openpose pytorch代码分析

github: https://github.com/tensorboy/pytorch_Realtime_Multi-Person_Pose_Estimation

 # -*- coding: utf-8 -*
 import os
 import re
 import sys
 import cv2
 import math
 import time
 import scipy
 import argparse
 import matplotlib
 import numpy as np
 import pylab as plt
 from joblib import Parallel, delayed
 import util
 import torch
 import torch as T
 import torch.nn as nn
 import torch.nn.functional as F
 from torch.autograd import Variable
 from collections import OrderedDict
 from config_reader import config_reader
 from scipy.ndimage.filters import gaussian_filter
 #parser = argparse.ArgumentParser()
 #parser.add_argument('--t7_file', required=True)
 #parser.add_argument('--pth_file', required=True)
 #args = parser.parse_args()

 torch.set_num_threads(torch.get_num_threads())
 weight_name = './model/pose_model.pth'

 blocks = {}
 # 从1开始算的limb,图对应:Pose Output Format
 # find connection in the specified sequence, center 29 is in the position 15
 limbSeq = [[2,3], [2,6], [3,4], [4,5], [6,7], [7,8], [2,9], [9,10], \
            [10,11], [2,12], [12,13], [13,14], [2,1], [1,15], [15,17], \
            [1,16], [16,18], [3,17], [6,18]]

 # the middle joints heatmap correpondence
 mapIdx = [[31,32], [39,40], [33,34], [35,36], [41,42], [43,44], [19,20], [21,22], \
           [23,24], [25,26], [27,28], [29,30], [47,48], [49,50], [53,54], [51,52], \
           [55,56], [37,38], [45,46]]

 # visualize
 colors = [[255, 0, 0], [255, 85, 0], [255, 170, 0], [255, 255, 0], [170, 255, 0], [85, 255, 0], [0, 255, 0], \
           [0, 255, 85], [0, 255, 170], [0, 255, 255], [0, 170, 255], [0, 85, 255], [0, 0, 255], [85, 0, 255], \
           [170, 0, 255], [255, 0, 255], [255, 0, 170], [255, 0, 85]]

 # heatmap channel为19 表示关节点的score
 # PAF channel为38 表示limb的单位向量
 block0  = [{'conv1_1':[3,64,3,1,1]},{'conv1_2':[64,64,3,1,1]},{'pool1_stage1':[2,2,0]},{'conv2_1':[64,128,3,1,1]},{'conv2_2':[128,128,3,1,1]},{'pool2_stage1':[2,2,0]},{'conv3_1':[128,256,3,1,1]},{'conv3_2':[256,256,3,1,1]},{'conv3_3':[256,256,3,1,1]},{'conv3_4':[256,256,3,1,1]},{'pool3_stage1':[2,2,0]},{'conv4_1':[256,512,3,1,1]},{'conv4_2':[512,512,3,1,1]},{'conv4_3_CPM':[512,256,3,1,1]},{'conv4_4_CPM':[256,128,3,1,1]}]

 blocks['block1_1']  = [{'conv5_1_CPM_L1':[128,128,3,1,1]},{'conv5_2_CPM_L1':[128,128,3,1,1]},{'conv5_3_CPM_L1':[128,128,3,1,1]},{'conv5_4_CPM_L1':[128,512,1,1,0]},{'conv5_5_CPM_L1':[512,38,1,1,0]}]

 blocks['block1_2']  = [{'conv5_1_CPM_L2':[128,128,3,1,1]},{'conv5_2_CPM_L2':[128,128,3,1,1]},{'conv5_3_CPM_L2':[128,128,3,1,1]},{'conv5_4_CPM_L2':[128,512,1,1,0]},{'conv5_5_CPM_L2':[512,19,1,1,0]}]

 for i in range(2,7):
     blocks['block%d_1'%i]  = [{'Mconv1_stage%d_L1'%i:[185,128,7,1,3]},{'Mconv2_stage%d_L1'%i:[128,128,7,1,3]},{'Mconv3_stage%d_L1'%i:[128,128,7,1,3]},{'Mconv4_stage%d_L1'%i:[128,128,7,1,3]},
 {'Mconv5_stage%d_L1'%i:[128,128,7,1,3]},{'Mconv6_stage%d_L1'%i:[128,128,1,1,0]},{'Mconv7_stage%d_L1'%i:[128,38,1,1,0]}]
     blocks['block%d_2'%i]  = [{'Mconv1_stage%d_L2'%i:[185,128,7,1,3]},{'Mconv2_stage%d_L2'%i:[128,128,7,1,3]},{'Mconv3_stage%d_L2'%i:[128,128,7,1,3]},{'Mconv4_stage%d_L2'%i:[128,128,7,1,3]},
 {'Mconv5_stage%d_L2'%i:[128,128,7,1,3]},{'Mconv6_stage%d_L2'%i:[128,128,1,1,0]},{'Mconv7_stage%d_L2'%i:[128,19,1,1,0]}]

 def make_layers(cfg_dict):
     layers = []
     for i in range(len(cfg_dict)-1):
         one_ = cfg_dict[i]
         for k,v in one_.iteritems():
             if 'pool' in k:
                 layers += [nn.MaxPool2d(kernel_size=v[0], stride=v[1], padding=v[2] )]
             else:
                 conv2d = nn.Conv2d(in_channels=v[0], out_channels=v[1], kernel_size=v[2], stride = v[3], padding=v[4])
                 layers += [conv2d, nn.ReLU(inplace=True)]
     one_ = cfg_dict[-1].keys()
     k = one_[0]
     v = cfg_dict[-1][k]
     conv2d = nn.Conv2d(in_channels=v[0], out_channels=v[1], kernel_size=v[2], stride = v[3], padding=v[4])
     layers += [conv2d]
     return nn.Sequential(*layers)

 layers = []
 for i in range(len(block0)):
     one_ = block0[i]
     for k,v in one_.iteritems():
         if 'pool' in k:
             layers += [nn.MaxPool2d(kernel_size=v[0], stride=v[1], padding=v[2] )]
         else:
             conv2d = nn.Conv2d(in_channels=v[0], out_channels=v[1], kernel_size=v[2], stride = v[3], padding=v[4])
             layers += [conv2d, nn.ReLU(inplace=True)]  

 models = {}
 models['block0']=nn.Sequential(*layers)        

 for k,v in blocks.iteritems():
     models[k] = make_layers(v)

 class pose_model(nn.Module):
     def __init__(self,model_dict,transform_input=False):
         super(pose_model, self).__init__()
         self.model0   = model_dict['block0']
         self.model1_1 = model_dict['block1_1']
         self.model2_1 = model_dict['block2_1']
         self.model3_1 = model_dict['block3_1']
         self.model4_1 = model_dict['block4_1']
         self.model5_1 = model_dict['block5_1']
         self.model6_1 = model_dict['block6_1']  

         self.model1_2 = model_dict['block1_2']
         self.model2_2 = model_dict['block2_2']
         self.model3_2 = model_dict['block3_2']
         self.model4_2 = model_dict['block4_2']
         self.model5_2 = model_dict['block5_2']
         self.model6_2 = model_dict['block6_2']

     def forward(self, x):
         out1 = self.model0(x)

         out1_1 = self.model1_1(out1)
         out1_2 = self.model1_2(out1)
         out2  = torch.cat([out1_1,out1_2,out1],1)

         out2_1 = self.model2_1(out2)
         out2_2 = self.model2_2(out2)
         out3   = torch.cat([out2_1,out2_2,out1],1)

         out3_1 = self.model3_1(out3)
         out3_2 = self.model3_2(out3)
         out4   = torch.cat([out3_1,out3_2,out1],1)

         out4_1 = self.model4_1(out4)
         out4_2 = self.model4_2(out4)
         out5   = torch.cat([out4_1,out4_2,out1],1)  

         out5_1 = self.model5_1(out5)
         out5_2 = self.model5_2(out5)
         out6   = torch.cat([out5_1,out5_2,out1],1)         

         out6_1 = self.model6_1(out6)
         out6_2 = self.model6_2(out6)

         return out6_1,out6_2        

 model = pose_model(models)
 model.load_state_dict(torch.load(weight_name))
 model.cuda()
 model.float()
 model.eval()

 param_, model_ = config_reader()

 #torch.nn.functional.pad(img pad, mode='constant', value=model_['padValue'])
 tic = time.time()
 test_image = './sample_image/ski.jpg'
 #test_image = 'a.jpg'
 oriImg = cv2.imread(test_image) # B,G,R order
 imageToTest = Variable(T.transpose(T.transpose(T.unsqueeze(torch.from_numpy(oriImg).float(),0),2,3),1,2),volatile=True).cuda()

 multiplier = [x * model_['boxsize'] / oriImg.shape[0] for x in param_['scale_search']] # 不同scale输入

 heatmap_avg = torch.zeros((len(multiplier),19,oriImg.shape[0], oriImg.shape[1])).cuda()
 paf_avg = torch.zeros((len(multiplier),38,oriImg.shape[0], oriImg.shape[1])).cuda()
 #print heatmap_avg.size()

 toc =time.time()
 print 'time is %.5f'%(toc-tic)
 tic = time.time()
 for m in range(len(multiplier)):
     scale = multiplier[m]
     h = int(oriImg.shape[0]*scale)
     w = int(oriImg.shape[1]*scale)
     pad_h = 0 if (h%model_['stride']==0) else model_['stride'] - (h % model_['stride'])
     pad_w = 0 if (w%model_['stride']==0) else model_['stride'] - (w % model_['stride'])
     new_h = h+pad_h
     new_w = w+pad_w

     imageToTest = cv2.resize(oriImg, (0,0), fx=scale, fy=scale, interpolation=cv2.INTER_CUBIC)
     imageToTest_padded, pad = util.padRightDownCorner(imageToTest, model_['stride'], model_['padValue'])
     imageToTest_padded = np.transpose(np.float32(imageToTest_padded[:,:,:,np.newaxis]), (3,2,0,1))/256 - 0.5
     # (-0.5~0.5)
     feed = Variable(T.from_numpy(imageToTest_padded)).cuda()
     output1,output2 = model(feed)
     print output1.size()
     print output2.size()
     heatmap = nn.UpsamplingBilinear2d((oriImg.shape[0], oriImg.shape[1])).cuda()(output2) # 对output上采样至原图大小

     paf = nn.UpsamplingBilinear2d((oriImg.shape[0], oriImg.shape[1])).cuda()(output1)     # 同理

     heatmap_avg[m] = heatmap[0].data
     paf_avg[m] = paf[0].data  

 toc =time.time()
 print 'time is %.5f'%(toc-tic)
 tic = time.time()
 # 不同scale的heatmap和PAF取均值
 heatmap_avg = T.transpose(T.transpose(T.squeeze(T.mean(heatmap_avg, 0)),0,1),1,2).cuda()
 paf_avg     = T.transpose(T.transpose(T.squeeze(T.mean(paf_avg, 0)),0,1),1,2).cuda()
 heatmap_avg=heatmap_avg.cpu().numpy()
 paf_avg    = paf_avg.cpu().numpy()
 toc =time.time()
 print 'time is %.5f'%(toc-tic)
 tic = time.time()

 all_peaks = []
 peak_counter = 0

 #maps =
 # picture array is reversed
 for part in range(18): # 18个关节点的featuremap
     map_ori = heatmap_avg[:,:,part]
     map = gaussian_filter(map_ori, sigma=3)

     map_left = np.zeros(map.shape)
     map_left[1:,:] = map[:-1,:]
     map_right = np.zeros(map.shape)
     map_right[:-1,:] = map[1:,:]
     map_up = np.zeros(map.shape)
     map_up[:,1:] = map[:,:-1]
     map_down = np.zeros(map.shape)
     map_down[:,:-1] = map[:,1:]

     # 计算是否为局部极值
     peaks_binary = np.logical_and.reduce((map>=map_left, map>=map_right, map>=map_up, map>=map_down, map > param_['thre1']))
 #    peaks_binary = T.eq(
 #    peaks = zip(T.nonzero(peaks_binary)[0],T.nonzero(peaks_binary)[0])

     peaks = zip(np.nonzero(peaks_binary)[1], np.nonzero(peaks_binary)[0]) # note reverse

     peaks_with_score = [x + (map_ori[x[1],x[0]],) for x in peaks]
     id = range(peak_counter, peak_counter + len(peaks))
     peaks_with_score_and_id = [peaks_with_score[i] + (id[i],) for i in range(len(id))]

     all_peaks.append(peaks_with_score_and_id) # 一个关节点featuremap上不同人的peak [[y, x, peak_score, id)],...]
     peak_counter += len(peaks)

 # 计算线性积分 采样10个点计算
 connection_all = []
 special_k = []
 mid_num = 10

 for k in range(len(mapIdx)):
     score_mid = paf_avg[:,:,[x-19 for x in mapIdx[k]]] # channel为2的paf_avg,表示PAF向量
     candA = all_peaks[limbSeq[k][0]-1]  #第k个limb中左关节点的候选集合A(不同人的关节点)
     candB = all_peaks[limbSeq[k][1]-1]  #第k个limb中右关节点的候选集合B(不同人的关节点)
     nA = len(candA)
     nB = len(candB)
     # indexA, indexB = limbSeq[k]
     if(nA != 0 and nB != 0): # 有候选时开始连接
         connection_candidate = []
         for i in range(nA):
             for j in range(nB):
                 vec = np.subtract(candB[j][:2], candA[i][:2])
                 norm = math.sqrt(vec[0]*vec[0] + vec[1]*vec[1])
                 vec = np.divide(vec, norm)  # 计算单位向量

                 startend = zip(np.linspace(candA[i][0], candB[j][0], num=mid_num), \
                                np.linspace(candA[i][1], candB[j][1], num=mid_num)) # 在A[i],B[j]连接线上采样mid_num个点

                 # 计算采样点的PAF向量
                 vec_x = np.array([score_mid[int(round(startend[I][1])), int(round(startend[I][0])), 0] \
                                   for I in range(len(startend))])
                 vec_y = np.array([score_mid[int(round(startend[I][1])), int(round(startend[I][0])), 1] \
                                   for I in range(len(startend))])

                 # 采样点的PAF向量与limb的单位向量计算余弦相似度score,内积
                 score_midpts = np.multiply(vec_x, vec[0]) + np.multiply(vec_y, vec[1])
                 score_with_dist_prior = sum(score_midpts)/len(score_midpts) + min(0.5*oriImg.shape[0]/norm-1, 0)
                 criterion1 = len(np.nonzero(score_midpts > param_['thre2'])[0]) > 0.8 * len(score_midpts)
                 criterion2 = score_with_dist_prior > 0
                 if criterion1 and criterion2:
                     # (i,j,score,score_all)
                     connection_candidate.append([i, j, score_with_dist_prior, score_with_dist_prior+candA[i][2]+candB[j][2]])

         connection_candidate = sorted(connection_candidate, key=lambda x: x[2], reverse=True) # 按score排序
         connection = np.zeros((0,5))
         for c in range(len(connection_candidate)):
             i,j,s = connection_candidate[c][0:3]
             if(i not in connection[:,3] and j not in connection[:,4]):
                 connection = np.vstack([connection, [candA[i][3], candB[j][3], s, i, j]]) # A_id, B_id, score, i, j
                 if(len(connection) >= min(nA, nB)):
                     break

         connection_all.append(connection) # 多个符合当前limb的组合 [[A_id, B_id, score, i, j],...]
     else:
         special_k.append(k)
         connection_all.append([])

 '''
 function: 关节点连成每个人的limb
 subset: last number in each row is the total parts number of that person
 subset: the second last number in each row is the score of the overall configuration
 candidate: 候选关节点
 connection_all: 候选limb

 '''
 subset = -1 * np.ones((0, 20))
 candidate = np.array([item for sublist in all_peaks for item in sublist])  # 一个id的(y,x,score,id)(关节点)

 for k in range(len(mapIdx)):
     if k not in special_k:
         partAs = connection_all[k][:,0]  # 第k个limb,左端点的候选id集合
         partBs = connection_all[k][:,1]  # 第k个limb,右端点的候选id集合
         indexA, indexB = np.array(limbSeq[k]) - 1 # 关节点index

         for i in range(len(connection_all[k])): #= 1:size(temp,1)
             found = 0
             subset_idx = [-1, -1]
             for j in range(len(subset)): #1:size(subset,1): 遍历subset里每个人,看当前两个关节点出现过几次
                 if subset[j][indexA] == partAs[i] or subset[j][indexB] == partBs[i]:
                     subset_idx[found] = j
                     found += 1

             if found == 1: # 在这个人的subset里连上这个limb
                 j = subset_idx[0]
                 if(subset[j][indexB] != partBs[i]):
                     subset[j][indexB] = partBs[i]
                     subset[j][-1] += 1
                     subset[j][-2] += candidate[partBs[i].astype(int), 2] + connection_all[k][i][2]
                 elif(subset[j][indexA] != partAs[i]):
                     subset[j][indexA] = partAs[i]
                     subset[j][-1] += 1
                     subset[j][-2] += candidate[partAs[i].astype(int), 2] + connection_all[k][i][2]

             elif found == 2: # if found 2 and disjoint, merge them
                 j1, j2 = subset_idx
                 print "found = 2"
                 membership = ((subset[j1]>=0).astype(int) + (subset[j2]>=0).astype(int))[:-2]
                 if len(np.nonzero(membership == 2)[0]) == 0:
                     # 如果两个人的相同关节点没有在各自的subset中都连成limb,那么合并两个subset构成一个人
                     subset[j1][:-2] += (subset[j2][:-2] + 1)
                     subset[j1][-2:] += subset[j2][-2:]
                     subset[j1][-2] += connection_all[k][i][2]
                     subset = np.delete(subset, j2, 0)
                 # To-Do 这里有问题, 怎么合并才对?
                 # else: # as like found == 1
                 #     subset[j1][indexB] = partBs[i]
                 #     subset[j1][-1] += 1
                 #     subset[j1][-2] += candidate[partBs[i].astype(int), 2] + connection_all[k][i][2]

             # if find no partA in the subset, create a new subset
             elif not found and k < 17:
                 row = -1 * np.ones(20)
                 row[indexA] = partAs[i]
                 row[indexB] = partBs[i]
                 row[-1] = 2
                 row[-2] = sum(candidate[connection_all[k][i,:2].astype(int), 2]) + connection_all[k][i][2]
                 subset = np.vstack([subset, row])

 # delete some rows of subset which has few parts occur
 deleteIdx = [];
 for i in range(len(subset)):
     if subset[i][-1] < 4 or subset[i][-2]/subset[i][-1] < 0.4:
         deleteIdx.append(i)
 subset = np.delete(subset, deleteIdx, axis=0)

 canvas = cv2.imread(test_image) # B,G,R order
 for i in range(18):
     for j in range(len(all_peaks[i])):
         cv2.circle(canvas, all_peaks[i][j][0:2], 4, colors[i], thickness=-1)

 stickwidth = 4

 for i in range(17):
     for n in range(len(subset)):
         index = subset[n][np.array(limbSeq[i])-1] # limb的两个关节点index
         if -1 in index:
             continue
         cur_canvas = canvas.copy()
         Y = candidate[index.astype(int), 0] # 两个index点的纵坐标
         X = candidate[index.astype(int), 1] # 两个index点的横坐标
         mX = np.mean(X)
         mY = np.mean(Y)
         length = ((X[0] - X[1]) ** 2 + (Y[0] - Y[1]) ** 2) ** 0.5
         angle = math.degrees(math.atan2(X[0] - X[1], Y[0] - Y[1]))
         polygon = cv2.ellipse2Poly((int(mY),int(mX)), (int(length/2), stickwidth), int(angle), 0, 360, 1)
         cv2.fillConvexPoly(cur_canvas, polygon, colors[i])
         canvas = cv2.addWeighted(canvas, 0.4, cur_canvas, 0.6, 0)

 #Parallel(n_jobs=1)(delayed(handle_one)(i) for i in range(18))

 toc =time.time()
 print 'time is %.5f'%(toc-tic)
 cv2.imwrite('result.png',canvas)