped
if self._roidb is not None:
return self._roidb
self._roidb = self.roidb_handler()
return self._roidb
@property
def cache_path(self):
cache_path = osp.abspath(osp.join(datasets.ROOT_DIR, 'data', 'cache'))
if not os.path.exists(cache_path):
os.makedirs(cache_path)
return cache_path
@property
def num_images(self):
return len(self.image_index)
def image_path_at(self, i):
raise NotImplementedError
def default_roidb(self):
raise NotImplementedError
def evaluate_detections(self, all_boxes, output_dir=None):
"""
all_boxes is a list of length number-of-classes.
Each list element is a list of length number-of-images.
Each of those list elements is either an empty list []
or a numpy array of detection.
all_boxes[class][image] = [] or np.array of shape #dets x 5
"""
raise NotImplementedError
def append_flipped_images(self):#左右镜像翻转数据，用flipped的true和false标记
num_images = self.num_images
widths = [PIL.Image.open(self.image_path_at(i)).size[0]
for i in xrange(num_images)]
for i in xrange(num_images):
boxes = self.roidb[i]['boxes'].copy()
oldx1 = boxes[:, 0].copy()
oldx2 = boxes[:, 2].copy()
boxes[:, 0] = widths[i] - oldx2 - 1
boxes[:, 2] = widths[i] - oldx1 - 1
assert (boxes[:, 2] >= boxes[:, 0]).all()
entry = {'boxes' : boxes,
'gt_overlaps' : self.roidb[i]['gt_overlaps'],
'gt_classes' : self.roidb[i]['gt_classes'],
'flipped' : True}
self.roidb.append(entry)
self._image_index = self._image_index * 2
def evaluate_recall(self, candidate_boxes=None, ar_thresh=0.5):
# Record max overlap value for each gt box
# Return vector of overlap values
gt_overlaps = np.zeros(0)
for i in xrange(self.num_images):
gt_inds = np.where(self.roidb[i]['gt_classes'] > 0)[0]
gt_boxes = self.roidb[i]['boxes'][gt_inds, :]
if candidate_boxes is None:
non_gt_inds = np.where(self.roidb[i]['gt_classes'] == 0)[0]
boxes = self.roidb[i]['boxes'][non_gt_inds, :]
else:
boxes = candidate_boxes[i]
if boxes.shape[0] == 0:
continue
overlaps = bbox_overlaps(boxes.astype(np.float),
gt_boxes.astype(np.float))
# gt_overlaps = np.hstack((gt_overlaps, overlaps.max(axis=0)))
_gt_overlaps = np.zeros((gt_boxes.shape[0]))
for j in xrange(gt_boxes.shape[0]):
argmax_overlaps = overlaps.argmax(axis=0)
max_overlaps = overlaps.max(axis=0)
gt_ind = max_overlaps.argmax()
gt_ovr = max_overlaps.max()
assert(gt_ovr >= 0)
box_ind = argmax_overlaps[gt_ind]
_gt_overlaps[j] = overlaps[box_ind, gt_ind]
assert(_gt_overlaps[j] == gt_ovr)
overlaps[box_ind, :] = -1
overlaps[:, gt_ind] = -1
gt_overlaps = np.hstack((gt_overlaps, _gt_overlaps))
num_pos = gt_overlaps.size
gt_overlaps = np.sort(gt_overlaps)
step = 0.001
thresholds = np.minimum(np.arange(0.5, 1.0 + step, step), 1.0)
recalls = np.zeros_like(thresholds)
for i, t in enumerate(thresholds):
recalls[i] = (gt_overlaps >= t).sum() / float(num_pos)
ar = 2 * np.trapz(recalls, thresholds)
return ar, gt_overlaps, recalls, thresholds
def create_roidb_from_box_list(self, box_list, gt_roidb):
assert len(box_list) == self.num_images, \
'Number of boxes must match number of ground-truth images'
roidb = []
for i in xrange(self.num_images):
boxes = box_list[i]
num_boxes = boxes.shape[0]
overlaps = np.zeros((num_boxes, self.num_classes), dtype=np.float32)
if gt_roidb is not None:
gt_boxes = gt_roidb[i]['boxes']
gt_classes = gt_roidb[i]['gt_classes']
gt_overlaps = bbox_overlaps(boxes.astype(np.float),
gt_boxes.astype(np.float))
argmaxes = gt_overlaps.argmax(axis=1)
maxes = gt_overlaps.max(axis=1)
I = np.where(maxes > 0)[0]
overlaps[I, gt_classes[argmaxes[I]]] = maxes[I]
overlaps = scipy.sparse.csr_matrix(overlaps)
roidb.append({'boxes' : boxes,
'gt_classes' : np.zeros((num_boxes,),
dtype=np.int32),
'gt_overlaps' : overlaps,
'flipped' : False})
return roidb
@staticmethod
def merge_roidbs(a, b):
assert len(a) == len(b)
for i in xrange(len(a)):
a[i]['boxes'] = np.vstack((a[i]['boxes'], b[i]['boxes']))
a[i]['gt_classes'] = np.hstack((a[i]['gt_classes'],
b[i]['gt_classes']))
a[i]['gt_overlaps'] = scipy.sparse.vstack([a[i]['gt_overlaps'],
b[i]['gt_overlaps']])
return a
def competition_mode(self, on):
"""Turn competition mode on or off."""
pass
init.py是该模块必要文件
from .imdb import imdb
from . import factory
import os.path as osp
ROOT_DIR = osp.join(osp.dirname(__file__), '..', '..')
# We assume your matlab binary is in your path and called `matlab'.
# If either is not true, just add it to your path and alias it as matlab, or
# you could change this file.
MATLAB = 'matlab'
# http://stackoverflow.com/questions/377017/test-if-executable-exists-in-python
def _which(program):
import os
def is_exe(fpath):
return os.path.isfile(fpath) and os.access(fpath, os.X_OK)
fpath, fname = os.path.split(program)
if fpath:
if is_exe(program):
return program
else:
for path in os.environ["PATH"].split(os.pathsep):
path = path.strip('"')
exe_file = os.path.join(path, program)
if is_exe(exe_file):
return exe_file
return None
if _which(MATLAB) is None:
msg = ("MATLAB command '{}' not found. "
"Please add '{}' to your PATH.").format(MATLAB, MATLAB)
raise EnvironmentError(msg)
========================================
下面一次是lib/fast_rcnn模块里的文件：
train.py
# --------------------------------------------------------
# Fast R-CNN
# Copyright (c) 2015 Microsoft
# Licensed under The MIT License [see LICENSE for details]
# Written by Ross Girshick
# --------------------------------------------------------
"""Train a Fast R-CNN network."""
import caffe
from fast_rcnn.config import cfg
import roi_data_layer.roidb as rdl_roidb
from utils.timer import Timer
import numpy as np
import os
from caffe.proto import caffe_pb2
import google.protobuf as pb2
class SolverWrapper(object):
"""A simple wrapper around Caffe's solver.
This wrapper gives us control over he snapshotting process, which we
use to unnormalize the learned bounding-box regression weights.
"""
def __init__(self, solver_prototxt, roidb, output_dir,
pretrained_model=None):
"""Initialize the SolverWrapper."""
self.output_dir = output_dir
if (cfg.TRAIN.HAS_RPN and cfg.TRAIN.BBOX_REG and
cfg.TRAIN.BBOX_NORMALIZE_TARGETS):
# RPN can only use precomputed normalization because there are no
# fixed statistics to compute a priori
assert cfg.TRAIN.BBOX_NORMALIZE_TARGETS_PRECOMPUTED
if cfg.TRAIN.BBOX_REG:
print 'Computing bounding-box regression targets...'
self.bbox_means, self.bbox_stds = \
rdl_roidb.add_bbox_regression_targets(roidb)
print 'done'
self.solver = caffe.SGDSolver(solver_prototxt)#pycaffe接口，根据配置文件逐层初始化网络
if pretrained_model is not None:
print ('Loading pretrained model '
'weights from {:s}').format(pretrained_model)
self.solver.net.copy_from(pretrained_model)#从预训练模型载入参数
self.solver_param = caffe_pb2.SolverParameter()
with open(solver_prototxt, 'rt') as f:
pb2.text_format.Merge(f.read(), self.solver_param)#获取solver参数
self.solver.net.layers[0].set_roidb(roidb)#输入rois
def snapshot(self):
"""Take a snapshot of the network after unnormalizing the learned
bounding-box regression weights. This enables easy use at test-time.
"""
net = self.solver.net
scale_bbox_params = (cfg.TRAIN.BBOX_REG and
cfg.TRAIN.BBOX_NORMALIZE_TARGETS and
net.params.has_key('bbox_pred'))
if scale_bbox_params:
# save original values
orig_0 = net.params['bbox_pred'][0].data.copy()
orig_1 = net.params['bbox_pred'][1].data.copy()
# scale and shift with bbox reg unnormalization; then save snapshot
net.params['bbox_pred'][0].data[...] = \
(net.params['bbox_pred'][0].data *
self.bbox_stds[:, np.newaxis])
net.params['bbox_pred'][1].data[...] = \
(net.params['bbox_pred'][1].data *
self.bbox_stds + self.bbox_means)
if not os.path.exists(self.output_dir):
os.makedirs(self.output_dir)
infix = ('_' + cfg.TRAIN.SNAPSHOT_INFIX
if cfg.TRAIN.SNAPSHOT_INFIX != '' else '')
filename = (self.solver_param.snapshot_prefix + infix +
'_iter_{:d}'.format(self.solver.iter) + '.caffemodel')
filename = os.path.join(self.output_dir, filename)
net.save(str(filename))
print 'Wrote snapshot to: {:s}'.format(filename)
if scale_bbox_params:
# restore net to original state
net.params['bbox_pred'][0].data[...] = orig_0
net.params['bbox_pred'][1].data[...] = orig_1
return filename
def train_model(self, max_iters):
"""Network training loop."""
last_snapshot_iter = -1
timer = Timer()
model_paths = []
while self.solver.iter < max_iters:
# Make one SGD update
timer.tic()
self.solver.step(1)#每过一次训练，每个python层都能进入，C++层则无法进入
timer.toc()
if self.solver.iter % (10 * self.solver_param.display) == 0:
print 'speed: {:.3f}s / iter'.format(timer.average_time)
if self.solver.iter % cfg.TRAIN.SNAPSHOT_ITERS == 0:
last_snapshot_iter = self.solver.iter
model_paths.append(self.snapshot())
if last_snapshot_iter != self.solver.iter:
model_paths.append(self.snapshot())
return model_paths
def get_training_roidb(imdb): #产生用于训练的数据，数据镜像翻转增加1倍
"""Returns a roidb (Region of Interest database) for use in training."""
if cfg.TRAIN.USE_FLIPPED:#在训练rpn时候roi为gt，在训练fast-rcnn时候roi为rpn框+gt
print 'Appending horizontally-flipped training examples...'
imdb.append_flipped_images()
print 'done'
print 'Preparing training data...'
rdl_roidb.prepare_roidb(imdb)
print 'done'
return imdb.roidb
def train_net(solver_prototxt, roidb, output_dir,
pretrained_model=None, max_iters=40000):
"""Train a Fast R-CNN network."""
sw = SolverWrapper(solver_prototxt, roidb, output_dir,
pretrained_model=pretrained_model)#定义模型的接口
print 'Solving...'
model_paths = sw.train_model(max_iters)#训练模型
print 'done solving'
return model_paths
test.py
"""Test a Fast R-CNN network on an imdb (image database)."""
from fast_rcnn.config import cfg, get_output_dir
from fast_rcnn.bbox_transform import clip_boxes, bbox_transform_inv
import argparse
from utils.timer import Timer
import numpy as np
import cv2
import caffe
from fast_rcnn.nms_wrapper import nms
import cPickle
import heapq
from utils.blob import im_list_to_blob
import os
def _get_image_blob(im):
"""Converts an image into a network input.
Arguments:
im (ndarray): a color image in BGR order
Returns:
blob (ndarray): a data blob holding an image pyramid
im_scale_factors (list): list of image scales (relative to im) used
in the image pyramid
"""
im_orig = im.astype(np.float32, copy=True)
im_orig -= cfg.PIXEL_MEANS
im_shape = im_orig.shape
im_size_min = np.min(im_shape[0:2])
im_size_max = np.max(im_shape[0:2])
processed_ims = []
im_scale_factors = []
for target_size in cfg.TEST.SCALES:
im_scale = float(target_size) / float(im_size_min)
# Prevent the biggest axis from being more than MAX_SIZE
if np.round(im_scale * im_size_max) > cfg.TEST.MAX_SIZE:
im_scale = float(cfg.TEST.MAX_SIZE) / float(im_size_max)
im = cv2.resize(im_orig, None, None, fx=im_scale, fy=im_scale,
interpolation=cv2.INTER_LINEAR)
im_scale_factors.append(im_scale)
processed_ims.append(im)
# Create a blob to hold the input images
blob = im_list_to_blob(processed_ims)
return blob, np.array(im_scale_factors)
def _get_rois_blob(im_rois, im_scale_factors):
"""Converts RoIs into network inputs.
Arguments:
im_rois (ndarray): R x 4 matrix of RoIs in original image coordinates
im_scale_factors (list): scale factors as returned by _get_image_blob
Returns:
blob (ndarray): R x 5 matrix of RoIs in the image pyramid
"""
rois, levels = _project_im_rois(im_rois, im_scale_factors)
rois_blob = np.hstack((levels, rois))
return rois_blob.astype(np.float32, copy=False)
def _project_im_rois(im_rois, scales):
"""Project image RoIs into the image pyramid built by _get_image_blob.
Arguments:
im_rois (ndarray): R x 4 matrix of RoIs in original image coordinates
scales (list): scale factors as returned by _get_image_blob
Returns:
rois (ndarray): R x 4 matrix of projected RoI coordinates
levels (list): image pyramid levels used by each projected RoI
"""
im_rois = im_rois.astype(np.float, copy=False)
if len(scales) > 1:
widths = im_rois[:, 2] - im_rois[:, 0] + 1
heights = im_rois[:, 3] - im_rois[:, 1] + 1
areas = widths * heights
scaled_areas = areas[:, np.newaxis] * (scales[np.newaxis, :] ** 2)
diff_areas = np.abs(scaled_areas - 224 * 224)
levels = diff_areas.argmin(axis=1)[:, np.newaxis]
else:
levels = np.zeros((im_rois.shape[0], 1), dtype=np.int)
rois = im_rois * scales[levels]
return rois, levels
def _get_blobs(im, rois):
"""Convert an image and RoIs within that image into network inputs."""
blobs = {'data' : None, 'rois' : None}
blobs['data'], im_scale_factors = _get_image_blob(im)
if not cfg.TEST.HAS_RPN:
blobs['rois'] = _get_rois_blob(rois, im_scale_factors)
return blobs, im_scale_factors
def im_detect(net, im, boxes=None):
"""Detect object classes in an image given object proposals.
Arguments:
net (caffe.Net): Fast R-CNN network to use
im (ndarray): color image to test (in BGR order)
boxes (ndarray): R x 4 array of object proposals or None (for RPN)
Returns:
scores (ndarray): R x K array of object class scores (K includes
background as object category 0)
boxes (ndarray): R x (4*K) array of predicted bounding boxes
"""
blobs, im_scales = _get_blobs(im, boxes)
# When mapping from image ROIs to feature map ROIs, there's some aliasing
# (some distinct image ROIs get mapped to the same feature ROI).
# Here, we identify duplicate feature ROIs, so we only compute features
# on the unique subset.
if cfg.DEDUP_BOXES > 0 and not cfg.TEST.HAS_RPN:
v = np.array([1, 1e3, 1e6, 1e9, 1e12])
hashes = np.round(blobs['rois'] * cfg.DEDUP_BOXES).dot(v)
_, index, inv_index = np.unique(hashes, return_index=True,
return_inverse=True)
blobs['rois'] = blobs['rois'][index, :]
boxes = boxes[index, :]
if cfg.TEST.HAS_RPN:
im_blob = blobs['data']
blobs['im_info'] = np.array(
[[im_blob.shape[2], im_blob.shape[3], im_scales[0]]],
dtype=np.float32)
# reshape network inputs
net.blobs['data'].reshape(*(blobs['data'].shape))
if cfg.TEST.HAS_RPN:
net.blobs['im_info'].reshape(*(blobs['im_info'].shape))
else:
net.blobs['rois'].reshape(*(blobs['rois'].shape))
# do forward
forward_kwargs = {'data': blobs['data'].astype(np.float32, copy=False)}
if cfg.TEST.HAS_RPN:
forward_kwargs['im_info'] = blobs['im_info'].astype(np.float32, copy=False)
else:
forward_kwargs['rois'] = blobs['rois'].astype(np.float32, copy=False)
blobs_out = net.forward(**forward_kwargs)
if cfg.TEST.HAS_RPN:
assert len(im_scales) == 1, "Only single-image batch implemented"
rois = net.blobs['rois'].data.copy()
# unscale back to raw image space
boxes = rois[:, 1:5] / im_scales[0]
if cfg.TEST.SVM:
# use the raw scores before softmax under the assumption they
# were trained as linear SVMs
scores = net.blobs['cls_score'].data
else:
# use softmax estimated probabilities
scores = blobs_out['cls_prob']
if cfg.TEST.BBOX_REG:
# Apply bounding-box regression deltas
box_deltas = blobs_out['bbox_pred']
pred_boxes = bbox_transform_inv(boxes, box_deltas)
pred_boxes = clip_boxes(pred_boxes, im.shape)
else:
# Simply repeat the boxes, once for each class
pred_boxes = np.tile(boxes, (1, scores.shape[1]))
if cfg.DEDUP_BOXES > 0 and not cfg.TEST.HAS_RPN:
# Map scores and predictions back to the original set of boxes
scores = scores[inv_index, :]
pred_boxes = pred_boxes[inv_index, :]
return scores, pred_boxes
def vis_detections(im, class_name, dets, thresh=0.3):
"""Visual debugging of detections."""
import matplotlib.pyplot as plt
im = im[:, :, (2, 1, 0)]
for i in xrange(np.minimum(10, dets.shape[0])):
bbox = dets[i, :4]
score = dets[i, -1]
if score > thresh:
plt.cla()
plt.imshow(im)
plt.gca().add_patch(
plt.Rectangle((bbox[0], bbox[1]),
bbox[2] - bbox[0],
bbox[3] - bbox[1], fill=False,
edgecolor='g', linewidth=3)
)
plt.title('{} {:.3f}'.format(class_name, score))
plt.show()
def apply_nms(all_boxes, thresh):
"""Apply non-maximum suppression to all predicted boxes output by the
test_net method.
"""
num_classes = len(all_boxes)
num_images = len(all_boxes[0])
nms_boxes = [[[] for _ in xrange(num_images)]
for _ in xrange(num_classes)]
for cls_ind in xrange(num_classes):
for im_ind in xrange(num_images):
dets = all_boxes[cls_ind][im_ind]
if dets == []:
continue
keep = nms(dets, thresh)
if len(keep) == 0:
continue
nms_boxes[cls_ind][im_ind] = dets[keep, :].copy()
return nms_boxes
def test_net(net, imdb):
"""Test a Fast R-CNN network on an image database."""
num_images = len(imdb.image_index)
# heuristic: keep an average of 40 detections per class per images prior
# to NMS
max_per_set = 40 * num_images
# heuristic: keep at most 100 detection per class per image prior to NMS
max_per_image = 100
# detection thresold for each class (this is adaptively set based on the
# max_per_set constraint)
thresh = -np.inf * np.ones(imdb.num_classes)
# top_scores will hold one minheap of scores per class (used to enforce
# the max_per_set constraint)
top_scores = [[] for _ in xrange(imdb.num_classes)]
# all detections are collected into:
# all_boxes[cls][image] = N x 5 array of detections in
# (x1, y1, x2, y2, score)
all_boxes = [[[] for _ in xrange(num_images)]
for _ in xrange(imdb.num_classes)]
output_dir = get_output_dir(imdb, net)
if not os.path.exists(output_dir):
os.makedirs(output_dir)
# timers
_t = {'im_detect' : Timer(), 'misc' : Timer()}
if not cfg.TEST.HAS_RPN:
roidb = imdb.roidb
for i in xrange(num_images):
# filter out any ground truth boxes
if cfg.TEST.HAS_RPN:
box_proposals = None
else:
box_proposals = roidb[i]['boxes'][roidb[i]['gt_classes'] == 0]
im = cv2.imread(imdb.image_path_at(i))
_t['im_detect'].tic()
scores, boxes = im_detect(net, im, box_proposals)
_t['im_detect'].toc()
_t['misc'].tic()
for j in xrange(1, imdb.num_classes):
inds = np.where(scores[:, j] > thresh[j])[0]
cls_scores = scores[inds, j]
cls_boxes = boxes[inds, j*4:(j+1)*4]
top_inds = np.argsort(-cls_scores)[:max_per_image]
cls_scores = cls_scores[top_inds]
cls_boxes = cls_boxes[top_inds, :]
# push new scores onto the minheap
for val in cls_scores:
heapq.heappush(top_scores[j], val)
# if we've collected more than the max number of detection,
# then pop items off the minheap and update the class threshold
if len(top_scores[j]) > max_per_set:
while len(top_scores[j]) > max_per_set:
heapq.heappop(top_scores[j])
thresh[j] = top_scores[j][0]
all_boxes[j][i] = \
np.hstack((cls_boxes, cls_scores[:, np.newaxis])) \
.astype(np.float32, copy=False)
if 0:
keep = nms(all_boxes[j][i], 0.3)
vis_detections(im, imdb.classes[j], all_boxes[j][i][keep, :])
_t['misc'].toc()
print 'im_detect: {:d}/{:d} {:.3f}s {:.3f}s' \
.format(i + 1, num_images, _t['im_detect'].average_time,
_t['misc'].average_time)
for j in xrange(1, imdb.num_classes):
for i in xrange(num_images):
inds = np.where(all_boxes[j][i][:, -1] > thresh[j])[0]
all_boxes[j][i] = all_boxes[j][i][inds, :]
det_file = os.path.join(output_dir, 'detections.pkl')
with open(det_file, 'wb') as f:
cPickle.dump(all_boxes, f, cPickle.HIGHEST_PROTOCOL)
print 'Applying NMS to all detections'
nms_dets = apply_nms(all_boxes, cfg.TEST.NMS)
print 'Evaluating detections'
imdb.evaluate_detections(nms_dets, output_dir)
config.py
# --------------------------------------------------------
# Fast R-CNN
# Copyright (c) 2015 Microsoft
# Licensed under The MIT License [see LICENSE for details]
# Written by Ross Girshick
# --------------------------------------------------------
"""Fast R-CNN config system.
This file specifies default config options for Fast R-CNN. You should not
change values in this file. Instead, you should write a config file (in yaml)
and use cfg_from_file(yaml_file) to load it and override the default options.
Most tools in $ROOT/tools take a --cfg option to specify an override file.
- See tools/{train,test}_net.py for example code that uses cfg_from_file()
- See experiments/cfgs/*.yml for example YAML config override files
"""
import os
import os.path as osp
import numpy as np
# `pip install easydict` if you don't have it
from easydict import EasyDict as edict
__C = edict()
# Consumers can get config by:
# from fast_rcnn_config import cfg
cfg = __C
#
# Training options
#
__C.TRAIN = edict()
# Scales to use during training (can list multiple scales)
# Each scale is the pixel size of an image's shortest side
__C.TRAIN.SCALES = (960,)
# Max pixel size of the longest side of a scaled input image
__C.TRAIN.MAX_SIZE = 1280
# Images to use per minibatch
__C.TRAIN.IMS_PER_BATCH = 2
# Minibatch size (number of regions of interest [ROIs])
__C.TRAIN.BATCH_SIZE = 128
# Fraction of minibatch that is labeled foreground (i.e. class > 0)
__C.TRAIN.FG_FRACTION = 0.25
# Overlap threshold for a ROI to be considered foreground (if >= FG_THRESH)
__C.TRAIN.FG_THRESH = 0.5
# Overlap threshold for a ROI to be considered background (class = 0 if
# overlap in [LO, HI))
__C.TRAIN.BG_THRESH_HI = 0.5
__C.TRAIN.BG_THRESH_LO = 0.1
# Use horizontally-flipped images during training?
__C.TRAIN.USE_FLIPPED = True
# Train bounding-box regressors
__C.TRAIN.BBOX_REG = True
# Overlap required between a ROI and ground-truth box in order for that ROI to
# be used as a bounding-box regression training example
__C.TRAIN.BBOX_THRESH = 0.5
# Iterations between snapshots
__C.TRAIN.SNAPSHOT_ITERS = 10000
# solver.prototxt specifies the snapshot path prefix, this adds an optional
# infix to yield the path: <prefix>[_<infix>]_iters_XYZ.caffemodel
__C.TRAIN.SNAPSHOT_INFIX = ''
# Use a prefetch thread in roi_data_layer.layer
# So far I haven't found this useful; likely more engineering work is required
__C.TRAIN.USE_PREFETCH = False
# Normalize the targets (subtract empirical mean, divide by empirical stddev)
__C.TRAIN.BBOX_NORMALIZE_TARGETS = True
# Deprecated (inside weights)
__C.TRAIN.BBOX_INSIDE_WEIGHTS = (1.0, 1.0, 1.0, 1.0)
# Normalize the targets using "precomputed" (or made up) means and stdevs
# (BBOX_NORMALIZE_TARGETS must also be True)
__C.TRAIN.BBOX_NORMALIZE_TARGETS_PRECOMPUTED = False
__C.TRAIN.BBOX_NORMALIZE_MEANS = (0.0, 0.0, 0.0, 0.0)
__C.TRAIN.BBOX_NORMALIZE_STDS = (0.1, 0.1, 0.2, 0.2)
# Train using these proposals
__C.TRAIN.PROPOSAL_METHOD = 'selective_search'
# Make minibatches from images that have similar aspect ratios (i.e. both
# tall and thin or both short and wide) in order to avoid wasting computation
# on zero-padding.
__C.TRAIN.ASPECT_GROUPING = True
# Use RPN to detect objects
__C.TRAIN.HAS_RPN = False
# IOU >= thresh: positive example
__C.TRAIN.RPN_POSITIVE_OVERLAP = 0.7
# IOU < thresh: negative example
__C.TRAIN.RPN_NEGATIVE_OVERLAP = 0.3
# If an anchor statisfied by positive and negative conditions set to negative
__C.TRAIN.RPN_CLOBBER_POSITIVES = False
# Max number of foreground examples
__C.TRAIN.RPN_FG_FRACTION = 0.5
# Total number of examples
__C.TRAIN.RPN_BATCHSIZE = 256
# NMS threshold used on RPN proposals
__C.TRAIN.RPN_NMS_THRESH = 0.7
# Number of top scoring boxes to keep before apply NMS to RPN proposals
__C.TRAIN.RPN_PRE_NMS_TOP_N = 12000
# Number of top scoring boxes to keep after applying NMS to RPN proposals
__C.TRAIN.RPN_POST_NMS_TOP_N = 2000
# Proposal height and width both need to be greater than RPN_MIN_SIZE (at orig image scale)
__C.TRAIN.RPN_MIN_SIZE = 15
# Deprecated (outside weights)
__C.TRAIN.RPN_BBOX_INSIDE_WEIGHTS = (1.0, 1.0, 1.0, 1.0)
# Give the positive RPN examples weight of p * 1 / {num positives}
# and give negatives a weight of (1 - p)
# Set to -1.0 to use uniform example weighting
__C.TRAIN.RPN_POSITIVE_WEIGHT = -1.0
#
# Testing options
#
__C.TEST = edict()
# Scales to use during testing (can list multiple scales)
# Each scale is the pixel size of an image's shortest side
__C.TEST.SCALES = (960,)
# Max pixel size of the longest side of a scaled input image
__C.TEST.MAX_SIZE = 1280
# Overlap threshold used for non-maximum suppression (suppress boxes with
# IoU >= this threshold)
__C.TEST.NMS = 0.3
# Experimental: treat the (K+1) units in the cls_score layer as linear
# predictors (trained, eg, with one-vs-rest SVMs).
__C.TEST.SVM = False
# Test using bounding-box regressors
__C.TEST.BBOX_REG = True
# Propose boxes
__C.TEST.HAS_RPN = False
# Test using these proposals
__C.TEST.PROPOSAL_METHOD = 'selective_search'
## NMS threshold used on RPN proposals
__C.TEST.RPN_NMS_THRESH = 0.7
## Number of top scoring boxes to keep before apply NMS to RPN proposals
__C.TEST.RPN_PRE_NMS_TOP_N = 12000
## Number of top scoring boxes to keep after applying NMS to RPN proposals
__C.TEST.RPN_POST_NMS_TOP_N = 1000
# Proposal height and width both need to be greater than RPN_MIN_SIZE (at orig image scale)
__C.TEST.RPN_MIN_SIZE = 15
#
# MISC
#
# The mapping from image coordinates to feature map coordinates might cause
# some boxes that are distinct in image space to become identical in feature
# coordinates. If DEDUP_BOXES > 0, then DEDUP_BOXES is used as the scale factor
# for identifying duplicate boxes.
# 1/16 is correct for {Alex,Caffe}Net, VGG_CNN_M_1024, and VGG16
__C.DEDUP_BOXES = 1./16.
# Pixel mean values (BGR order) as a (1, 1, 3) array
# These are the values originally used for training VGG16
__C.PIXEL_MEANS = np.array([[[102.9801, 115.9465, 122.7717]]])
# For reproducibility
__C.RNG_SEED = 3
# A small number that's used many times
__C.EPS = 1e-14
# Root directory of project
__C.ROOT_DIR = osp.abspath(osp.join(osp.dirname(__file__), '..', '..'))
# Place outputs under an experiments directory
__C.EXP_DIR = 'default'
# Use GPU implementation of non-maximum suppression
__C.USE_GPU_NMS = True
# Default GPU device id
__C.GPU_ID = 0
def get_output_dir(imdb, net):
"""Return the directory where experimental artifacts are placed.
A canonical path is built using the name from an imdb and a network
(if not None).
"""
path = osp.abspath(osp.join(__C.ROOT_DIR, 'output', __C.EXP_DIR, imdb.name))
if net is None:
return path
else:
return osp.join(path, net.name)
def _merge_a_into_b(a, b):
"""Merge config dictionary a into config dictionary b, clobbering the
options in b whenever they are also specified in a.
"""
if type(a) is not edict:
return
for k, v in a.iteritems():
# a must specify keys that are in b
if not b.has_key(k):
raise KeyError('{} is not a valid config key'.format(k))
# the types must match, too
old_type = type(b[k])
if old_type is not type(v):
if isinstance(b[k], np.ndarray):
v = np.array(v, dtype=b[k].dtype)
else:
raise ValueError(('Type mismatch ({} vs. {}) '
'for config key: {}').format(type(b[k]),
type(v), k))
# recursively merge dicts
if type(v) is edict:
try:
_merge_a_into_b(a[k], b[k])
except:
print('Error under config key: {}'.format(k))
raise
else:
b[k] = v
def cfg_from_file(filename):
"""Load a config file and merge it into the default options."""
import yaml
with open(filename, 'r') as f:
yaml_cfg = edict(yaml.load(f))
_merge_a_into_b(yaml_cfg, __C)
def cfg_from_list(cfg_list):
"""Set config keys via list (e.g., from command line)."""
from ast import literal_eval
assert len(cfg_list) % 2 == 0
for k, v in zip(cfg_list[0::2], cfg_list[1::2]):
key_list = k.split('.')
d = __C
for subkey in key_list[:-1]:
assert d.has_key(subkey)
d = d[subkey]
subkey = key_list[-1]
assert d.has_key(subkey)
try:
value = literal_eval(v)
except:
# handle the case when v is a string literal
value = v
assert type(value) == type(d[subkey]), \
'type {} does not match original type {}'.format(
type(value), type(d[subkey]))
d[subkey] = value
bbox_transform.py主要计算box regression的变化和恢复
import numpy as np
def bbox_transform(ex_rois, gt_rois):
ex_widths = ex_rois[:, 2] - ex_rois[:, 0] + 1.0#width
ex_heights = ex_rois[:, 3] - ex_rois[:, 1] + 1.0#height
ex_ctr_x = ex_rois[:, 0] + 0.5 * ex_widths#x_center
ex_ctr_y = ex_rois[:, 1] + 0.5 * ex_heights#y_center
gt_widths = gt_rois[:, 2] - gt_rois[:, 0] + 1.0#gt_width
gt_heights = gt_rois[:, 3] - gt_rois[:, 1] + 1.0#gt_height
gt_ctr_x = gt_rois[:, 0] + 0.5 * gt_widths#gt_x_cebter
gt_ctr_y = gt_rois[:, 1] + 0.5 * gt_heights#gt_y_center
targets_dx = (gt_ctr_x - ex_ctr_x) / ex_widths#dx=(gt_cx-anchor_cx)/anchor_w
targets_dy = (gt_ctr_y - ex_ctr_y) / ex_heights#dy=(gt_cy-anchor_cy)/anchor_h
targets_dw = np.log(gt_widths / ex_widths)#log(gt_w/anchor_w)
targets_dh = np.log(gt_heights / ex_heights)#log(gt_h/anchor_h)
targets = np.vstack(
(targets_dx, targets_dy, targets_dw, targets_dh)).transpose()
return targets
def bbox_transform_inv(boxes, deltas):#上一个函数的逆运算，由delta值和对应的anchor计算出box坐标
if boxes.shape[0] == 0:
return np.zeros((0, deltas.shape[1]), dtype=deltas.dtype)
boxes = boxes.astype(deltas.dtype, copy=False)
widths = boxes[:, 2] - boxes[:, 0] + 1.0#anchor_w
heights = boxes[:, 3] - boxes[:, 1] + 1.0#anchor_h
ctr_x = boxes[:, 0] + 0.5 * widths#anchor_cx
ctr_y = boxes[:, 1] + 0.5 * heights#anchor_cy
dx = deltas[:, 0::4]
dy = deltas[:, 1::4]
dw = deltas[:, 2::4]
dh = deltas[:, 3::4]
pred_ctr_x = dx * widths[:, np.newaxis] + ctr_x[:, np.newaxis]#dx*anchor_w+anchor_cx
pred_ctr_y = dy * heights[:, np.newaxis] + ctr_y[:, np.newaxis]#dy*abchor_h+anchor_cy
pred_w = np.exp(dw) * widths[:, np.newaxis]#exp(dw)*anchor_w
pred_h = np.exp(dh) * heights[:, np.newaxis]#exp(dh)*anchor_h
pred_boxes = np.zeros(deltas.shape, dtype=deltas.dtype)#下面是由预测框的中心和长宽还原成左上右下坐标
# x1
pred_boxes[:, 0::4] = pred_ctr_x - 0.5 * pred_w
# y1
pred_boxes[:, 1::4] = pred_ctr_y - 0.5 * pred_h
# x2
pred_boxes[:, 2::4] = pred_ctr_x + 0.5 * pred_w
# y2
pred_boxes[:, 3::4] = pred_ctr_y + 0.5 * pred_h
return pred_boxes
def clip_boxes(boxes, im_shape):
"""
Clip boxes to image boundaries.
"""
# x1 >= 0
boxes[:, 0::4] = np.maximum(np.minimum(boxes[:, 0::4], im_shape[1] - 1), 0)
# y1 >= 0
boxes[:, 1::4] = np.maximum(np.minimum(boxes[:, 1::4], im_shape[0] - 1), 0)
# x2 < im_shape[1]
boxes[:, 2::4] = np.maximum(np.minimum(boxes[:, 2::4], im_shape[1] - 1), 0)
# y2 < im_shape[0]
boxes[:, 3::4] = np.maximum(np.minimum(boxes[:, 3::4], im_shape[0] - 1), 0)
return boxes
nums_wrapper.py
from fast_rcnn.config import cfg
from nms.gpu_nms import gpu_nms
from nms.cpu_nms import cpu_nms
def nms(dets, thresh):
"""Dispatch to either CPU or GPU NMS implementations."""
if dets.shape[0] == 0:
return []
if cfg.USE_GPU_NMS:
return gpu_nms(dets, thresh, device_id=cfg.GPU_ID)
else:
return cpu_nms(dets, thresh)
========================================
下面一次是lib/roi_data_layer模块里的文件：
roidb.py
import numpy as np
from fast_rcnn.config import cfg
from fast_rcnn.bbox_transform import bbox_transform
from utils.cython_bbox import bbox_overlaps
import PIL
def prepare_roidb(imdb):#为ROI数据添加部分熟悉，同时检查数据
"""Enrich the imdb's roidb by adding some derived quantities that
are useful for training. This function precomputes the maximum
overlap, taken over ground-truth boxes, between each ROI and
each ground-truth box. The class with maximum overlap is also
recorded.
"""
sizes = [PIL.Image.open(imdb.image_path_at(i)).size
for i in xrange(imdb.num_images)]
roidb = imdb.roidb
for i in xrange(len(imdb.image_index)):
roidb[i]['image'] = imdb.image_path_at(i)
roidb[i]['width'] = sizes[i][0]
roidb[i]['height'] = sizes[i][1]
# need gt_overlaps as a dense array for argmax
gt_overlaps = roidb[i]['gt_overlaps'].toarray()
# max overlap with gt over classes (columns)
max_overlaps = gt_overlaps.max(axis=1)
# gt class that had the max overlap
max_classes = gt_overlaps.argmax(axis=1)
roidb[i]['max_classes'] = max_classes
roidb[i]['max_overlaps'] = max_overlaps
# sanity checks
# max overlap of 0 => class should be zero (background)
zero_inds = np.where(max_overlaps == 0)[0]
assert all(max_classes[zero_inds] == 0)
# max overlap > 0 => class should not be zero (must be a fg class)
nonzero_inds = np.where(max_overlaps > 0)[0]
assert all(max_classes[nonzero_inds] != 0)
def add_bbox_regression_targets(roidb):#用来计算训练box regressor的信息
"""Add information needed to train bounding-box regressors."""
assert len(roidb) > 0
assert 'max_classes' in roidb[0], 'Did you call prepare_roidb first?'
num_images = len(roidb)
# Infer number of classes from the number of columns in gt_overlaps
num_classes = roidb[0]['gt_overlaps'].shape[1]
for im_i in xrange(num_images):
rois = roidb[im_i]['boxes']
max_overlaps = roidb[im_i]['max_overlaps']
max_classes = roidb[im_i]['max_classes']
roidb[im_i]['bbox_targets'] = \
_compute_targets(rois, max_overlaps, max_classes)
if cfg.TRAIN.BBOX_NORMALIZE_TARGETS_PRECOMPUTED:
# Use fixed / precomputed "means" and "stds" instead of empirical values
means = np.tile(
np.array(cfg.TRAIN.BBOX_NORMALIZE_MEANS), (num_classes, 1))
stds = np.tile(
np.array(cfg.TRAIN.BBOX_NORMALIZE_STDS), (num_classes, 1))
else:#统计每个类别的box target的均值和方差，作归一化，在预测时候将结果乘上方差再加上均值，这样做的好处可能是为了训练归一化的同一类别框，使得预测同一类别的坐标框不会有很大的差异性。
# Compute values needed for means and stds
# var(x) = E(x^2) - E(x)^2
class_counts = np.zeros((num_classes, 1)) + cfg.EPS
sums = np.zeros((num_classes, 4))
squared_sums = np.zeros((num_classes, 4))
for im_i in xrange(num_images):
targets = roidb[im_i]['bbox_targets']
for cls in xrange(1, num_classes):
cls_inds = np.where(targets[:, 0] == cls)[0]
if cls_inds.size > 0:
class_counts[cls] += cls_inds.size
sums[cls, :] += targets[cls_inds, 1:].sum(axis=0)
squared_sums[cls, :] += \
(targets[cls_inds, 1:] ** 2).sum(axis=0)
means = sums / class_counts
stds = np.sqrt(squared_sums / class_counts - means ** 2)
print 'bbox target means:'
print means
print means[1:, :].mean(axis=0) # ignore bg class
print 'bbox target stdevs:'
print stds
print stds[1:, :].mean(axis=0) # ignore bg class
# Normalize targets
if cfg.TRAIN.BBOX_NORMALIZE_TARGETS:
print "Normalizing targets"
for im_i in xrange(num_images):
targets = roidb[im_i]['bbox_targets']
for cls in xrange(1, num_classes):
cls_inds = np.where(targets[:, 0] == cls)[0]
roidb[im_i]['bbox_targets'][cls_inds, 1:] -= means[cls, :]
roidb[im_i]['bbox_targets'][cls_inds, 1:] /= stds[cls, :]
else:
print "NOT normalizing targets"
# These values will be needed for making predictions
# (the predicts will need to be unnormalized and uncentered)
return means.ravel(), stds.ravel()
def _compute_targets(rois, overlaps, labels):
"""Compute bounding-box regression targets for an image."""
# Indices of ground-truth ROIs
gt_inds = np.where(overlaps == 1)[0]#找到真值框
# Indices of examples for which we try to make predictions
ex_inds = np.where(overlaps >= cfg.TRAIN.BBOX_THRESH)[0]#覆盖率大于阈值的rois
# Get IoU overlap between each ex ROI and gt ROI
ex_gt_overlaps = bbox_overlaps(
np.ascontiguousarray(rois[ex_inds, :], dtype=np.float),
np.ascontiguousarray(rois[gt_inds, :], dtype=np.float))#计算大于阈值的rois和真值的覆盖率
# Find which gt ROI each ex ROI has max overlap with:
# this will be the ex ROI's gt target
gt_assignment = ex_gt_overlaps.argmax(axis=1)
gt_rois = rois[gt_inds[gt_assignment], :]
ex_rois = rois[ex_inds, :]
targets = np.zeros((rois.shape[0], 5), dtype=np.float32)
targets[ex_inds, 0] = labels[ex_inds]
targets[ex_inds, 1:] = bbox_transform(ex_rois, gt_rois)
return targets
layer.py定义了ROIDataLayer
import caffe
from fast_rcnn.config import cfg
from roi_data_layer.minibatch import get_minibatch
import numpy as np
import yaml
from multiprocessing import Process, Queue
class RoIDataLayer(caffe.Layer):
"""Fast R-CNN data layer used for training."""
def _shuffle_roidb_inds(self):
"""Randomly permute the training roidb."""
if cfg.TRAIN.ASPECT_GROUPING:
widths = np.array([r['width'] for r in self._roidb])
heights = np.array([r['height'] for r in self._roidb])
horz = (widths >= heights)
vert = np.logical_not(horz)
horz_inds = np.where(horz)[0]
vert_inds = np.where(vert)[0]
inds = np.hstack((
np.random.permutation(horz_inds),
np.random.permutation(vert_inds)))
inds = np.reshape(inds, (-1, 2))
row_perm = np.random.permutation(np.arange(inds.shape[0]))
inds = np.reshape(inds[row_perm, :], (-1,))
self._perm = inds
else:
self._perm = np.random.permutation(np.arange(len(self._roidb)))
self._cur = 0
def _get_next_minibatch_inds(self):
"""Return the roidb indices for the next minibatch."""
if self._cur + cfg.TRAIN.IMS_PER_BATCH >= len(self._roidb):
self._shuffle_roidb_inds()
db_inds = self._perm[self._cur:self._cur + cfg.TRAIN.IMS_PER_BATCH]
self._cur += cfg.TRAIN.IMS_PER_BATCH
return db_inds
def _get_next_minibatch(self):
"""Return the blobs to be used for the next minibatch.
If cfg.TRAIN.USE_PREFETCH is True, then blobs will be computed in a
separate process and made available through self._blob_queue.
"""
if cfg.TRAIN.USE_PREFETCH:
return self._blob_queue.get()
else:
db_inds = self._get_next_minibatch_inds()
minibatch_db = [self._roidb[i] for i in db_inds]
return get_minibatch(minibatch_db, self._num_classes)
def set_roidb(self, roidb):
"""Set the roidb to be used by this layer during training."""
self._roidb = roidb
self._shuffle_roidb_inds()
if cfg.TRAIN.USE_PREFETCH:
self._blob_queue = Queue(10)
self._prefetch_process = BlobFetcher(self._blob_queue,
self._roidb,
self._num_classes)
self._prefetch_process.start()
# Terminate the child process when the parent exists
def cleanup():
print 'Terminating BlobFetcher'
self._prefetch_process.terminate()
self._prefetch_process.join()
import atexit
atexit.register(cleanup)
def setup(self, bottom, top):# Setup the RoIDataLayer,只在初始化网络时候调用，定义top的id和所需参数
"""Setup the RoIDataLayer."""
# parse the layer parameter string, which must be valid YAML
layer_params = yaml.load(self.param_str_)
self._num_classes = layer_params['num_classes']
self._name_to_top_map = {}
# data blob: holds a batch of N images, each with 3 channels
idx = 0
top[idx].reshape(cfg.TRAIN.IMS_PER_BATCH, 3,
max(cfg.TRAIN.SCALES), cfg.TRAIN.MAX_SIZE)
self._name_to_top_map['data'] = idx
idx += 1
if cfg.TRAIN.HAS_RPN:
top[idx].reshape(1, 3)
self._name_to_top_map['im_info'] = idx
idx += 1
top[idx].reshape(1, 4)
self._name_to_top_map['gt_boxes'] = idx
idx += 1
else: # not using RPN
# rois blob: holds R regions of interest, each is a 5-tuple
# (n, x1, y1, x2, y2) specifying an image batch index n and a
# rectangle (x1, y1, x2, y2)
top[idx].reshape(1, 5)
self._name_to_top_map['rois'] = idx
idx += 1
# labels blob: R categorical labels in [0, ..., K] for K foreground
# classes plus background
top[idx].reshape(1)
self._name_to_top_map['labels'] = idx
idx += 1
if cfg.TRAIN.BBOX_REG:
# bbox_targets blob: R bounding-box regression targets with 4
# targets per class
top[idx].reshape(1, self._num_classes * 4)
self._name_to_top_map['bbox_targets'] = idx
idx += 1
# bbox_inside_weights blob: At most 4 targets per roi are active;
# thisbinary vector sepcifies the subset of active targets
top[idx].reshape(1, self._num_classes * 4)
self._name_to_top_map['bbox_inside_weights'] = idx
idx += 1
top[idx].reshape(1, self._num_classes * 4)
self._name_to_top_map['bbox_outside_weights'] = idx
idx += 1
print 'RoiDataLayer: name_to_top:', self._name_to_top_map
assert len(top) == len(self._name_to_top_map)
def forward(self, bottom, top):#随机获取一个blobs然后根据序号分别输出top
"""Get blobs and copy them into this layer's top blob vector."""
blobs = self._get_next_minibatch()#获得第一次需要的top数据
for blob_name, blob in blobs.iteritems():
top_ind = self._name_to_top_map[blob_name]
# Reshape net's input blobs
top[top_ind].reshape(*(blob.shape))
# Copy data into net's input blobs
top[top_ind].data[...] = blob.astype(np.float32, copy=False)
def backward(self, top, propagate_down, bottom):
"""This layer does not propagate gradients."""
pass
def reshape(self, bottom, top):#初始化层和前向传播的时候reshape大小，根据需要确定是否需要
"""Reshaping happens during the call to forward."""
pass
class BlobFetcher(Process):
"""Experimental class for prefetching blobs in a separate process."""
def __init__(self, queue, roidb, num_classes):
super(BlobFetcher, self).__init__()
self._queue = queue
self._roidb = roidb
self._num_classes = num_classes
self._perm = None
self._cur = 0
self._shuffle_roidb_inds()
# fix the random seed for reproducibility
np.random.seed(cfg.RNG_SEED)
def _shuffle_roidb_inds(self):
"""Randomly permute the training roidb."""
# TODO(rbg): remove duplicated code
self._perm = np.random.permutation(np.arange(len(self._roidb)))
self._cur = 0
def _get_next_minibatch_inds(self):
"""Return the roidb indices for the next minibatch."""
# TODO(rbg): remove duplicated code
if self._cur + cfg.TRAIN.IMS_PER_BATCH >= len(self._roidb):
self._shuffle_roidb_inds()
db_inds = self._perm[self._cur:self._cur + cfg.TRAIN.IMS_PER_BATCH]
self._cur += cfg.TRAIN.IMS_PER_BATCH
return db_inds
def run(self):
print 'BlobFetcher started'
while True:
db_inds = self._get_next_minibatch_inds()
minibatch_db = [self._roidb[i] for i in db_inds]
blobs = get_minibatch(minibatch_db, self._num_classes)
self._queue.put(blobs)
minibatch.py
"""Compute minibatch blobs for training a Fast R-CNN network."""
import numpy as np
import numpy.random as npr
import cv2
from fast_rcnn.config import cfg
from utils.blob import prep_im_for_blob, im_list_to_blob
def get_minibatch(roidb, num_classes):#在这里将获得的一个数据随机resize成参数里设置的大小
"""Given a roidb, construct a minibatch sampled from it."""
num_images = len(roidb)
# Sample random scales to use for each image in this batch
random_scale_inds = npr.randint(0, high=len(cfg.TRAIN.SCALES),
size=num_images)
assert(cfg.TRAIN.BATCH_SIZE % num_images == 0), \
'num_images ({}) must divide BATCH_SIZE ({})'. \
format(num_images, cfg.TRAIN.BATCH_SIZE)
rois_per_image = cfg.TRAIN.BATCH_SIZE / num_images
fg_rois_per_image = np.round(cfg.TRAIN.FG_FRACTION * rois_per_image)
# Get the input image blob, formatted for caffe
im_blob, im_scales = _get_image_blob(roidb, random_scale_inds)
blobs = {'data': im_blob}
if cfg.TRAIN.HAS_RPN:
assert len(im_scales) == 1, "Single batch only"
assert len(roidb) == 1, "Single batch only"
# gt boxes: (x1, y1, x2, y2, cls)
gt_inds = np.where(roidb[0]['gt_classes'] != 0)[0]
gt_boxes = np.empty((len(gt_inds), 5), dtype=np.float32)
gt_boxes[:, 0:4] = roidb[0]['boxes'][gt_inds, :] * im_scales[0]
gt_boxes[:, 4] = roidb[0]['gt_classes'][gt_inds]
blobs['gt_boxes'] = gt_boxes
blobs['im_info'] = np.array(
[[im_blob.shape[2], im_blob.shape[3], im_scales[0]]],
dtype=np.float32)
else: # not using RPN，这里输出了fast rcnn阶段需要的tops
# Now, build the region of interest and label blobs
rois_blob = np.zeros((0, 5), dtype=np.float32)
labels_blob = np.zeros((0), dtype=np.float32)
bbox_targets_blob = np.zeros((0, 4 * num_classes), dtype=np.float32)
bbox_inside_blob = np.zeros(bbox_targets_blob.shape, dtype=np.float32)
# all_overlaps = []
for im_i in xrange(num_images):
labels, overlaps, im_rois, bbox_targets, bbox_inside_weights \
= _sample_rois(roidb[im_i], fg_rois_per_image, rois_per_image,
num_classes)
# Add to RoIs blob
rois = _project_im_rois(im_rois, im_scales[im_i])
batch_ind = im_i * np.ones((rois.shape[0], 1))
rois_blob_this_image = np.hstack((batch_ind, rois))
rois_blob = np.vstack((rois_blob, rois_blob_this_image))
# Add to labels, bbox targets, and bbox loss blobs
labels_blob = np.hstack((labels_blob, labels))
bbox_targets_blob = np.vstack((bbox_targets_blob, bbox_targets))
bbox_inside_blob = np.vstack((bbox_inside_blob, bbox_inside_weights))
# all_overlaps = np.hstack((all_overlaps, overlaps))
# For debug visualizations
# _vis_minibatch(im_blob, rois_blob, labels_blob, all_overlaps)
blobs['rois'] = rois_blob
blobs['labels'] = labels_blob
if cfg.TRAIN.BBOX_REG:
blobs['bbox_targets'] = bbox_targets_blob
blobs['bbox_inside_weights'] = bbox_inside_blob
blobs['bbox_outside_weights'] = \
np.array(bbox_inside_blob > 0).astype(np.float32)
return blobs #输出需要的top blobs
def _sample_rois(roidb, fg_rois_per_image, rois_per_image, num_classes):
"""Generate a random sample of RoIs comprising foreground and background
examples.
"""
# label = class RoI has max overlap with
labels = roidb['max_classes']#ROI的max_classes
overlaps = roidb['max_overlaps']#ROI的overlaps
rois = roidb['boxes']#ROI坐标
# Select foreground RoIs as those with >= FG_THRESH overlap
fg_inds = np.where(overlaps >= cfg.TRAIN.FG_THRESH)[0]#大于阈值的为前景，并随机选择指定数量的fg
# Guard against the case when an image has fewer than fg_rois_per_image
# foreground RoIs
fg_rois_per_this_image = np.minimum(fg_rois_per_image, fg_inds.size)
# Sample foreground regions without replacement
if fg_inds.size > 0:
fg_inds = npr.choice(
fg_inds, size=fg_rois_per_this_image, replace=False)
# Select background RoIs as those within [BG_THRESH_LO, BG_THRESH_HI)
bg_inds = np.where((overlaps < cfg.TRAIN.BG_THRESH_HI) &
(overlaps >= cfg.TRAIN.BG_THRESH_LO))[0]#选择在指定阈值之内的rois为背景类并随机选择指定数量的bg
# Compute number of background RoIs to take from this image (guarding
# against there being fewer than desired)
bg_rois_per_this_image = rois_per_image - fg_rois_per_this_image
bg_rois_per_this_image = np.minimum(bg_rois_per_this_image,
bg_inds.size)
# Sample foreground regions without replacement
if bg_inds.size > 0:
bg_inds = npr.choice(
bg_inds, size=bg_rois_per_this_image, replace=False)
# The indices that we're selecting (both fg and bg)
keep_inds = np.append(fg_inds, bg_inds)#合并前景和背景框的index
# Select sampled values from various arrays:
labels = labels[keep_inds]
# Clamp labels for the background RoIs to 0
labels[fg_rois_per_this_image:] = 0#设定前景类别和背景类别
overlaps = overlaps[keep_inds]
rois = rois[keep_inds]
bbox_targets, bbox_inside_weights = _get_bbox_regression_labels(
roidb['bbox_targets'][keep_inds, :], num_classes)
return labels, overlaps, rois, bbox_targets, bbox_inside_weights
def _get_image_blob(roidb, scale_inds):
"""Builds an input blob from the images in the roidb at the specified
scales.
"""
num_images = len(roidb)
processed_ims = []
im_scales = []
for i in xrange(num_images):
im = cv2.imread(roidb[i]['image'])
if roidb[i]['flipped']:
im = im[:, ::-1, :]
target_size = cfg.TRAIN.SCALES[scale_inds[i]]
im, im_scale = prep_im_for_blob(im, cfg.PIXEL_MEANS, target_size,
cfg.TRAIN.MAX_SIZE)
im_scales.append(im_scale)
processed_ims.append(im)
# Create a blob to hold the input images
blob = im_list_to_blob(processed_ims)
return blob, im_scales
def _project_im_rois(im_rois, im_scale_factor):
"""Project image RoIs into the rescaled training image."""
rois = im_rois * im_scale_factor
return rois
def _get_bbox_regression_labels(bbox_target_data, num_classes):
"""Bounding-box regression targets are stored in a compact form in the
roidb.
This function expands those targets into the 4-of-4*K representation used
by the network (i.e. only one class has non-zero targets). The loss weights
are similarly expanded.
Returns:
bbox_target_data (ndarray): N x 4K blob of regression targets
bbox_inside_weights (ndarray): N x 4K blob of loss weights
"""
clss = bbox_target_data[:, 0]
bbox_targets = np.zeros((clss.size, 4 * num_classes), dtype=np.float32)
bbox_inside_weights = np.zeros(bbox_targets.shape, dtype=np.float32)
inds = np.where(clss > 0)[0]
for ind in inds:
cls = clss[ind]
start = 4 * cls
end = start + 4
bbox_targets[ind, start:end] = bbox_target_data[ind, 1:]
bbox_inside_weights[ind, start:end] = cfg.TRAIN.BBOX_INSIDE_WEIGHTS
return bbox_targets, bbox_inside_weights
def _vis_minibatch(im_blob, rois_blob, labels_blob, overlaps):
"""Visualize a mini-batch for debugging."""
import matplotlib.pyplot as plt
for i in xrange(rois_blob.shape[0]):
rois = rois_blob[i, :]
im_ind = rois[0]
roi = rois[1:]
im = im_blob[im_ind, :, :, :].transpose((1, 2, 0)).copy()
im += cfg.PIXEL_MEANS
im = im[:, :, (2, 1, 0)]
im = im.astype(np.uint8)
cls = labels_blob[i]
plt.imshow(im)
print 'class: ', cls, ' overlap: ', overlaps[i]
plt.gca().add_patch(
plt.Rectangle((roi[0], roi[1]), roi[2] - roi[0],
roi[3] - roi[1], fill=False,
edgecolor='r', linewidth=3)
)
plt.show()
========================================
下面一次是lib/rpn模块里的文件：
anchor_target_laryer.py定义了anchor_target层
import os
import caffe
import yaml
from fast_rcnn.config import cfg
import numpy as np
import numpy.random as npr
from generate_anchors import generate_anchors
from utils.cython_bbox import bbox_overlaps
from fast_rcnn.bbox_transform import bbox_transform
DEBUG = False
class AnchorTargetLayer(caffe.Layer):
"""
Assign anchors to ground-truth targets. Produces anchor classification
labels and bounding-box regression targets.
"""
def setup(self, bottom, top):#在初始化AnchorTargetLayer时候调用
self._anchors = generate_anchors()
self._num_anchors = self._anchors.shape[0]
if DEBUG:
print 'anchors:'
print self._anchors
print 'anchor shapes:'
print np.hstack((
self._anchors[:, 2::4] - self._anchors[:, 0::4],
self._anchors[:, 3::4] - self._anchors[:, 1::4],
))
self._counts = cfg.EPS
self._sums = np.zeros((1, 4))
self._squared_sums = np.zeros((1, 4))
self._fg_sum = 0
self._bg_sum = 0
self._count = 0
layer_params = yaml.load(self.param_str_)
self._feat_stride = layer_params['feat_stride']
# allow boxes to sit over the edge by a small amount
self._allowed_border = layer_params.get('allowed_border', 0)
height, width = bottom[0].data.shape[-2:]
if DEBUG:
print 'AnchorTargetLayer: height', height, 'width', width
A = self._num_anchors
# labels
top[0].reshape(1, 1, A * height, width)#根据前一层输出的高宽初始化该层输出top的大小
# bbox_targets
top[1].reshape(1, A * 4, height, width)
# bbox_inside_weights
top[2].reshape(1, A * 4, height, width)
# bbox_outside_weights
top[3].reshape(1, A * 4, height, width)
def forward(self, bottom, top):#整个项目最终要的一块，anchor的对应
# Algorithm:
#
# for each (H, W) location i
# generate 9 anchor boxes centered on cell i
# apply predicted bbox deltas at cell i to each of the 9 anchors
# filter out-of-image anchors
# measure GT overlap
assert bottom[0].data.shape[0] == 1, \
'Only single item batches are supported'
# map of shape (..., H, W)
height, width = bottom[0].data.shape[-2:]
# GT boxes (x1, y1, x2, y2, label)
gt_boxes = bottom[1].data
# im_info
im_info = bottom[2].data[0, :]
if 0 and DEBUG:
print ''
print 'im_size: ({}, {})'.format(im_info[0], im_info[1])
print 'scale: {}'.format(im_info[2])
print 'height, width: ({}, {})'.format(height, width)
#print 'rpn: gt_boxes.shape', gt_boxes.shape
#print 'rpn: gt_boxes', gt_boxes
# 1. Generate proposals from bbox deltas and shifted anchors
shift_x = np.arange(0, width) * self._feat_stride#根据base anchors在每个格子上生成9个anchors
shift_y = np.arange(0, height) * self._feat_stride
shift_x, shift_y = np.meshgrid(shift_x, shift_y)
shifts = np.vstack((shift_x.ravel(), shift_y.ravel(),
shift_x.ravel(), shift_y.ravel())).transpose()
# add A anchors (1, A, 4) to
# cell K shifts (K, 1, 4) to get
# shift anchors (K, A, 4)
# reshape to (K*A, 4) shifted anchors
A = self._num_anchors
K = shifts.shape[0]
all_anchors = (self._anchors.reshape((1, A, 4)) +
shifts.reshape((1, K, 4)).transpose((1, 0, 2)))
all_anchors = all_anchors.reshape((K * A, 4))
total_anchors = int(K * A)
# only keep anchors inside the image
inds_inside = np.where(
(all_anchors[:, 0] >= -self._allowed_border) &
(all_anchors[:, 1] >= -self._allowed_border) &
(all_anchors[:, 2] < im_info[1] + self._allowed_border) & # width
(all_anchors[:, 3] < im_info[0] + self._allowed_border) # height
)[0]
if DEBUG:
print 'total_anchors', total_anchors
print 'inds_inside', len(inds_inside)
# keep only inside anchors
anchors = all_anchors[inds_inside, :]
if DEBUG:
print 'anchors.shape', anchors.shape
# label: 1 is positive, 0 is negative, -1 is dont care
labels = np.empty((len(inds_inside), ), dtype=np.float32)
labels.fill(-1)
# overlaps between the anchors and the gt boxes
# overlaps (ex, gt)
overlaps = bbox_overlaps(
np.ascontiguousarray(anchors, dtype=np.float),
np.ascontiguousarray(gt_boxes, dtype=np.float))#计算所有anchors和gt boxes的覆盖率
argmax_overlaps = overlaps.argmax(axis=1)#每个anchors最大的overlap对应gt boxes的index
max_overlaps = overlaps[np.arange(len(inds_inside)), argmax_overlaps]#每个anchors最大overlap对应gt boxes的index的overlap值
gt_argmax_overlaps = overlaps.argmax(axis=0)#每个gt box最大覆盖率的index
gt_max_overlaps = overlaps[gt_argmax_overlaps,
np.arange(overlaps.shape[1])]#每个gt box最大的覆盖率值
gt_argmax_overlaps = np.where(overlaps == gt_max_overlaps)[0]#每个gt box最大的覆盖率的anchors的index
if not cfg.TRAIN.RPN_CLOBBER_POSITIVES:
# assign bg labels first so that positive labels can clobber them
labels[max_overlaps < cfg.TRAIN.RPN_NEGATIVE_OVERLAP] = 0#每个anchors和真值覆盖率小于cfg.TRAIN.RPN_NEGATIVE_OVERLAP的为负样本
# fg label: for each gt, anchor with highest overlap
labels[gt_argmax_overlaps] = 1#最大覆盖率的anchors为正样本
# fg label: above threshold IOU
labels[max_overlaps >= cfg.TRAIN.RPN_POSITIVE_OVERLAP] = 1#每个anchors和真值覆盖率大于cfg.TRAIN.RPN_POSITIVE_OVERLAP的为正样本
if cfg.TRAIN.RPN_CLOBBER_POSITIVES:
# assign bg labels last so that negative labels can clobber positives
labels[max_overlaps < cfg.TRAIN.RPN_NEGATIVE_OVERLAP] = 0
# subsample positive labels if we have too many
num_fg = int(cfg.TRAIN.RPN_FG_FRACTION * cfg.TRAIN.RPN_BATCHSIZE)#选择正负样本，总共256个，默认正负样本各一半，正样本不足时候负样本pad
fg_inds = np.where(labels == 1)[0]
if len(fg_inds) > num_fg:
disable_inds = npr.choice(
fg_inds, size=(len(fg_inds) - num_fg), replace=False)
labels[disable_inds] = -1
# subsample negative labels if we have too many
num_bg = cfg.TRAIN.RPN_BATCHSIZE - np.sum(labels == 1)
bg_inds = np.where(labels == 0)[0]
if len(bg_inds) > num_bg:
disable_inds = npr.choice(
bg_inds, size=(len(bg_inds) - num_bg), replace=False)
labels[disable_inds] = -1
#print "was %s inds, disabling %s, now %s inds" % (
#len(bg_inds), len(disable_inds), np.sum(labels == 0))
bbox_targets = np.zeros((len(inds_inside), 4), dtype=np.float32)
bbox_targets = _compute_targets(anchors, gt_boxes[argmax_overlaps, :])#计算box regression的偏移量
bbox_inside_weights = np.zeros((len(inds_inside), 4), dtype=np.float32)
bbox_inside_weights[labels == 1, :] = np.array(cfg.TRAIN.RPN_BBOX_INSIDE_WEIGHTS)#只有正样本有inside_weights
bbox_outside_weights = np.zeros((len(inds_inside), 4), dtype=np.float32)
if cfg.TRAIN.RPN_POSITIVE_WEIGHT < 0:
# uniform weighting of examples (given non-uniform sampling)
num_examples = np.sum(labels >= 0)
positive_weights = np.ones((1, 4)) * 1.0 / num_examples
negative_weights = np.ones((1, 4)) * 1.0 / num_examples
else:
assert ((cfg.TRAIN.RPN_POSITIVE_WEIGHT > 0) &
(cfg.TRAIN.RPN_POSITIVE_WEIGHT < 1))
positive_weights = (cfg.TRAIN.RPN_POSITIVE_WEIGHT /
np.sum(labels == 1))
negative_weights = ((1.0 - cfg.TRAIN.RPN_POSITIVE_WEIGHT) /
np.sum(labels == 0))
bbox_outside_weights[labels == 1, :] = positive_weights
bbox_outside_weights[labels == 0, :] = negative_weights#正负样本都有outside_weights
if DEBUG:
self._sums += bbox_targets[labels == 1, :].sum(axis=0)
self._squared_sums += (bbox_targets[labels == 1, :] ** 2).sum(axis=0)
self._counts += np.sum(labels == 1)
means = self._sums / self._counts
stds = np.sqrt(self._squared_sums / self._counts - means ** 2)
print 'means:'
print means
print 'stdevs:'
print stds
# map up to original set of anchors
labels = _unmap(labels, total_anchors, inds_inside, fill=-1)#映射回原有的anchor顺序
bbox_targets = _unmap(bbox_targets, total_anchors, inds_inside, fill=0)
bbox_inside_weights = _unmap(bbox_inside_weights, total_anchors, inds_inside, fill=0)
bbox_outside_weights = _unmap(bbox_outside_weights, total_anchors, inds_inside, fill=0)
if DEBUG:
print 'rpn: max max_overlap', np.max(max_overlaps)
print 'rpn: num_positive', np.sum(labels == 1)
print 'rpn: num_negative', np.sum(labels == 0)
self._fg_sum += np.sum(labels == 1)
self._bg_sum += np.sum(labels == 0)
self._count += 1
print 'rpn: num_positive avg', self._fg_sum / self._count
print 'rpn: num_negative avg', self._bg_sum / self._count
# labels
labels = labels.reshape((1, height, width, A)).transpose(0, 3, 1, 2)#填入输出top
labels = labels.reshape((1, 1, A * height, width))
top[0].reshape(*labels.shape)
top[0].data[...] = labels
# bbox_targets
bbox_targets = bbox_targets \
.reshape((1, height, width, A * 4)).transpose(0, 3, 1, 2)#填入输出top
top[1].reshape(*bbox_targets.shape)
top[1].data[...] = bbox_targets
# bbox_inside_weights
bbox_inside_weights = bbox_inside_weights \
.reshape((1, height, width, A * 4)).transpose(0, 3, 1, 2)#填入输出top
assert bbox_inside_weights.shape[2] == height
assert bbox_inside_weights.shape[3] == width
top[2].reshape(*bbox_inside_weights.shape)
top[2].data[...] = bbox_inside_weights
# bbox_outside_weights
bbox_outside_weights = bbox_outside_weights \
.reshape((1, height, width, A * 4)).transpose(0, 3, 1, 2)#填入输出top
assert bbox_outside_weights.shape[2] == height
assert bbox_outside_weights.shape[3] == width
top[3].reshape(*bbox_outside_weights.shape)
top[3].data[...] = bbox_outside_weights
def backward(self, top, propagate_down, bottom):
"""This layer does not propagate gradients."""
pass
def reshape(self, bottom, top):
"""Reshaping happens during the call to forward."""
pass
def _unmap(data, count, inds, fill=0):
""" Unmap a subset of item (data) back to the original set of items (of
size count) """
if len(data.shape) == 1:
ret = np.empty((count, ), dtype=np.float32)
ret.fill(fill)
ret[inds] = data
else:
ret = np.empty((count, ) + data.shape[1:], dtype=np.float32)
ret.fill(fill)
ret[inds, :] = data
return ret
def _compute_targets(ex_rois, gt_rois):
"""Compute bounding-box regression targets for an image."""
assert ex_rois.shape[0] == gt_rois.shape[0]
assert ex_rois.shape[1] == 4
assert gt_rois.shape[1] == 5
return bbox_transform(ex_rois, gt_rois[:, :4]).astype(np.float32, copy=False)
generate_anchors.py用来生成一个base anchor组，在这里可以自定义设置anchor的大小尺寸以及长宽比
import numpy as np
# Verify that we compute the same anchors as Shaoqing's matlab implementation:
#
# >> load output/rpn_cachedir/faster_rcnn_VOC2007_ZF_stage1_rpn/anchors.mat
# >> anchors
#
# anchors =
#
# -83 -39 100 56
# -175 -87 192 104
# -359 -183 376 200
# -55 -55 72 72
# -119 -119 136 136
# -247 -247 264 264
# -35 -79 52 96
# -79 -167 96 184
# -167 -343 184 360
#array([[ -83., -39., 100., 56.],
# [-175., -87., 192., 104.],
# [-359., -183., 376., 200.],
# [ -55., -55., 72., 72.],
# [-119., -119., 136., 136.],
# [-247., -247., 264., 264.],
# [ -35., -79., 52., 96.],
# [ -79., -167., 96., 184.],
# [-167., -343., 184., 360.]])
def generate_anchors(base_size=16, ratios=[0.5, 1, 2],
scales=2**np.arange(3, 6)):
"""
Generate anchor (reference) windows by enumerating aspect ratios X
scales wrt a reference (0, 0, 15, 15) window.
"""
base_anchor = np.array([1, 1, base_size, base_size]) - 1
ratio_anchors = _ratio_enum(base_anchor, ratios)
anchors = np.vstack([_scale_enum(ratio_anchors[i, :], scales)
for i in xrange(ratio_anchors.shape[0])])
return anchors
def _whctrs(anchor):
"""
Return width, height, x center, and y center for an anchor (window).
"""
w = anchor[2] - anchor[0] + 1
h = anchor[3] - anchor[1] + 1
x_ctr = anchor[0] + 0.5 * (w - 1)
y_ctr = anchor[1] + 0.5 * (h - 1)
return w, h, x_ctr, y_ctr
def _mkanchors(ws, hs, x_ctr, y_ctr):
"""
Given a vector of widths (ws) and heights (hs) around a center
(x_ctr, y_ctr), output a set of anchors (windows).
"""
ws = ws[:, np.newaxis]
hs = hs[:, np.newaxis]
anchors = np.hstack((x_ctr - 0.5 * (ws - 1),
y_ctr - 0.5 * (hs - 1),
x_ctr + 0.5 * (ws - 1),
y_ctr + 0.5 * (hs - 1)))
return anchors
def _ratio_enum(anchor, ratios):
"""
Enumerate a set of anchors for each aspect ratio wrt an anchor.
"""
w, h, x_ctr, y_ctr = _whctrs(anchor)
size = w * h
size_ratios = size / ratios
ws = np.round(np.sqrt(size_ratios))
hs = np.round(ws * ratios)
anchors = _mkanchors(ws, hs, x_ctr, y_ctr)
return anchors
def _scale_enum(anchor, scales):
"""
Enumerate a set of anchors for each scale wrt an anchor.
"""
w, h, x_ctr, y_ctr = _whctrs(anchor)
ws = w * scales
hs = h * scales
anchors = _mkanchors(ws, hs, x_ctr, y_ctr)
return anchors
if __name__ == '__main__':
import time
t = time.time()
a = generate_anchors()
print time.time() - t
print a
from IPython import embed; embed()
generate.py
from fast_rcnn.config import cfg
from utils.blob import im_list_to_blob
from utils.timer import Timer
import numpy as np
import cv2
def _vis_proposals(im, dets, thresh=0.5):
"""Draw detected bounding boxes."""
inds = np.where(dets[:, -1] >= thresh)[0]
if len(inds) == 0:
return
class_name = 'obj'
im = im[:, :, (2, 1, 0)]
fig, ax = plt.subplots(figsize=(12, 12))
ax.imshow(im, aspect='equal')
for i in inds:
bbox = dets[i, :4]
score = dets[i, -1]
ax.add_patch(
plt.Rectangle((bbox[0], bbox[1]),
bbox[2] - bbox[0],
bbox[3] - bbox[1], fill=False,
edgecolor='red', linewidth=3.5)
)
ax.text(bbox[0], bbox[1] - 2,
'{:s} {:.3f}'.format(class_name, score),
bbox=dict(facecolor='blue', alpha=0.5),
fontsize=14, color='white')
ax.set_title(('{} detections with '
'p({} | box) >= {:.1f}').format(class_name, class_name,
thresh),
fontsize=14)
plt.axis('off')
plt.tight_layout()
plt.draw()
def _get_image_blob(im):
"""Converts an image into a network input.
Arguments:
im (ndarray): a color image in BGR order
Returns:
blob (ndarray): a data blob holding an image pyramid
im_scale_factors (list): list of image scales (relative to im) used
in the image pyramid
"""
im_orig = im.astype(np.float32, copy=True)
im_orig -= cfg.PIXEL_MEANS
im_shape = im_orig.shape
im_size_min = np.min(im_shape[0:2])
im_size_max = np.max(im_shape[0:2])
processed_ims = []#对图像作尺度变换指定到对应的尺寸
assert len(cfg.TEST.SCALES) == 1
target_size = cfg.TEST.SCALES[0]#最短边的目标尺寸
im_scale = float(target_size) / float(im_size_min)
# Prevent the biggest axis from being more than MAX_SIZE
if np.round(im_scale * im_size_max) > cfg.TEST.MAX_SIZE:#如果按照这个比例缩放最长变超过给定大小就按长边缩放
im_scale = float(cfg.TEST.MAX_SIZE) / float(im_size_max)
im = cv2.resize(im_orig, None, None, fx=im_scale, fy=im_scale,
interpolation=cv2.INTER_LINEAR)
im_info = np.hstack((im.shape[:2], im_scale))[np.newaxis, :]
processed_ims.append(im)
# Create a blob to hold the input images
blob = im_list_to_blob(processed_ims)#将图像数据转换成blob, 1*Channel*H*W
return blob, im_info
def im_proposals(net, im):
"""Generate RPN proposals on a single image."""
blobs = {}
blobs['data'], blobs['im_info'] = _get_image_blob(im)#将图像转化为网络的输入
net.blobs['data'].reshape(*(blobs['data'].shape))#为网络的输入重新开辟空间
net.blobs['im_info'].reshape(*(blobs['im_info'].shape))#为网络的输入重新开辟空间
blobs_out = net.forward(
data=blobs['data'].astype(np.float32, copy=False),
im_info=blobs['im_info'].astype(np.float32, copy=False))
scale = blobs['im_info'][0, 2]
boxes = blobs_out['rois'][:, 1:].copy() / scale#boxes尺寸返回为原来图像上的尺寸
scores = blobs_out['scores'].copy()
return boxes, scores
def imdb_proposals(net, imdb):
"""Generate RPN proposals on all images in an imdb."""
_t = Timer()
imdb_boxes = [[] for _ in xrange(imdb.num_images)]
for i in xrange(imdb.num_images):
im = cv2.imread(imdb.image_path_at(i))
_t.tic()
imdb_boxes[i], scores = im_proposals(net, im)#生成置信度最高的RPNs boxes+scores
_t.toc()
print 'im_proposals: {:d}/{:d} {:.3f}s' \
.format(i + 1, imdb.num_images, _t.average_time)
if 0:
dets = np.hstack((imdb_boxes[i], scores))
# from IPython import embed; embed()
_vis_proposals(im, dets[:3, :], thresh=0.9)
plt.show()
return imdb_boxes
proposal_layer.py
import caffe
import numpy as np
import yaml
from fast_rcnn.config import cfg
from generate_anchors import generate_anchors
from fast_rcnn.bbox_transform import bbox_transform_inv, clip_boxes
from fast_rcnn.nms_wrapper import nms
DEBUG = False
class ProposalLayer(caffe.Layer):
"""
Outputs object detection proposals by applying estimated bounding-box
transformations to a set of regular boxes (called "anchors").
"""
def setup(self, bottom, top):
# parse the layer parameter string, which must be valid YAML
layer_params = yaml.load(self.param_str_)
self._feat_stride = layer_params['feat_stride']#这里的feat_stride表示最后一个feature map的尺度和原始图像的比例，比如原来是800*800最后一个feature map是50*50，那feat_stride是800/50=16
self._anchors = generate_anchors()
self._num_anchors = self._anchors.shape[0]
if DEBUG:
print 'feat_stride: {}'.format(self._feat_stride)
print 'anchors:'
print self._anchors
# rois blob: holds R regions of interest, each is a 5-tuple
# (n, x1, y1, x2, y2) specifying an image batch index n and a
# rectangle (x1, y1, x2, y2)
top[0].reshape(1, 5)
# scores blob: holds scores for R regions of interest
if len(top) > 1:
top[1].reshape(1, 1, 1, 1)
def forward(self, bottom, top):
# Algorithm:
#
# for each (H, W) location i
# generate A anchor boxes centered on cell i
# apply predicted bbox deltas at cell i to each of the A anchors
# clip predicted boxes to image
# remove predicted boxes with either height or width < threshold
# sort all (proposal, score) pairs by score from highest to lowest
# take top pre_nms_topN proposals before NMS
# apply NMS with threshold 0.7 to remaining proposals
# take after_nms_topN proposals after NMS
# return the top proposals (-> RoIs top, scores top)
assert bottom[0].data.shape[0] == 1, \
'Only single item batches are supported'
cfg_key = str(self.phase) # either 'TRAIN' or 'TEST'
pre_nms_topN = cfg[cfg_key].RPN_PRE_NMS_TOP_N
post_nms_topN = cfg[cfg_key].RPN_POST_NMS_TOP_N
nms_thresh = cfg[cfg_key].RPN_NMS_THRESH
min_size = cfg[cfg_key].RPN_MIN_SIZE
# the first set of _num_anchors channels are bg probs
# the second set are the fg probs, which we want
scores = bottom[0].data[:, self._num_anchors:, :, :]#这里bottom尺寸为1*（2*9）*w*h,后9个为前景的概率
bbox_deltas = bottom[1].data#网络学习的box deltas值，这里每个anchor对应一组deltas,所以每个anchor对应一个属于前景的概率和box delta值，通过box regression的deltas和对应anchor值获得预测框
im_info = bottom[2].data[0, :]
if DEBUG:
print 'im_size: ({}, {})'.format(im_info[0], im_info[1])
print 'scale: {}'.format(im_info[2])
# 1. Generate proposals from bbox deltas and shifted anchors
height, width = scores.shape[-2:]
if DEBUG:
print 'score map size: {}'.format(scores.shape)
# Enumerate all shifts
shift_x = np.arange(0, width) * self._feat_stride
shift_y = np.arange(0, height) * self._feat_stride
shift_x, shift_y = np.meshgrid(shift_x, shift_y)
shifts = np.vstack((shift_x.ravel(), shift_y.ravel(),
shift_x.ravel(), shift_y.ravel())).transpose()#生成所有anchors
# Enumerate all shifted anchors:
#
# add A anchors (1, A, 4) to
# cell K shifts (K, 1, 4) to get
# shift anchors (K, A, 4)
# reshape to (K*A, 4) shifted anchors
A = self._num_anchors
K = shifts.shape[0]
anchors = self._anchors.reshape((1, A, 4)) + \
shifts.reshape((1, K, 4)).transpose((1, 0, 2))
anchors = anchors.reshape((K * A, 4))
# Transpose and reshape predicted bbox transformations to get them
# into the same order as the anchors:
#
# bbox deltas will be (1, 4 * A, H, W) format
# transpose to (1, H, W, 4 * A)
# reshape to (1 * H * W * A, 4) where rows are ordered by (h, w, a)
# in slowest to fastest order
bbox_deltas = bbox_deltas.transpose((0, 2, 3, 1)).reshape((-1, 4))
# Same story for the scores:
#
# scores are (1, A, H, W) format
# transpose to (1, H, W, A)
# reshape to (1 * H * W * A, 1) where rows are ordered by (h, w, a)
scores = scores.transpose((0, 2, 3, 1)).reshape((-1, 1))#将bbox_deltas和scores对应reshape成二维大小
# Convert anchors into proposals via bbox transformations
proposals = bbox_transform_inv(anchors, bbox_deltas)#由box delta值还原boxes
# 2. clip predicted boxes to image
proposals = clip_boxes(proposals, im_info[:2])#将坐标框限定在有效大小内
# 3. remove predicted boxes with either height or width < threshold
# (NOTE: convert min_size to input image scale stored in im_info[2])
keep = _filter_boxes(proposals, min_size * im_info[2])
proposals = proposals[keep, :]
scores = scores[keep]
# 4. sort all (proposal, score) pairs by score from highest to lowest
# 5. take top pre_nms_topN (e.g. 6000)
order = scores.ravel().argsort()[::-1]
if pre_nms_topN > 0:
order = order[:pre_nms_topN]
proposals = proposals[order, :]
scores = scores[order]
# 6. apply nms (e.g. threshold = 0.7)
# 7. take after_nms_topN (e.g. 300)
# 8. return the top proposals (-> RoIs top)
keep = nms(np.hstack((proposals, scores)), nms_thresh)
if post_nms_topN > 0:
keep = keep[:post_nms_topN]
proposals = proposals[keep, :]
scores = scores[keep]
# Output rois blob
# Our RPN implementation only supports a single input image, so all
# batch inds are 0
batch_inds = np.zeros((proposals.shape[0], 1), dtype=np.float32)
blob = np.hstack((batch_inds, proposals.astype(np.float32, copy=False)))
top[0].reshape(*(blob.shape))
top[0].data[...] = blob
# [Optional] output scores blob
if len(top) > 1:
top[1].reshape(*(scores.shape))
top[1].data[...] = scores
def backward(self, top, propagate_down, bottom):
"""This layer does not propagate gradients."""
pass
def reshape(self, bottom, top):
"""Reshaping happens during the call to forward."""
pass
def _filter_boxes(boxes, min_size):
"""Remove all boxes with any side smaller than min_size."""
ws = boxes[:, 2] - boxes[:, 0] + 1
hs = boxes[:, 3] - boxes[:, 1] + 1
keep = np.where((ws >= min_size) & (hs >= min_size))[0]
return keep
proposal_target_layer.py
import caffe
import yaml
import numpy as np
import numpy.random as npr
from fast_rcnn.config import cfg
from fast_rcnn.bbox_transform import bbox_transform
from generate_anchors import generate_anchors
from utils.cython_bbox import bbox_overlaps
DEBUG = False
class ProposalTargetLayer(caffe.Layer):
"""
Assign object detection proposals to ground-truth targets. Produces proposal
classification labels and bounding-box regression targets.
"""
def setup(self, bottom, top):
self._anchors = generate_anchors()
self._num_anchors = self._anchors.shape[0]
if DEBUG:
print 'anchors:'
print self._anchors
self._count = 0
self._fg_num = 0
self._bg_num = 0
layer_params = yaml.load(self.param_str_)
self._num_classes = layer_params['num_classes']
# sampled rois (0, x1, y1, x2, y2)
top[0].reshape(1, 5)
# labels
top[1].reshape(1, 1)
# bbox_targets
top[2].reshape(1, self._num_classes * 4)
# bbox_inside_weights
top[3].reshape(1, self._num_classes * 4)
# bbox_outside_weights
top[4].reshape(1, self._num_classes * 4)
def forward(self, bottom, top):
# Proposal ROIs (0, x1, y1, x2, y2) coming from RPN
# (i.e., rpn.proposal_layer.ProposalLayer), or any other source
all_rois = bottom[0].data
# GT boxes (x1, y1, x2, y2, label)
# TODO(rbg): it's annoying that sometimes I have extra info before
# and other times after box coordinates -- normalize to one format
gt_boxes = bottom[1].data
# Include ground-truth boxes in the set of candidate rois
zeros = np.zeros((gt_boxes.shape[0], 1), dtype=gt_boxes.dtype)
all_rois = np.vstack(
(all_rois, np.hstack((zeros, gt_boxes[:, :-1])))
)
# Sanity check: single batch only
assert np.all(all_rois[:, 0] == 0), \
'Only single item batches are supported'
num_images = 1
rois_per_image = cfg.TRAIN.BATCH_SIZE / num_images
fg_rois_per_image = np.round(cfg.TRAIN.FG_FRACTION * rois_per_image)
# Sample rois with classification labels and bounding box regression
# targets
labels, rois, bbox_targets, bbox_inside_weights = _sample_rois(
all_rois, gt_boxes, fg_rois_per_image,
rois_per_image, self._num_classes)
if DEBUG:
print 'num fg: {}'.format((labels > 0).sum())
print 'num bg: {}'.format((labels == 0).sum())
self._count += 1
self._fg_num += (labels > 0).sum()
self._bg_num += (labels == 0).sum()
print 'num fg avg: {}'.format(self._fg_num / self._count)
print 'num bg avg: {}'.format(self._bg_num / self._count)
print 'ratio: {:.3f}'.format(float(self._fg_num) / float(self._bg_num))
# sampled rois
top[0].reshape(*rois.shape)
top[0].data[...] = rois
# classification labels
top[1].reshape(*labels.shape)
top[1].data[...] = labels
# bbox_targets
top[2].reshape(*bbox_targets.shape)
top[2].data[...] = bbox_targets
# bbox_inside_weights
top[3].reshape(*bbox_inside_weights.shape)
top[3].data[...] = bbox_inside_weights
# bbox_outside_weights
top[4].reshape(*bbox_inside_weights.shape)
top[4].data[...] = np.array(bbox_inside_weights > 0).astype(np.float32)
def backward(self, top, propagate_down, bottom):
"""This layer does not propagate gradients."""
pass
def reshape(self, bottom, top):
"""Reshaping happens during the call to forward."""
pass
def _get_bbox_regression_labels(bbox_target_data, num_classes):
"""Bounding-box regression targets (bbox_target_data) are stored in a
compact form N x (class, tx, ty, tw, th)
This function expands those targets into the 4-of-4*K representation used
by the network (i.e. only one class has non-zero targets).
Returns:
bbox_target (ndarray): N x 4K blob of regression targets
bbox_inside_weights (ndarray): N x 4K blob of loss weights
"""
clss = bbox_target_data[:, 0]
bbox_targets = np.zeros((clss.size, 4 * num_classes), dtype=np.float32)
bbox_inside_weights = np.zeros(bbox_targets.shape, dtype=np.float32)
inds = np.where(clss > 0)[0]
for ind in inds:
cls = clss[ind]
start = 4 * cls
end = start + 4
bbox_targets[ind, start:end] = bbox_target_data[ind, 1:]
bbox_inside_weights[ind, start:end] = cfg.TRAIN.BBOX_INSIDE_WEIGHTS
return bbox_targets, bbox_inside_weights
def _compute_targets(ex_rois, gt_rois, labels):
"""Compute bounding-box regression targets for an image."""
assert ex_rois.shape[0] == gt_rois.shape[0]
assert ex_rois.shape[1] == 4
assert gt_rois.shape[1] == 4
targets = bbox_transform(ex_rois, gt_rois)
if cfg.TRAIN.BBOX_NORMALIZE_TARGETS_PRECOMPUTED:
# Optionally normalize targets by a precomputed mean and stdev
targets = ((targets - np.array(cfg.TRAIN.BBOX_NORMALIZE_MEANS))
/ np.array(cfg.TRAIN.BBOX_NORMALIZE_STDS))
return np.hstack(
(labels[:, np.newaxis], targets)).astype(np.float32, copy=False)
def _sample_rois(all_rois, gt_boxes, fg_rois_per_image, rois_per_image, num_classes):
"""Generate a random sample of RoIs comprising foreground and background
examples.
"""
# overlaps: (rois x gt_boxes)
overlaps = bbox_overlaps(
np.ascontiguousarray(all_rois[:, 1:5], dtype=np.float),
np.ascontiguousarray(gt_boxes[:, :4], dtype=np.float))
gt_assignment = overlaps.argmax(axis=1)
max_overlaps = overlaps.max(axis=1)
labels = gt_boxes[gt_assignment, 4]
# Select foreground RoIs as those with >= FG_THRESH overlap
fg_inds = np.where(max_overlaps >= cfg.TRAIN.FG_THRESH)[0]
# Guard against the case when an image has fewer than fg_rois_per_image
# foreground RoIs
fg_rois_per_this_image = min(fg_rois_per_image, fg_inds.size)
# Sample foreground regions without replacement
if fg_inds.size > 0:
fg_inds = npr.choice(fg_inds, size=fg_rois_per_this_image, replace=False)
# Select background RoIs as those within [BG_THRESH_LO, BG_THRESH_HI)
bg_inds = np.where((max_overlaps < cfg.TRAIN.BG_THRESH_HI) &
(max_overlaps >= cfg.TRAIN.BG_THRESH_LO))[0]
# Compute number of background RoIs to take from this image (guarding
# against there being fewer than desired)
bg_rois_per_this_image = rois_per_image - fg_rois_per_this_image
bg_rois_per_this_image = min(bg_rois_per_this_image, bg_inds.size)
# Sample background regions without replacement
if bg_inds.size > 0:
bg_inds = npr.choice(bg_inds, size=bg_rois_per_this_image, replace=False)
# The indices that we're selecting (both fg and bg)
keep_inds = np.append(fg_inds, bg_inds)
# Select sampled values from various arrays:
labels = labels[keep_inds]
# Clamp labels for the background RoIs to 0
labels[fg_rois_per_this_image:] = 0
rois = all_rois[keep_inds]
bbox_target_data = _compute_targets(
rois[:, 1:5], gt_boxes[gt_assignment[keep_inds], :4], labels)
bbox_targets, bbox_inside_weights = \
_get_bbox_regression_labels(bbox_target_data, num_classes)
return labels, rois, bbox_targets, bbox_inside_weights
========================================
下面一次是lib/utils模块里的文件：
blob.py
"""Blob helper functions."""
import numpy as np
import cv2
def im_list_to_blob(ims):
"""Convert a list of images into a network input.
Assumes images are already prepared (means subtracted, BGR order, ...).
"""
max_shape = np.array([im.shape for im in ims]).max(axis=0)
num_images = len(ims)
blob = np.zeros((num_images, max_shape[0], max_shape[1], 3),
dtype=np.float32)
for i in xrange(num_images):
im = ims[i]
blob[i, 0:im.shape[0], 0:im.shape[1], :] = im
# Move channels (axis 3) to axis 1
# Axis order will become: (batch elem, channel, height, width)
channel_swap = (0, 3, 1, 2)
blob = blob.transpose(channel_swap)
return blob
def prep_im_for_blob(im, pixel_means, target_size, max_size):#对图像做指定的处理，减均值，resize
"""Mean subtract and scale an image for use in a blob."""
im = im.astype(np.float32, copy=False)
im -= pixel_means
im_shape = im.shape
im_size_min = np.min(im_shape[0:2])
im_size_max = np.max(im_shape[0:2])
im_scale = float(target_size) / float(im_size_min)
# Prevent the biggest axis from being more than MAX_SIZE
if np.round(im_scale * im_size_max) > max_size:
im_scale = float(max_size) / float(im_size_max)
im = cv2.resize(im, None, None, fx=im_scale, fy=im_scale,
interpolation=cv2.INTER_LINEAR)
return im, im_scale
timer.py
import time
class Timer(object):
"""A simple timer."""
def __init__(self):
self.total_time = 0.
self.calls = 0
self.start_time = 0.
self.diff = 0.
self.average_time = 0.
def tic(self):
# using time.time instead of time.clock because time time.clock
# does not normalize for multithreading
self.start_time = time.time()
def toc(self, average=True):
self.diff = time.time() - self.start_time
self.total_time += self.diff
self.calls += 1
self.average_time = self.total_time / self.calls
if average:
return self.average_time
else:
return self.diff
看我写的辛苦求打赏啊！！！有学术讨论和指点请加微信manutdzou,注明
