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pytorch建立mobilenetV3-ssd网络进行训练与预测
这篇文章记录的是我在公司实习用深度学习做车辆信息识别项目时,用来做车辆检测的算法。
因为我们公司面向的边缘端计算,边缘盒子的计算能力有限,所以我们在做算法研究时,就尽量选用轻量级算法,所以目标检测算法用mobilenetV3-ssd,这是一个精度能达到很高,权值很小的算法,我比较喜欢。
Step1:搭建mobilenetV3-ssd网络框架
它的网络原理很简单,就是把传统的ssd算法里面的VGG网络换成了mobilenetV3,其他的都一样。
需要提前准备的函数和类
在真的写网络框架之前,我们需要把网络中需要调用的一些激活函数和卷积块先写好。
先是mobilenetV3需要调用的两个激活函数,一个注意力模型SeModule,和卷积块Block。
class hswish(nn.Module): def forward(self, x): out = x * F.relu6(x + float(3.0), inplace=True) / float(6.0) return out class hsigmoid(nn.Module): def forward(self, x): out = F.relu6(x + float(3.0), inplace=True) / float(6.0) return out class SeModule(nn.Module): def __init__(self, in_size, reduction=4): super(SeModule, self).__init__() self.avg_pool = nn.AdaptiveAvgPool2d(1) self.se = nn.Sequential( nn.Conv2d(in_size, in_size // reduction, kernel_size=1, stride=1, padding=0, bias=False), nn.BatchNorm2d(in_size // reduction), nn.ReLU(inplace=True), nn.Conv2d(in_size // reduction, in_size, kernel_size=1, stride=1, padding=0, bias=False), nn.BatchNorm2d(in_size), hsigmoid() ) def forward(self, x): return x * self.se(x) class Block(nn.Module): def __init__(self, kernel_size, in_size, expand_size, out_size, nolinear, semodule, stride): super(Block, self).__init__() self.stride = stride self.se = semodule self.output_status = False if kernel_size == 5 and in_size == 160 and expand_size == 672: self.output_status = True self.conv1 = nn.Conv2d(in_size, expand_size, kernel_size=1, stride=1, padding=0, bias=False) self.bn1 = nn.BatchNorm2d(expand_size) self.nolinear1 = nolinear self.conv2 = nn.Conv2d(expand_size, expand_size, kernel_size=kernel_size, stride=stride, padding=kernel_size//2, groups=expand_size, bias=False) self.bn2 = nn.BatchNorm2d(expand_size) self.nolinear2 = nolinear self.conv3 = nn.Conv2d(expand_size, out_size, kernel_size=1, stride=1, padding=0, bias=False) self.bn3 = nn.BatchNorm2d(out_size) self.shortcut = nn.Sequential() if stride == 1 and in_size != out_size: self.shortcut = nn.Sequential( nn.Conv2d(in_size, out_size, kernel_size=1, stride=1, padding=0, bias=False), nn.BatchNorm2d(out_size), ) def forward(self, x): out = self.nolinear1(self.bn1(self.conv1(x))) if self.output_status: expand = out out = self.nolinear2(self.bn2(self.conv2(out))) out = self.bn3(self.conv3(out)) if self.se != None: out = self.se(out) out = out + self.shortcut(x) if self.stride==1 else out if self.output_status: return (expand, out) return out
然后是ssd网络需要调用的卷积块。
def conv_bn(inp, oup, stride, groups=1, activation=nn.ReLU6): return nn.Sequential( nn.Conv2d(inp, oup, 3, stride, 1, bias=False, groups=groups), nn.BatchNorm2d(oup), activation(inplace=True) ) def conv_1x1_bn(inp, oup, groups=1, activation=nn.ReLU6): return nn.Sequential( nn.Conv2d(inp, oup, 1, 1, 0, bias=False, groups=groups), nn.BatchNorm2d(oup), activation(inplace=True) ) class AuxiliaryConvolutions(nn.Module): """ 辅助卷积层 """ def __init__(self): super(AuxiliaryConvolutions, self).__init__() self.extra_convs = [] self.extra_convs.append(conv_1x1_bn(960, 256)) self.extra_convs.append(conv_bn(256, 256, 2, groups=256)) self.extra_convs.append(conv_1x1_bn(256, 512, groups=1)) self.extra_convs.append(conv_1x1_bn(512, 128)) self.extra_convs.append(conv_bn(128, 128, 2, groups=128)) self.extra_convs.append(conv_1x1_bn(128, 256)) self.extra_convs.append(conv_1x1_bn(256, 128)) self.extra_convs.append(conv_bn(128, 128, 2, groups=128)) self.extra_convs.append(conv_1x1_bn(128, 256)) self.extra_convs.append(conv_1x1_bn(256, 64)) self.extra_convs.append(conv_bn(64, 64, 2, groups=64)) self.extra_convs.append(conv_1x1_bn(64, 128)) self.extra_convs = nn.Sequential(*self.extra_convs) self.init_conv2d() def init_conv2d(self): for m in self.modules(): if isinstance(m, nn.Conv2d): init.kaiming_normal_(m.weight, mode='fan_out') if m.bias is not None: init.constant_(m.bias, 0) elif isinstance(m, nn.BatchNorm2d): init.constant_(m.weight, 1) init.constant_(m.bias, 0) elif isinstance(m, nn.Linear): init.normal_(m.weight, std=0.001) if m.bias is not None: init.constant_(m.bias, 0) def forward(self, conv7_feats): """ Forward propagation. :param conv7_feats: lower-level conv7 feature map :return: higher-level feature maps conv8_2, conv9_2, conv10_2, and conv11_2 """ outs = [] out=conv7_feats for i, conv in enumerate(self.extra_convs): out = conv(out) if i % 3 == 2: outs.append(out) conv8_2_feats=outs[0] conv9_2_feats=outs[1] conv10_2_feats=outs[2] conv11_2_feats=outs[3] return conv8_2_feats, conv9_2_feats, conv10_2_feats, conv11_2_feats class PredictionConvolutions(nn.Module): def __init__(self, n_classes): """ 预测卷积层 """ super(PredictionConvolutions, self).__init__() self.n_classes = n_classes n_boxes = {'conv4_3': 4, 'conv7': 6, 'conv8_2': 6, 'conv9_2': 6, 'conv10_2': 6, 'conv11_2': 6} input_channels=[672, 960, 512, 256, 256, 128] self.loc_conv4_3 = nn.Conv2d(input_channels[0], n_boxes['conv4_3'] * 4, kernel_size=3, padding=1) self.loc_conv7 = nn.Conv2d(input_channels[1], n_boxes['conv7'] * 4, kernel_size=3, padding=1) self.loc_conv8_2 = nn.Conv2d(input_channels[2], n_boxes['conv8_2'] * 4, kernel_size=3, padding=1) self.loc_conv9_2 = nn.Conv2d(input_channels[3], n_boxes['conv9_2'] * 4, kernel_size=3, padding=1) self.loc_conv10_2 = nn.Conv2d(input_channels[4], n_boxes['conv10_2'] * 4, kernel_size=3, padding=1) self.loc_conv11_2 = nn.Conv2d(input_channels[5], n_boxes['conv11_2'] * 4, kernel_size=3, padding=1) self.cl_conv4_3 = nn.Conv2d(input_channels[0], n_boxes['conv4_3'] * n_classes, kernel_size=3, padding=1) self.cl_conv7 = nn.Conv2d(input_channels[1], n_boxes['conv7'] * n_classes, kernel_size=3, padding=1) self.cl_conv8_2 = nn.Conv2d(input_channels[2], n_boxes['conv8_2'] * n_classes, kernel_size=3, padding=1) self.cl_conv9_2 = nn.Conv2d(input_channels[3], n_boxes['conv9_2'] * n_classes, kernel_size=3, padding=1) self.cl_conv10_2 = nn.Conv2d(input_channels[4], n_boxes['conv10_2'] * n_classes, kernel_size=3, padding=1) self.cl_conv11_2 = nn.Conv2d(input_channels[5], n_boxes['conv11_2'] * n_classes, kernel_size=3, padding=1) self.init_conv2d() def init_conv2d(self): """ Initialize convolution parameters. """ for c in self.children(): if isinstance(c, nn.Conv2d): nn.init.xavier_uniform_(c.weight) nn.init.constant_(c.bias, 0.) def forward(self, conv4_3_feats, conv7_feats, conv8_2_feats, conv9_2_feats, conv10_2_feats, conv11_2_feats): batch_size = conv4_3_feats.size(0) l_conv4_3 = self.loc_conv4_3(conv4_3_feats) l_conv4_3 = l_conv4_3.permute(0, 2, 3, 1).contiguous() l_conv4_3 = l_conv4_3.view(batch_size, -1, 4) l_conv7 = self.loc_conv7(conv7_feats) l_conv7 = l_conv7.permute(0, 2, 3, 1).contiguous() l_conv7 = l_conv7.view(batch_size, -1, 4) l_conv8_2 = self.loc_conv8_2(conv8_2_feats) l_conv8_2 = l_conv8_2.permute(0, 2, 3, 1).contiguous() l_conv8_2 = l_conv8_2.view(batch_size, -1, 4) l_conv9_2 = self.loc_conv9_2(conv9_2_feats) l_conv9_2 = l_conv9_2.permute(0, 2, 3, 1).contiguous() l_conv9_2 = l_conv9_2.view(batch_size, -1, 4) l_conv10_2 = self.loc_conv10_2(conv10_2_feats) l_conv10_2 = l_conv10_2.permute(0, 2, 3, 1).contiguous() l_conv10_2 = l_conv10_2.view(batch_size, -1, 4) l_conv11_2 = self.loc_conv11_2(conv11_2_feats) l_conv11_2 = l_conv11_2.permute(0, 2, 3, 1).contiguous() l_conv11_2 = l_conv11_2.view(batch_size, -1, 4) c_conv4_3 = self.cl_conv4_3(conv4_3_feats) c_conv4_3 = c_conv4_3.permute(0, 2, 3, 1).contiguous() c_conv4_3 = c_conv4_3.view(batch_size, -1,self.n_classes) c_conv7 = self.cl_conv7(conv7_feats) c_conv7 = c_conv7.permute(0, 2, 3, 1).contiguous() c_conv7 = c_conv7.view(batch_size, -1,self.n_classes) c_conv8_2 = self.cl_conv8_2(conv8_2_feats) c_conv8_2 = c_conv8_2.permute(0, 2, 3, 1).contiguous() c_conv8_2 = c_conv8_2.view(batch_size, -1, self.n_classes) c_conv9_2 = self.cl_conv9_2(conv9_2_feats) c_conv9_2 = c_conv9_2.permute(0, 2, 3, 1).contiguous() c_conv9_2 = c_conv9_2.view(batch_size, -1, self.n_classes) c_conv10_2 = self.cl_conv10_2(conv10_2_feats) c_conv10_2 = c_conv10_2.permute(0, 2, 3, 1).contiguous() c_conv10_2 = c_conv10_2.view(batch_size, -1, self.n_classes) c_conv11_2 = self.cl_conv11_2(conv11_2_feats) c_conv11_2 = c_conv11_2.permute(0, 2, 3, 1).contiguous() c_conv11_2 = c_conv11_2.view(batch_size, -1, self.n_classes) locs = torch.cat([l_conv4_3, l_conv7, l_conv8_2, l_conv9_2, l_conv10_2, l_conv11_2], dim=1) classes_scores = torch.cat([c_conv4_3, c_conv7, c_conv8_2, c_conv9_2, c_conv10_2, c_conv11_2],dim=1) return locs, classes_scores
mobilenetV3_large
class MobileNetV3_Large(nn.Module): def __init__(self, num_classes=1000): super(MobileNetV3_Large, self).__init__() self.conv1 = nn.Conv2d(3, 16, kernel_size=3, stride=2, padding=1, bias=False) self.bn1 = nn.BatchNorm2d(16) self.hs1 = hswish() self.bneck = nn.Sequential( Block(3, 16, 16, 16, nn.ReLU(inplace=True), None, 1), Block(3, 16, 64, 24, nn.ReLU(inplace=True), None, 2), Block(3, 24, 72, 24, nn.ReLU(inplace=True), None, 1), Block(5, 24, 72, 40, nn.ReLU(inplace=True), SeModule(40), 2), Block(5, 40, 120, 40, nn.ReLU(inplace=True), SeModule(40), 1), Block(5, 40, 120, 40, nn.ReLU(inplace=True), SeModule(40), 1), Block(3, 40, 240, 80, hswish(), None, 2), Block(3, 80, 200, 80, hswish(), None, 1), Block(3, 80, 184, 80, hswish(), None, 1), Block(3, 80, 184, 80, hswish(), None, 1), Block(3, 80, 480, 112, hswish(), SeModule(112), 1), Block(3, 112, 672, 112, hswish(), SeModule(112), 1), Block(5, 112, 672, 160, hswish(), SeModule(160), 1), Block(5, 160, 672, 160, hswish(), SeModule(160), 2), Block(5, 160, 960, 160, hswish(), SeModule(160), 1), ) self.conv2 = nn.Conv2d(160, 960, kernel_size=1, stride=1, padding=0, bias=False) self.bn2 = nn.BatchNorm2d(960) self.hs2 = hswish() self.linear3 = nn.Linear(960, 1280) self.bn3 = nn.BatchNorm1d(1280) self.hs3 = hswish() self.linear4 = nn.Linear(1280, 1000) self.init_weights() #这个是加载预训练权值或初始化权值 # def load_pretrained_layers(self,pretrained): # pretrained_state_dict = torch.load(pretrained) # self.load_state_dict(pretrained_state_dict) # for param in self.parameters(): # param.requires_grad = False # print("\nLoaded base model.\n") def init_weights(self, pretrained=None):#如果不用预训练权值,把pretrained设为None就行 if isinstance(pretrained, str): #判断一个对象是否是一个已知类型 checkpoint = torch.load(pretrained,map_location='cpu') ["state_dict"] self.load_state_dict(checkpoint,strict=False) for param in self.parameters(): param.requires_grad = True # to be or not to be # also load module # if isinstance(checkpoint, OrderedDict): # state_dict = checkpoint # elif isinstance(checkpoint, dict) and 'state_dict' in checkpoint: # state_dict = checkpoint['state_dict'] # else: # print("No state_dict found in checkpoint file") # if list(state_dict.keys())[0].startswith('module.'): # state_dict = {k[7:]: v for k, v in checkpoint['state_dict'].items()} # # load state_dict # if hasattr(self, 'module'): # self.module.load_state_dict( state_dict,strict=False) # else: # self.load_state_dict(state_dict,strict=False) print("\nLoaded base model.\n") elif pretrained is None: print("\nNo loaded base model.\n") for m in self.modules(): #self.modules()里面存储了net的所有模块。 if isinstance(m, nn.Conv2d): init.kaiming_normal_(m.weight, mode='fan_out') #用kaiming正态分布进行初始化。 if m.bias is not None: init.constant_(m.bias, 0) elif isinstance(m, nn.BatchNorm2d): init.constant_(m.weight, 1) init.constant_(m.bias, 0) elif isinstance(m, nn.Linear): init.normal_(m.weight, std=0.001) if m.bias is not None: init.constant_(m.bias, 0) def forward(self, x): out = self.hs1(self.bn1(self.conv1(x))) for i, block in enumerate(self.bneck): out = block(out) if isinstance(out, tuple): conv4_3_feats =out[0] out = out[1] out = self.hs2(self.bn2(self.conv2(out))) conv7_feats=out return conv4_3_feats,conv7_feats
调用mobilenetV3的ssd网络
class SSD300(nn.Module): """ The SSD300 network - encapsulates the base MobileNet network, auxiliary, and prediction convolutions. """ def __init__(self, n_classes): super(SSD300, self).__init__() self.n_classes = n_classes self.base = MobileNetV3_Large(num_classes=self.n_classes) self.aux_convs = AuxiliaryConvolutions() self.pred_convs = PredictionConvolutions(n_classes) self.rescale_factors = nn.Parameter(torch.FloatTensor(1, 672, 1, 1)) nn.init.constant_(self.rescale_factors, 20) self.priors_cxcy = self.create_prior_boxes() #这是在初始化先验框? def forward(self, image): conv4_3_feats, conv7_feats = self.base(image) norm = conv4_3_feats.pow(2).sum(dim=1, keepdim=True).sqrt()+1e-10 conv4_3_feats = conv4_3_feats / norm conv4_3_feats = conv4_3_feats * self.rescale_factors conv8_2_feats, conv9_2_feats, conv10_2_feats, conv11_2_feats = self.aux_convs(conv7_feats) locs, classes_scores = self.pred_convs(conv4_3_feats, conv7_feats, conv8_2_feats, conv9_2_feats, conv10_2_feats,conv11_2_feats) return locs, classes_scores def create_prior_boxes(self): fmap_dims = {'conv4_3': 19, 'conv7': 10, 'conv8_2': 5, 'conv9_2': 3, 'conv10_2': 2, 'conv11_2': 1} obj_scales = {'conv4_3': 0.1, 'conv7': 0.2, 'conv8_2': 0.375, 'conv9_2': 0.55, 'conv10_2': 0.725, 'conv11_2': 0.9} aspect_ratios = {'conv4_3': [1., 2., 0.5], 'conv7': [1., 2., 3., 0.5, .333], 'conv8_2': [1., 2., 3., 0.5, .333], 'conv9_2': [1., 2., 3., 0.5, .333], 'conv10_2': [1., 2., 3., 0.5, .333], 'conv11_2': [1., 2., 3., 0.5, .333]} fmaps = list(fmap_dims.keys()) prior_boxes = [] for k, fmap in enumerate(fmaps): for i in range(fmap_dims[fmap]): for j in range(fmap_dims[fmap]): cx = (j + 0.5) / fmap_dims[fmap] cy = (i + 0.5) / fmap_dims[fmap] for ratio in aspect_ratios[fmap]: prior_boxes.append([cx, cy, obj_scales[fmap] * sqrt(ratio), obj_scales[fmap] / sqrt(ratio)]) if ratio == 1.: try: additional_scale = sqrt(obj_scales[fmap] * obj_scales[fmaps[k + 1]]) except IndexError: additional_scale = 1. prior_boxes.append([cx, cy, additional_scale, additional_scale]) prior_boxes = torch.FloatTensor(prior_boxes).to(device) prior_boxes.clamp_(0, 1) return prior_boxes def detect_objects(self, predicted_locs, predicted_scores, min_score, max_overlap, top_k): """ For each class, perform Non-Maximum Suppression (NMS) on boxes that are above a minimum threshold. :param min_score: minimum threshold for a box to be considered a match for a certain class :param max_overlap: maximum overlap two boxes can have so that the one with the lower score is not suppressed via NMS :param top_k: if there are a lot of resulting detection across all classes, keep only the top 'k' :return: detections (boxes, labels, and scores), lists of length batch_size """ batch_size = predicted_locs.size(0) n_priors = self.priors_cxcy.size(0) predicted_scores = F.softmax(predicted_scores, dim=2) all_images_boxes = list() all_images_labels = list() all_images_scores = list() assert n_priors == predicted_locs.size(1) == predicted_scores.size(1) for i in range(batch_size): decoded_locs = cxcy_to_xy( gcxgcy_to_cxcy(predicted_locs[i], self.priors_cxcy)) image_boxes = list() image_labels = list() image_scores = list() max_scores, best_label = predicted_scores[i].max(dim=1) for c in range(1, self.n_classes): class_scores = predicted_scores[i][:, c] score_above_min_score = class_scores > min_score n_above_min_score = score_above_min_score.sum().item() if n_above_min_score == 0: continue class_scores = class_scores[score_above_min_score] class_decoded_locs = decoded_locs[score_above_min_score] class_scores, sort_ind = class_scores.sort(dim=0, descending=True) class_decoded_locs = class_decoded_locs[sort_ind] overlap = find_jaccard_overlap(class_decoded_locs, class_decoded_locs) suppress = torch.zeros((n_above_min_score), dtype=torch.bool).to(device) for box in range(class_decoded_locs.size(0)): if suppress[box] == 1: continue suppress = torch.max(suppress, overlap[box] > max_overlap) suppress[box] = 0 image_boxes.append(class_decoded_locs[~suppress]) image_labels.append(torch.LongTensor((~ suppress).sum().item() * [c]).to(device)) image_scores.append(class_scores[~suppress]) if len(image_boxes) == 0: image_boxes.append(torch.FloatTensor([[0., 0., 1., 1.]]).to(device)) image_labels.append(torch.LongTensor([0]).to(device)) image_scores.append(torch.FloatTensor([0.]).to(device)) image_boxes = torch.cat(image_boxes, dim=0) image_labels = torch.cat(image_labels, dim=0) image_scores = torch.cat(image_scores, dim=0) n_objects = image_scores.size(0) if n_objects > top_k: image_scores, sort_ind = image_scores.sort(dim=0, descending=True) image_scores = image_scores[:top_k] image_boxes = image_boxes[sort_ind][:top_k] image_labels = image_labels[sort_ind][:top_k] all_images_boxes.append(image_boxes) all_images_labels.append(image_labels) all_images_scores.append(image_scores) return all_images_boxes, all_images_labels, all_images_scores
Step2:训练
关键在于训练,这里会利用pytorch的语法规则进行训练。
训练数据预处理(VOC形式的dbb数据)
本来是想在这写用VOC2007进行训练,但是后来想想,人总是要进步嘛,不能总是利用VOC官方给的数据训练吧,所以这里还是清楚的讲一下怎么将dbb数据转换成VOC格式,并且进行训练。
首先,去官网下载dbb数据。
然后,利用下面这个程序,将json格式的标注文件装换成xml格式的标注文件。
import os from json import loads from dicttoxml import dicttoxml from xml.dom.minidom import parseString def jsonToXml(json_path, xml_path): #@abstract: transfer json file to xml file #json_path: complete path of the json file #xml_path: complete path of the xml file with open(json_path,'r',encoding='UTF-8')as json_file: load_dict=loads(json_file.read()) #print(load_dict) my_item_func = lambda x: 'Annotation' xml = dicttoxml(load_dict,custom_root='Annotations',item_func=my_item_func,attr_type=False) dom = parseString(xml) #print(dom.toprettyxml()) #print(type(dom.toprettyxml())) with open(xml_path,'w',encoding='UTF-8')as xml_file: xml_file.write(dom.toprettyxml()) def json_to_xml(json_dir, xml_dir): #transfer all json file which in the json_dir to xml_dir if(os.path.exists(xml_dir)==False): #如果没有这个文件夹,就生成这个文件夹 os.makedirs(xml_dir) dir = os.listdir(json_dir) i=0 for file in dir: file_list=file.split(".") if(file_list[-1] == 'json'): jsonToXml(os.path.join(json_dir,file),os.path.join(xml_dir,file_list[0]+'.xml')) i=i+1 print('处理了第:',i,'个') if __name__ == '__main__': #transfer multi files j_dir = "train" #存放json文件的文件夹路径 x_dir = "train_xml" #存放xml文件的文件夹路径,里面不需要有文件 json_to_xml(j_dir, x_dir)
然后,利用下面这个程序,生成ImageSets/main里面的train.txt文件。
import os import random trainval_percent = 0.7 # 可以自己设置 train_percent = 0.8 # 可以自己设置 xmlfilepath = f"Annotations" # 地址填自己的 txtsavepath = f"ImageSets/Main" total_xml = os.listdir(xmlfilepath) num = len(total_xml) list = range(num) tv = int(num * trainval_percent) tr = int(tv * train_percent) trainval = random.sample(list, tv) train = random.sample(trainval, tr) ftrainval = open(txtsavepath + '/trainval.txt', 'w') ftest = open(txtsavepath + '/test.txt', 'w') ftrain = open(txtsavepath + '/train.txt', 'w') fval = open(txtsavepath + '/val.txt', 'w') for i in list: name = total_xml[i][:-4] + '\n' if i in trainval: ftrainval.write(name) if i in train: ftrain.write(name) else: fval.write(name) else: ftest.write(name) ftrainval.close() ftrain.close() fval.close() ftest.close() print('Well finshed')
然后,就是一个标准的VOC格式的dbb训练数据啦,简单不简单牙。
数据检测
注意,这里一定不要省,不然你训练的时候很容易出问题。比如dbb数据里面有些特征框没标注好,标注成了一条直线,导致训练的loss值会变成inf,你需要找出那些没标注好的图片然后把它删了。
我写的检查程序如下。注意,检查出来,删掉之后,要重新生成ImageSet/Main下的train.txt文件。
import json with open('processed_data\TRAIN_objects.json','r') as obj: a=json.load(obj) with open('processed_data\TRAIN_images.json','r') as obj: b=json.load(obj) for i in range(0,len(a),1): boxes=a[i]['boxes'] for boxe in boxes: if boxe[0]==boxe[2]: print(b[i]) if boxe[1]==boxe[3]: print(b[i])
编写训练程序
import time import torch.backends.cudnn as cudnn import torch.optim import torch.utils.data from model import SSD300, MultiBoxLoss from datasets import PascalVOCDataset from utils import * from torch.optim.lr_scheduler import ReduceLROnPlateau # Data parameters data_folder = 'processed_data' #训练数据路径文件所在的文件夹 keep_difficult = True #在voc数据标注里面,有difficult这一项,这里就是决定要不要用这个。 # Model parameters # Not too many here since the SSD300 has a very specific structure n_classes = len(label_map) # 分类的类别数,这个label_map是从utils里面导入进来的。 device = torch.device("cuda" if torch.cuda.is_available() else "cpu") # Learning parameters #checkpoint=None checkpoint = 'weights/MobilenetV3_Large-ssd300.pth.tar' #这个是导入预训练权值。 batch_size = 16 # batch size # iterations = 120000 # number of iterations to train 120000 workers = 8 #导入数据的进程数。进程数越多,导入得更快。 print_freq = 10 #决定每过多少个batchsize输出一次训练信息。 lr =1e-3 # learning rate #decay_lr_to = 0.1 # decay learning rate to this fraction of the existing learning rate momentum = 0.9 # momentum weight_decay = 5e-4 # weight decay:加入权重衰减,收敛得会更快。 grad_clip = None #这是决定是否采用clip gradients方法,clip gradients方法是一种解决梯度爆炸的方法。 cudnn.benchmark = True #这是一种提高训练效率的方法,一般都会加 def main(): """ Training. """ global start_epoch, label_map, epoch, checkpoint, decay_lr_at #初始化模型,或者加载预训练权重 if checkpoint is None: #如果没有预训练权重,则初始化模型 print("checkpoint none") start_epoch = 0 model = SSD300(n_classes=n_classes) #在这个地方导入模型 # Initialize the optimizer, with twice the default learning rate for biases, as in the original Caffe repo biases = list() not_biases = list() for param_name, param in model.named_parameters(): #model.named_parameters()给出网络的名字和参数迭代器 if param.requires_grad: #判断是否是需要求导的参数 if param_name.endswith('.bias'): #如果是以bias结尾的参数名,则需要加偏置。 biases.append(param) else: #否则不需要加偏置。 not_biases.append(param) # differnet optimizer # optimizer = torch.optim.SGD(params=[{'params': biases, 'lr': 2 * lr}, {'params': not_biases}], # lr=lr, momentum=momentum, weight_decay=weight_decay) optimizer = torch.optim.SGD(params=[{'params': biases, 'lr': lr}, {'params': not_biases}], lr=lr, momentum=momentum, weight_decay=weight_decay) #optimizer = torch.optim.SGD(params=[{'params':model.parameters(), 'lr': 2 * lr}, {'params': model.parameters}], lr=lr, momentum=momentum, weight_decay=weight_decay) else: print("checkpoint load") checkpoint = torch.load(checkpoint,map_location='cuda:0') start_epoch = checkpoint['epoch'] + 1 #这个是告诉你,这个预训练权值之前已经训练了多少次迭代 print('\nLoaded checkpoint from epoch %d.\n' % start_epoch) model = checkpoint['model'] optimizer = checkpoint['optimizer'] # Move to default device model = model.to(device) criterion = MultiBoxLoss(priors_cxcy=model.priors_cxcy).to(device) #初始化损失函与先验框,这个model.priors_cxcy返回的是一组初始化产生的先验框 # Custom dataloaders train_dataset = PascalVOCDataset(data_folder,split='train',keep_difficult=keep_difficult) #返回image, boxes, labels, difficulties train_loader = torch.utils.data.DataLoader(train_dataset, batch_size=batch_size, shuffle=True, collate_fn=train_dataset.collate_fn, num_workers=workers, pin_memory=True) #将数据按照batchsize封装成tensor。 # Calculate total number of epochs to train and the epochs to decay learning rate at (i.e. convert iterations to epochs) # To convert iterations to epochs, divide iterations by the number of iterations per epoch # now it is mobilenet v3,VGG paper trains for 120,000 iterations with a batch size of 32, decays after 80,000 and 100,000 iterations, epochs = 800 # decay_lr_at =[154, 193] # print("decay_lr_at:",decay_lr_at) print("epochs:",epochs) for param_group in optimizer.param_groups: #动态调节优化器学习率 optimizer.param_groups[1]['lr']=lr print("learning rate. The new LR is %f\n" % (optimizer.param_groups[1]['lr'],)) # Epochs,I try to use different learning rate shcheduler #different scheduler six way you could try #scheduler = torch.optim.lr_scheduler.CosineAnnealingLR(optimizer,T_max = (epochs // 7) + 1) # 下面这句话是根据epoch动态调整学习率的方法 scheduler = ReduceLROnPlateau(optimizer,mode="min",factor=0.1,patience=15,verbose=True, threshold=0.00001, threshold_mode='rel', cooldown=0, min_lr=0, eps=1e-08) for epoch in range(start_epoch, epochs): #在这里面训练 # Decay learning rate at particular epochs # if epoch in decay_lr_at: # adjust_learning_rate_epoch(optimizer,epoch) # One epoch's training train(train_loader=train_loader, model=model, criterion=criterion, optimizer=optimizer, epoch=epoch) print("epoch loss:",train_loss) scheduler.step(train_loss) #这一步是对学习率进行调整 # Save checkpoint save_checkpoint(epoch, model, optimizer) def train(train_loader, model, criterion, optimizer, epoch): model.train() #启用BatchNormalization与Dropout batch_time = AverageMeter() #AverageMeter()这个类是用来记录数据的最新,平均,总和,计数的值的,里面就两个函数(reset和update)看源码就懂了 data_time = AverageMeter() losses = AverageMeter() start = time.time() global train_loss # Batches for i, (images, boxes, labels, _) in enumerate(train_loader): data_time.update(time.time() - start) # if(i%200==0): # adjust_learning_rate_iter(optimizer,epoch) # print("batch id:",i)#([8, 3, 300, 300]) #N=8 # Move to default device images = images.to(device) # (batch_size (N), 3, 300, 300) boxes = [b.to(device) for b in boxes] labels = [l.to(device) for l in labels] # Forward prop. predicted_locs, predicted_scores = model(images) # (N, anchor_boxes_size, 4), (N, anchor_boxes_size, n_classes) # Loss loss = criterion(predicted_locs, predicted_scores, boxes, labels) # scalar train_loss=loss #print("training",train_loss) # Backward prop. optimizer.zero_grad()#初始化梯度 loss.backward()# 根据loss的值求相应weight的梯度 # Clip gradients, if necessary if grad_clip is not None: #防止梯度爆炸用的 clip_gradient(optimizer, grad_clip) # Update model optimizer.step() #这一步是更新权值 losses.update(loss.item(), images.size(0)) batch_time.update(time.time() - start) start = time.time() # Print status if i % print_freq == 0: print('Epoch: [{0}][{1}/{2}][{3}]\t' 'Batch Time {batch_time.val:.3f} ({batch_time.avg:.3f})\t' 'Data Time {data_time.val:.3f} ({data_time.avg:.3f})\t' 'Loss {loss.val:.4f} ({loss.avg:.4f})\t'.format(epoch, i, len(train_loader),optimizer.param_groups[1]['lr'], batch_time=batch_time, data_time=data_time, loss=losses)) #break #test del predicted_locs, predicted_scores, images, boxes, labels # free some memory since their histories may be stored def adjust_learning_rate_epoch(optimizer,cur_epoch): """ Scale learning rate by a specified factor. :param optimizer: optimizer whose learning rate must be shrunk. :param scale: factor to multiply learning rate with. """ for param_group in optimizer.param_groups: param_group['lr'] = param_group['lr'] * 0.1 print("DECAYING learning rate. The new LR is %f\n" % (optimizer.param_groups[1]['lr'],)) #warmup ,how much learning rate. def adjust_learning_rate_iter(optimizer,cur_epoch): if(cur_epoch==0 or cur_epoch==1 ): for param_group in optimizer.param_groups: param_group['lr'] =param_group['lr'] + 0.0001 print("DECAYING learning rate iter. The new LR is %f\n" % (optimizer.param_groups[1]['lr'],)) if __name__ == '__main__': main()
这个程序是以调用json格式的数据进行读取训练数据和训练标签的,所以,训练之前还需要转一下数据格式,代码如下。
#使用注意事项,使用试记得修改voc_labels为你自己训练数据的标签 #from utils import create_data_lists import os import xml.etree.ElementTree as ET import json # Label map #voc_labels = ('aeroplane', 'bicycle', 'bird', 'boat', 'bottle', 'bus', 'car', 'cat', 'chair', 'cow', 'diningtable', #'dog', 'horse', 'motorbike', 'person', 'pottedplant', 'sheep', 'sofa', 'train', 'tvmonitor') #voc_labels=('bus','car') voc_labels=('bus', 'traffic light', 'traffic sign', 'person', 'bike', 'truck', 'motor', 'car', 'train','rider') label_map = {k: v + 1 for v, k in enumerate(voc_labels)} label_map['background'] = 0 rev_label_map = {v: k for k, v in label_map.items()} # Inverse mapping def parse_annotation(annotation_path): tree = ET.parse(annotation_path) root = tree.getroot() boxes = list() labels = list() difficulties = list() for category in root.iter('category'): difficult=int(0.) label=category.text.lower().strip() if label not in label_map: continue labels.append(label_map[label]) difficulties.append(difficult) for box2d in root.iter('box2d'): x1=int(float(box2d.find('x1').text)) y1=int(float(box2d.find('y1').text)) x2=int(float(box2d.find('x2').text)) y2=int(float(box2d.find('y2').text)) boxes.append([x1,y1,x2,y2]) return {'boxes': boxes, 'labels': labels,'difficulties':difficulties} def create_data_lists(voc07_path,output_folder): """ Create lists of images, the bounding boxes and labels of the objects in these images, and save these to file. :param voc07_path: path to the 'VOC2007' folder :param voc12_path: path to the 'VOC2012' folder :param output_folder: folder where the JSONs must be saved """ voc07_path = os.path.abspath(voc07_path) train_images = list() train_objects = list() n_objects = 0 # Training data path=voc07_path # Find IDs of images in training data print(path) with open(os.path.join(path, 'ImageSets/Main/trainval.txt')) as f: ids = f.read().splitlines() for id in ids: # Parse annotation's XML file objects = parse_annotation(os.path.join(path, 'Annotations', id + '.xml')) if len(objects) == 0: continue n_objects += len(objects) train_objects.append(objects) train_images.append(os.path.join(path, 'JPEGImages', id + '.jpg')) assert len(train_objects) == len(train_images) # Save to file with open(os.path.join(output_folder, 'TRAIN_images.json'), 'w') as j: #写入训练图片路径 json.dump(train_images, j) with open(os.path.join(output_folder, 'TRAIN_objects.json'), 'w') as j: #写入训练标签信息 json.dump(train_objects, j) with open(os.path.join(output_folder, 'label_map.json'), 'w') as j: #写入训练标签类别 json.dump(label_map, j) # save label map too print('\nThere are %d training images containing a total of %d objects. Files have been saved to %s.' % ( len(train_images), n_objects, os.path.abspath(output_folder))) # Test data test_images = list() test_objects = list() n_objects = 0 # Find IDs of images in the test data with open(os.path.join(voc07_path, 'ImageSets/Main/trainval.txt')) as f: ids = f.read().splitlines() for id in ids: # Parse annotation's XML file objects = parse_annotation(os.path.join(voc07_path, 'Annotations', id + '.xml')) if len(objects) == 0: continue test_objects.append(objects) n_objects += len(objects) test_images.append(os.path.join(voc07_path, 'JPEGImages', id + '.jpg')) assert len(test_objects) == len(test_images) # Save to file with open(os.path.join(output_folder, 'TEST_images.json'), 'w') as j: json.dump(test_images, j) with open(os.path.join(output_folder, 'TEST_objects.json'), 'w') as j: json.dump(test_objects, j) print('\nThere are %d test images containing a total of %d objects. Files have been saved to %s.' % ( len(test_images), n_objects, os.path.abspath(output_folder))) if __name__ == '__main__': create_data_lists(voc07_path='D:/study/internship/work_file/Dataset/bdd100k/bdd1k',output_folder='processed_data')
训练过程如下图所示。
step3:预测
终于到预测啦,享受革命成果的时候到了。
代码如下。注意,虽然在程序中没有引入神经网络模型文件,但是这个模型文件是必须在相对路径下才能运行的,因为这个模型文件的名字保存在权重文件里面,会要调用的。
from torchvision import transforms from utils import * from PIL import Image, ImageDraw, ImageFont import time device = torch.device("cuda" if torch.cuda.is_available() else "cpu") # Load model checkpoint checkpoint = 'checkpoint_ssd300.pth.tar' checkpoint = torch.load(checkpoint,map_location='cuda:0') print(checkpoint) start_epoch = checkpoint['epoch'] + 1 print('\nLoaded checkpoint from epoch %d.\n' % start_epoch) model = checkpoint['model'] model = model.to(device) model.eval() #如果是预测,使用这个;如果是训练,使用model.train() def detect(original_image, min_score, max_overlap, top_k, suppress=None): """ Detect objects in an image with a trained SSD300, and visualize the results. :param original_image: image, a PIL Image :param min_score: minimum threshold for a detected box to be considered a match for a certain class :param max_overlap: maximum overlap two boxes can have so that the one with the lower score is not suppressed via Non-Maximum Suppression (NMS) :param top_k: if there are a lot of resulting detection across all classes, keep only the top 'k' :param suppress: classes that you know for sure cannot be in the image or you do not want in the image, a list :return: annotated image, a PIL Image """ # Transform resize = transforms.Resize((300, 300)) to_tensor = transforms.ToTensor() #这句话 normalize = transforms.Normalize(mean=[0.485, 0.456, 0.406],std=[0.229, 0.224, 0.225]) image = normalize(to_tensor(resize(original_image))) # Move to default device image = image.to(device) #这句话是将图片的张量读取到GPU上。 # Forward prop. predicted_locs, predicted_scores = model(image.unsqueeze(0)) #unsqueeze用于添加维度。 ###############################################后面都是解码与画图了 # Detect objects in SSD output det_boxes, det_labels, det_scores = model.detect_objects(predicted_locs, predicted_scores, min_score=min_score, max_overlap=max_overlap, top_k=top_k) #将预测结果进行解码 # Move detections to the CPU det_boxes = det_boxes[0].to('cpu') # Transform to original image dimensions original_dims = torch.FloatTensor( [original_image.width, original_image.height, original_image.width, original_image.height]).unsqueeze(0) det_boxes = det_boxes * original_dims # Decode class integer labels det_labels = [rev_label_map[l] for l in det_labels[0].to('cpu').tolist()] print(det_labels) # If no objects found, the detected labels will be set to ['0.'], i.e. ['background'] in SSD300.detect_objects() in model.py if det_labels == ['background']: # Just return original image return original_image # Annotate annotated_image = original_image draw = ImageDraw.Draw(annotated_image) font = ImageFont.truetype("simhei.ttf", 15) # Suppress specific classes, if needed for i in range(det_boxes.size(0)): if suppress is not None: if det_labels[i] in suppress: continue # Boxes box_location = det_boxes[i].tolist() draw.rectangle(xy=box_location, outline=label_color_map[det_labels[i]]) draw.rectangle(xy=[l + 1. for l in box_location], outline=label_color_map[ det_labels[i]]) # a second rectangle at an offset of 1 pixel to increase line thickness # draw.rectangle(xy=[l + 2. for l in box_location], outline=label_color_map[ # det_labels[i]]) # a third rectangle at an offset of 1 pixel to increase line thickness # draw.rectangle(xy=[l + 3. for l in box_location], outline=label_color_map[ # det_labels[i]]) # a fourth rectangle at an offset of 1 pixel to increase line thickness # Text text_size = font.getsize(det_labels[i].upper()) text_location = [box_location[0] + 2., box_location[1] - text_size[1]] textbox_location = [box_location[0], box_location[1] - text_size[1], box_location[0] + text_size[0] + 4., box_location[1]] draw.rectangle(xy=textbox_location, fill=label_color_map[det_labels[i]]) draw.text(xy=text_location, text=det_labels[i].upper(), fill='white', font=font) del draw return annotated_image if __name__ == '__main__': img_path = 'feiji1.jpg' original_image = Image.open(img_path, mode='r') original_image = original_image.convert('RGB') detect(original_image, min_score=0.2, max_overlap=0.5, top_k=200).show()
总结
以上为个人经验,希望能给大家一个参考,也希望大家多多支持码农之家。