天天看點

Faster-RCNN_TF代碼解讀6:pascal_voc.py

# --------------------------------------------------------
# Fast R-CNN
# Copyright (c) 2015 Microsoft
# Licensed under The MIT License [see LICENSE for details]
# Written by Ross Girshick
# --------------------------------------------------------

import os
from datasets.imdb import imdb
import datasets.ds_utils as ds_utils
import xml.etree.ElementTree as ET
import numpy as np
import scipy.sparse
import scipy.io as sio
import utils.cython_bbox
import cPickle
import subprocess
import uuid
from voc_eval import voc_eval
from fast_rcnn.config import cfg
import pdb

#pascal_voc繼承imdb
class pascal_voc(imdb):
    #傳進來的第一個參數為資料集名稱(train,val,test...),第二個參數為版本,如2007,devkit_path暫時為空
    def __init__(self, image_set, year, devkit_path=None):
        #調用imdb的構造函數,傳進去參數格式為“voc_year_imageset”--例如voc_2007_train,其實就是記錄了一下self._name,其餘的為預設,
        #其餘預設參數有(self._num_classes,self._classes,self._image_index,self._obj_proposer,self._roidb,self._roidb_handler,self.config)
        imdb.__init__(self, 'voc_' + year + '_' + image_set)
        self._year = year
        self._image_set = image_set
        #devikit_path在不給定下為None,此時self._devkit_path為Fsater - RCNN_TF / data / VOCdevkit+self._year
        self._devkit_path = self._get_default_path() if devkit_path is None \
                            else devkit_path
        #為Fsater - RCNN_TF / data / VOCdevkit +'year'/'VOC' + self._year
        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')
        #在imdb中定義self.classes即為self._classes,self.num_classes為len(self._classes)
        #self._class_to_ind裡存的是{'__background__':0,'aeroplane':1.....}
        self._class_to_ind = dict(zip(self.classes, xrange(self.num_classes)))
        #圖檔格式
        self._image_ext = '.jpg'
        #一個清單,包含對應資料集圖像名稱資訊,如[000001,000007,...,000267]
        self._image_index = self._load_image_set_index()
        # Default to roidb handler
        #self._roidb_handler = self.selective_search_roidb
        #得到roi圖檔資訊,重載imdb中
        self._roidb_handler = self.gt_roidb
        #生成一個随機的uuid,即對于分布式資料,每個資料都有自己對應的唯一的辨別符,uuid4是根據随機數生成機制,前面随機數種子已經定義了np.random.seed(3)
        self._salt = str(uuid.uuid4())
        self._comp_id = 'comp4'

        # PASCAL specific config options
        self.config = {'cleanup'     : True,
                       'use_salt'    : True,
                       'use_diff'    : False,
                       'matlab_eval' : False,
                       'rpn_file'    : None,
                       'min_size'    : }

        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)
    #重載了imdb.py中定義,傳回圖檔所在全路徑
    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])
    #image_path_at中調用,組合圖檔所在全路徑
    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):
        #擷取圖檔引索
        """
        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:
            #http://www.cnblogs.com/itdyb/p/5046472.html
            #x.strip()就是當括号内為空就删除x開頭與結尾的('/n','/t',' ')
            #如果括号内有不為空,x.strip(XX)就在x的開頭和結尾删除XX
            #還有隻管開頭lstrip(),結尾rstrip()
            image_index = [x.strip() for x in f.readlines()]
        #傳回的image_index為一個清單,包含該資料集圖檔名稱資訊(之前做VOC資料集時候就有在對應txt中,是沒有.jpg字尾的,這是為了讓你友善修改代碼,制作自己的資料集)
        return image_index

    def _get_default_path(self):
        """
        Return the default path where PASCAL VOC is expected to be installed.
        """
        #由config.py可知_get_default_path傳回的是 Fsater-RCNN_TF/data/VOCdevkit+self._year
        return os.path.join(cfg.DATA_DIR, 'VOCdevkit' + self._year)

    def gt_roidb(self):
        #得到ROI組成的database
        """
        Return the database of ground-truth regions of interest.

        This function loads/saves from/to a cache file to speed up future calls.
        """
        #cache_path=abs(Fsater-RCNN_TF/data/cache),self.name為voc_' + year + '_' + image_set
        # 則cache_file為abs(Fsater-RCNN_TF/data/cache)/'voc_' + year + '_' + image_set+'_gt_roidb.pkl'
        #例如Fsater-RCNN_TF/data/cache/voc_2007_train__gt_roidb.pkl
        cache_file = os.path.join(self.cache_path, self.name + '_gt_roidb.pkl')
        #加載cache_file至roidb
        if os.path.exists(cache_file):
            with open(cache_file, 'rb') as fid:
                #b=cPickle.load(a).加載a至b
                #d=cPickle.dump(c,fid, cPickle.HIGHEST_PROTOCOL).把c存到fid,一種高效的加載方式cPickle.HIGHEST_PROTOCOL,可使得節省80%空間
                roidb = cPickle.load(fid)
            print '{} gt roidb loaded from {}'.format(self.name, cache_file)
            return roidb
        #self._load_pascal_annotation(index)傳回的是該圖檔資訊dict,然後按順序存進一個list,對應圖檔資訊引索與self.image_index引索相對應
        gt_roidb = [self._load_pascal_annotation(index)
                    for index in self.image_index]
        #将gt_roidb存入臨時檔案cache_file
        with open(cache_file, 'wb') as fid:
            cPickle.dump(gt_roidb, fid, cPickle.HIGHEST_PROTOCOL)
        print 'wrote gt roidb to {}'.format(cache_file)
        #傳回gt_roidb
        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) ==  or self._image_set != 'test':
            gt_roidb = self.gt_roidb()
            ss_roidb = self._load_selective_search_roidb(gt_roidb)
            roidb = 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):
        if int(self._year) ==  or self._image_set != 'test':
            gt_roidb = self.gt_roidb()
            rpn_roidb = self._load_rpn_roidb(gt_roidb)
            roidb = 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(cfg.DATA_DIR,
                                                '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[]):
            boxes = raw_data[i][:, (, , , )] - 
            keep = ds_utils.unique_boxes(boxes)
            boxes = boxes[keep, :]
            keep = ds_utils.filter_small_boxes(boxes, self.config['min_size'])
            boxes = boxes[keep, :]
            box_list.append(boxes)

        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.
        """
        #定位Fsater - RCNN_TF / data / VOCdevkit +'year'/'VOC' + self._year/Annotations/000001.xml
        filename = os.path.join(self._data_path, 'Annotations', index + '.xml')
        #用xml.etree.ElementTree打開XML檔案
        tree = ET.parse(filename)

        objs = tree.findall('object')
        if not self.config['use_diff']:
            # Exclude the samples labeled as difficult
            #xml檔案中該object有一個屬性difficult,1表示目标難以區分,0表示容易識别、
            #該操作就是要吧有difficult的目标給剔除
            non_diff_objs = [
                obj for obj in objs if int(obj.find('difficult').text) == ]
            # 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)
        #初始化boxes,先建立一個shape為(num_objs, 4)的全零矩陣,num_objs為該引索圖檔中物體的個數,如有兩隻貓,則num_objs=2
        boxes = np.zeros((num_objs, ), dtype=np.uint16)
        #初始化gt_classes,shape為(num_objs)
        gt_classes = np.zeros((num_objs), dtype=np.int32)
        #overlaps(重疊),shape(num_objs, self.num_classes),self.num_classes為之前定義的所有分類的個數
        overlaps = np.zeros((num_objs, self.num_classes), dtype=np.float32)
        # "Seg" area for pascal is just the box area
        #初始化seg_areas,shape為(num_objs)
        seg_areas = np.zeros((num_objs), dtype=np.float32)

        # Load object bounding boxes into a data frame.
        #對每一個objs中的obj進行操作
        for ix, obj in enumerate(objs):
            bbox = obj.find('bndbox')
            # Make pixel indexes 0-based
            #記錄objs的bbox值
            x1 = float(bbox.find('xmin').text) - 
            y1 = float(bbox.find('ymin').text) - 
            x2 = float(bbox.find('xmax').text) - 
            y2 = float(bbox.find('ymax').text) - 
            #之前已經定義好的self._class_to_ind裡存的是{'__background__':0,'aeroplane':1.....}
            #取出目前obj的name,變小寫,去除字元串頭尾 '/n','/t',' ',然後取出對應字典中的引索值,如aeroplane的cls為1
            cls = self._class_to_ind[obj.find('name').text.lower().strip()]
            #e.g. boxes為([貓1的四個bbox值],[貓2的四個bbox值]..)
            boxes[ix, :] = [x1, y1, x2, y2]
            #e.g. (1,7,10,4..)
            gt_classes[ix] = cls
            #e.g. 生成類似與one-hot編碼[[0,0,0,0,1,0,0,0,][0,0,0,0,1,0,0,0,]]
            overlaps[ix, cls] = 
            #計算bbox面積
            seg_areas[ix] = (x2 - x1 + ) * (y2 - y1 + )
        #将overlaps稀疏矩陣壓縮
        overlaps = scipy.sparse.csr_matrix(overlaps)
        #總結類型:以下key的類型依次為array、array、scipy.sparse.csr.csr_matrix、bool、array
        return {'boxes' : boxes,
                'gt_classes': gt_classes,
                'gt_overlaps' : overlaps,
                'flipped' : False,
                'seg_areas' : seg_areas}

    def _get_comp_id(self):
        comp_id = (self._comp_id + '_' + self._salt if self.config['use_salt']
            else self._comp_id)
        return comp_id

    def _get_voc_results_file_template(self):
        # VOCdevkit/results/VOC2007/Main/<comp_id>_det_test_aeroplane.txt
        filename = self._get_comp_id() + '_det_' + self._image_set + '_{:s}.txt'
        path = os.path.join(
            self._devkit_path,
            'results',
            'VOC' + self._year,
            'Main',
            filename)
        return path

    def _write_voc_results_file(self, all_boxes):
        for cls_ind, cls in enumerate(self.classes):
            if cls == '__background__':
                continue
            print 'Writing {} VOC results file'.format(cls)
            filename = self._get_voc_results_file_template().format(cls)
            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[]):
                        f.write('{:s} {:.3f} {:.1f} {:.1f} {:.1f} {:.1f}\n'.
                                format(index, dets[k, -],
                                       dets[k, ] + , dets[k, ] + ,
                                       dets[k, ] + , dets[k, ] + ))

    def _do_python_eval(self, output_dir = 'output'):
        annopath = os.path.join(
            self._devkit_path,
            'VOC' + self._year,
            'Annotations',
            '{:s}.xml')
        imagesetfile = os.path.join(
            self._devkit_path,
            'VOC' + self._year,
            'ImageSets',
            'Main',
            self._image_set + '.txt')
        cachedir = os.path.join(self._devkit_path, 'annotations_cache')
        aps = []
        # The PASCAL VOC metric changed in 2010
        use_07_metric = True if int(self._year) <  else False
        print 'VOC07 metric? ' + ('Yes' if use_07_metric else 'No')
        if not os.path.isdir(output_dir):
            os.mkdir(output_dir)
        for i, cls in enumerate(self._classes):
            if cls == '__background__':
                continue
            filename = self._get_voc_results_file_template().format(cls)
            rec, prec, ap = voc_eval(
                filename, annopath, imagesetfile, cls, cachedir, ovthresh=,
                use_07_metric=use_07_metric)
            aps += [ap]
            print('AP for {} = {:.4f}'.format(cls, ap))
            with open(os.path.join(output_dir, cls + '_pr.pkl'), 'w') as f:
                cPickle.dump({'rec': rec, 'prec': prec, 'ap': ap}, f)
        print('Mean AP = {:.4f}'.format(np.mean(aps)))
        print('~~~~~~~~')
        print('Results:')
        for ap in aps:
            print('{:.3f}'.format(ap))
        print('{:.3f}'.format(np.mean(aps)))
        print('~~~~~~~~')
        print('')
        print('--------------------------------------------------------------')
        print('Results computed with the **unofficial** Python eval code.')
        print('Results should be very close to the official MATLAB eval code.')
        print('Recompute with `./tools/reval.py --matlab ...` for your paper.')
        print('-- Thanks, The Management')
        print('--------------------------------------------------------------')

    def _do_matlab_eval(self, output_dir='output'):
        print '-----------------------------------------------------'
        print 'Computing results with the official MATLAB eval code.'
        print '-----------------------------------------------------'
        path = os.path.join(cfg.ROOT_DIR, 'lib', 'datasets',
                            'VOCdevkit-matlab-wrapper')
        cmd = 'cd {} && '.format(path)
        cmd += '{:s} -nodisplay -nodesktop '.format(cfg.MATLAB)
        cmd += '-r "dbstop if error; '
        cmd += 'voc_eval(\'{:s}\',\'{:s}\',\'{:s}\',\'{:s}\'); quit;"' \
               .format(self._devkit_path, self._get_comp_id(),
                       self._image_set, output_dir)
        print('Running:\n{}'.format(cmd))
        status = subprocess.call(cmd, shell=True)

    def evaluate_detections(self, all_boxes, output_dir):
        self._write_voc_results_file(all_boxes)
        self._do_python_eval(output_dir)
        if self.config['matlab_eval']:
            self._do_matlab_eval(output_dir)
        if self.config['cleanup']:
            for cls in self._classes:
                if cls == '__background__':
                    continue
                filename = self._get_voc_results_file_template().format(cls)
                os.remove(filename)

    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__':
    from datasets.pascal_voc import pascal_voc
    d = pascal_voc('trainval', '2007')
    res = d.roidb
    #
    from IPython import embed; embed()