杭州知名建设网站设计,设计网站 问题,wordpress 添加缩略图,手机创建网站免费【猫狗脸部定位与识别】 1 引言2 损失函数3 The Oxford-IIIT Pet Dataset数据集4 数据预处理4 创建模型输入5 自定义数据集加载方式6 显示一批次数据7 创建定位模型8 模型训练9 绘制损失曲线10 模型保存与预测 1 引言
猫狗脸部定位与识别分为定位和识别#xff0c;即定位猫狗… 【猫狗脸部定位与识别】 1 引言2 损失函数3 The Oxford-IIIT Pet Dataset数据集4 数据预处理4 创建模型输入5 自定义数据集加载方式6 显示一批次数据7 创建定位模型8 模型训练9 绘制损失曲线10 模型保存与预测 1 引言
猫狗脸部定位与识别分为定位和识别即定位猫狗脸部位置识别脸部是狗还是猫。 针对既要预测类别还要定位目标位置的问题首先使用卷积模型提取图片特征然后分别连接2个输出一个做回归输出位置ximyminxmaxymax另一个做分类输出两个类别概率01。
2 损失函数
回归问题使用L2损失–均方误差MSE_loss)分类问题使用交叉熵损失CrossEntropyLoss)将两者相加即为总损失。
3 The Oxford-IIIT Pet Dataset数据集
数据来源https://www.robots.ox.ac.uk/~vgg/data/pets/ 包含两类猫和狗共37种宠物每种宠物约有200张图。 dataset文件结构如下 ±–dataset | ±–annotations | | ±–trimaps | | —xmls | —images
images包含所有猫狗图片annotation包含标签数据和trimaps三元图[012]标签图,xmls包含脸部坐标位置和种类。
4 数据预处理
1导入基本库
import torch
import torch.nn as nn
import torch.nn.functional as F
from torch.utils import dataimport numpy as np
import matplotlib.pyplot as plt
%matplotlib inlineimport torchvision
from torchvision import transforms
import osfrom lxml import etree # etree网页解析模块 # 安装 lxml conda install lxml
from matplotlib.patches import Rectangle # Rectangle画矩形
import globfrom PIL import Image2读取一张图片
BATCH_SIZE 4
pil_img Image.open(rdataset/images/Abyssinian_1.jpg)
np_img np.array(pil_img)
print(np_img.shape)
plt.imshow(np_img)
plt.show()(3) 打开一个xml文件
xml open(rdataset/annotations/xmls/Abyssinian_1.xml).read()
sel etree.HTML(xml)
width sel.xpath(//size/width/text())[0]height sel.xpath(//size/height/text())[0]
xmin sel.xpath(//bndbox/xmin/text())[0]
ymin sel.xpath(//bndbox/ymin/text())[0]
xmax sel.xpath(//bndbox/xmax/text())[0]
ymax sel.xpath(//bndbox/ymax/text())[0]width int(width)
height int(height)
xmin int(xmin)
ymin int(ymin)
xmax int(xmax)
ymax int(ymax)plt.imshow(np_img)
rect Rectangle((xmin, ymin), (xmax-xmin), (ymax-ymin), fillFalse, colorred)
ax plt.gca()
ax.axes.add_patch(rect)
plt.show()4当图片的尺寸发生变化时脸部的定位坐标要相对原来的宽高按比例缩放xminxmin* new_ width/old_width)
img pil_img.resize((224, 224))xmin xmin*224/width
ymin ymin*224/height
xmax xmax*224/width
ymax ymax*224/heightplt.imshow(img)
rect Rectangle((xmin, ymin), (xmax-xmin), (ymax-ymin), fillFalse, colorred)
ax plt.gca()
ax.axes.add_patch(rect)
plt.show()4 创建模型输入
xml和images数量不一致并不是所有图片都具有标签所以需要逐一找出具有位置信息的图片并保存地址
images glob.glob(dataset/images/*.jpg)
print(images[:5])
print(len(images)) xmls glob.glob(dataset/annotations/xmls/*.xml)
print(len(xmls)) # xml和images数量不一致并不是所有图片都具有标签所以需要逐一找出具有位置信息的图片并保存地址
print(xmls[:5]) xmls_names [x.split(/)[-1].split(.xml)[0] for x in xmls]
print(xmls_names[:3])
print(len(xmls_names))# 遍历所有具有定位坐标的图片并保存图片路径
imgs [img for img in images if img.split(/)[-1].split(.jpg)[0] in xmls_names]print(len(imgs))
print(imgs[:5])# 重新定义尺寸为224并将定位和类别保存到labels中
scal 224
name_to_id {cat:0, dog:1}
id_to_name {0:cat, 1:dog}
def to_labels(path):xml open(r{}.format(path)).read()sel etree.HTML(xml)name sel.xpath(//object/name/text())[0]width int(sel.xpath(//size/width/text())[0])height int(sel.xpath(//size/height/text())[0])xmin int(sel.xpath(//bndbox/xmin/text())[0])ymin int(sel.xpath(//bndbox/ymin/text())[0])xmax int(sel.xpath(//bndbox/xmax/text())[0])ymax int(sel.xpath(//bndbox/ymax/text())[0])return (xmin/width, ymin/height, xmax/width, ymax/height, name_to_id.get(name))
labels [to_labels(path) for path in xmls]np.random.seed(2022)
index np.random.permutation(len(imgs))# 划分训练集和测试集
images np.array(imgs)[index]
print(images[0])
labels np.array(labels, np.float32)[index]
print(labels[0])sep int(len(imgs)*0.8)
train_images images[ :sep]
train_labels labels[ :sep]
test_images images[sep: ]
test_labels labels[sep: ]输出如下
[dataset/images/german_shorthaired_102.jpg,dataset/images/havanese_150.jpg,dataset/images/great_pyrenees_143.jpg,dataset/images/Bombay_41.jpg,dataset/images/newfoundland_2.jpg]
7390
3686[dataset/annotations/xmls/american_bulldog_178.xml,dataset/annotations/xmls/scottish_terrier_114.xml,dataset/annotations/xmls/american_pit_bull_terrier_179.xml,dataset/annotations/xmls/Birman_171.xml,dataset/annotations/xmls/staffordshire_bull_terrier_107.xml][american_bulldog_178,scottish_terrier_114,american_pit_bull_terrier_179]36863686[dataset/images/german_shorthaired_102.jpg,dataset/images/havanese_150.jpg,dataset/images/great_pyrenees_143.jpg,dataset/images/samoyed_137.jpg,dataset/images/newfoundland_189.jpg][dataset/annotations/xmls/american_bulldog_178.xml,dataset/annotations/xmls/scottish_terrier_114.xml,dataset/annotations/xmls/american_pit_bull_terrier_179.xml,dataset/annotations/xmls/Birman_171.xml,dataset/annotations/xmls/staffordshire_bull_terrier_107.xml]dataset/images/pug_184.jpg
[0.19117647 0.21 0.8 0.624 1. ]5 自定义数据集加载方式
transform transforms.Compose([transforms.Resize((224, 224)),transforms.ToTensor(),
])class Oxford_dataset(data.Dataset):def __init__(self, img_paths, labels, transform):self.imgs img_pathsself.labels labelsself.transforms transformdef __getitem__(self, index):img self.imgs[index]label self.labels[index]pil_img Image.open(img) pil_img pil_img.convert(RGB)pil_img transform(pil_img)return pil_img, label[:4],label[4] # 图片像素(3, 224, 224)定位4个值分类1个值def __len__(self):return len(self.imgs)train_dataset Oxford_dataset(train_images, train_labels, transform)
test_dataset Oxford_dataset(test_images, test_labels, transform)
train_dl data.DataLoader(train_dataset,batch_sizeBATCH_SIZE,shuffleTrue)
test_dl data.DataLoader(test_dataset,batch_sizeBATCH_SIZE)6 显示一批次数据
(imgs_batch, labels1_batch,labels2_batch) next(iter(train_dl))
print(imgs_batch.shape, labels1_batch.shape,labels2_batch.shape)plt.figure(figsize(12, 8))
for i, (img, label_1,label_2) in enumerate(zip(imgs_batch[:6], labels1_batch[:6],labels2_batch[:6])):img img.permute(1,2,0).numpy() # 1)/2plt.subplot(2, 3, i1)plt.imshow(img)plt.title(id_to_name.get(label_2.item()))xmin, ymin, xmax, ymax tuple(label_1.numpy()*224)rect Rectangle((xmin, ymin), (xmax-xmin), (ymax-ymin), fillFalse, colorred)ax plt.gca()ax.axes.add_patch(rect)
plt.savefig(pics/example.jpg, dpi400)输出如下
(torch.Size([4, 3, 224, 224]), torch.Size([4, 4]), torch.Size([4]))在这里插入代码片7 创建定位模型
借用renet50网络模型的卷积部分而分类部分自定义如下
resnet torchvision.models.resnet50(pretrainedTrue)
#print(resnet)
in_f resnet.fc.in_features
print(in_f)
print(list(resnet.children())) # 以生成器形式返回模型所包含的所有层输出如下
2048
[Conv2d(3, 64, kernel_size(7, 7), stride(2, 2), padding(3, 3), biasFalse), BatchNorm2d(64, eps1e-05, momentum0.1, affineTrue, track_running_statsTrue), ReLU(inplaceTrue), MaxPool2d(kernel_size3, stride2, padding1, dilation1, ceil_modeFalse), Sequential((0): Bottleneck((conv1): Conv2d(64, 64, kernel_size(1, 1), stride(1, 1), biasFalse)(bn1): BatchNorm2d(64, eps1e-05, momentum0.1, affineTrue, track_running_statsTrue)(conv2): Conv2d(64, 64, kernel_size(3, 3), stride(1, 1), padding(1, 1), biasFalse)(bn2): BatchNorm2d(64, eps1e-05, momentum0.1, affineTrue, track_running_statsTrue)(conv3): Conv2d(64, 256, kernel_size(1, 1), stride(1, 1), biasFalse)(bn3): BatchNorm2d(256, eps1e-05, momentum0.1, affineTrue, track_running_statsTrue)(relu): ReLU(inplaceTrue)(downsample): Sequential((0): Conv2d(64, 256, kernel_size(1, 1), stride(1, 1), biasFalse)(1): BatchNorm2d(256, eps1e-05, momentum0.1, affineTrue, track_running_statsTrue)))(1): Bottleneck((conv1): Conv2d(256, 64, kernel_size(1, 1), stride(1, 1), biasFalse)(bn1): BatchNorm2d(64, eps1e-05, momentum0.1, affineTrue, track_running_statsTrue)(conv2): Conv2d(64, 64, kernel_size(3, 3), stride(1, 1), padding(1, 1), biasFalse)(bn2): BatchNorm2d(64, eps1e-05, momentum0.1, affineTrue, track_running_statsTrue)(conv3): Conv2d(64, 256, kernel_size(1, 1), stride(1, 1), biasFalse)(bn3): BatchNorm2d(256, eps1e-05, momentum0.1, affineTrue, track_running_statsTrue)(relu): ReLU(inplaceTrue))(2): Bottleneck(
...(bn3): BatchNorm2d(2048, eps1e-05, momentum0.1, affineTrue, track_running_statsTrue)(relu): ReLU(inplaceTrue))
), AdaptiveAvgPool2d(output_size(1, 1)), Linear(in_features2048, out_features1000, biasTrue)]自定义分类和定位模型如下
class Net(nn.Module):def __init__(self):super(Net, self).__init__()self.conv_base nn.Sequential(*list(resnet.children())[:-1]) # 以生成器方式返回模型所包含的所有层self.fc1 nn.Linear(in_f, 4) # 位置坐标self.fc2 nn.Linear(in_f, 2) # 两分类概率def forward(self, x):x self.conv_base(x)x x.view(x.size(0), -1)x1 self.fc1(x)x2 self.fc2(x)return x1,x28 模型训练
model Net()device cuda if torch.cuda.is_available() else cpu
print(Using {} device.format(device))model model.to(device)
loss_mse nn.MSELoss()
loss_crossentropy nn.CrossEntropyLoss()from torch.optim import lr_scheduler
optimizer torch.optim.Adam(model.parameters(), lr1e-4)
exp_lr_scheduler lr_scheduler.StepLR(optimizer, step_size7, gamma0.5, verbose True)def train(dataloader, model, loss_mse,loss_crossentropy, optimizer): num_batches len(dataloader)train_loss 0model.train()for X, y1,y2 in dataloader:X, y1, y2 X.to(device), y1.to(device), y2.to(device)# Compute prediction errory1_pred, y2_pred model(X)loss loss_mse(y1_pred, y1) loss_crossentropy(y2_pred,y2.long())# Backpropagationoptimizer.zero_grad()loss.backward()optimizer.step()with torch.no_grad():train_loss loss.item()train_loss / num_batchesreturn train_lossdef test(dataloader, model,loss_mse,loss_crossentropy): num_batches len(dataloader)model.eval()test_loss 0with torch.no_grad():for X, y1, y2 in dataloader:X, y1, y2 X.to(device), y1.to(device), y2.to(device)# Compute prediction errory1_pred, y2_pred model(X)loss loss_mse(y1_pred, y1) loss_crossentropy(y2_pred,y2.long())test_loss loss.item()test_loss / num_batchesreturn test_lossdef fit(epochs, train_dl, test_dl, model, loss_mse,loss_crossentropy, optimizer): train_loss []test_loss []for epoch in range(epochs):epoch_loss train(train_dl, model, loss_mse,loss_crossentropy, optimizer) #epoch_test_loss test(test_dl, model, loss_mse,loss_crossentropy) #train_loss.append(epoch_loss)test_loss.append(epoch_test_loss)exp_lr_scheduler.step()template (epoch:{:2d}/{:2d}, train_loss: {:.5f}, test_loss: {:.5f})print(template.format(epoch1,epochs, epoch_loss, epoch_test_loss))print(Done!)return train_loss, test_lossepochs 50train_loss, test_loss fit(epochs, train_dl, test_dl, model, loss_mse,loss_crossentropy, optimizer) #
输出如下
Using cuda deviceAdjusting learning rate of group 0 to 1.0000e-04.
epoch: 1/50, train_loss: 0.68770, test_loss: 0.69263
Adjusting learning rate of group 0 to 1.0000e-04.
epoch: 2/50, train_loss: 0.64950, test_loss: 0.69668
Adjusting learning rate of group 0 to 1.0000e-04.
epoch: 3/50, train_loss: 0.63532, test_loss: 0.71381
Adjusting learning rate of group 0 to 1.0000e-04.
epoch: 4/50, train_loss: 0.61014, test_loss: 0.74332
Adjusting learning rate of group 0 to 1.0000e-04.
epoch: 5/50, train_loss: 0.57072, test_loss: 0.76198
Adjusting learning rate of group 0 to 1.0000e-04.
epoch: 6/50, train_loss: 0.45499, test_loss: 0.93127
Adjusting learning rate of group 0 to 5.0000e-05.
epoch: 7/50, train_loss: 0.31113, test_loss: 0.96860
Adjusting learning rate of group 0 to 5.0000e-05.
epoch: 8/50, train_loss: 0.14169, test_loss: 1.35223
Adjusting learning rate of group 0 to 5.0000e-05.
epoch: 9/50, train_loss: 0.08092, test_loss: 1.50338
Adjusting learning rate of group 0 to 5.0000e-05.
epoch:10/50, train_loss: 0.06381, test_loss: 1.49817
Adjusting learning rate of group 0 to 5.0000e-05.
epoch:11/50, train_loss: 0.05252, test_loss: 1.49126
Adjusting learning rate of group 0 to 5.0000e-05.
epoch:12/50, train_loss: 0.04227, test_loss: 1.45301
Adjusting learning rate of group 0 to 5.0000e-05.
...
epoch:49/50, train_loss: 0.00632, test_loss: 2.19361
Adjusting learning rate of group 0 to 7.8125e-07.
epoch:50/50, train_loss: 0.00594, test_loss: 2.16411
Done!9 绘制损失曲线
结果较差需要优化网络模型但思路不变。
plt.figure()
plt.plot(range(1, len(train_loss)1), train_loss, r, labelTraining loss)
plt.plot(range(1, len(train_loss)1), test_loss, b, labelValidation loss)
plt.title(Training and Validation Loss)
plt.xlabel(Epoch)
plt.ylabel(Loss Value)
plt.legend()
plt.show()10 模型保存与预测
PATH model_path/location_model.pth
torch.save(model.state_dict(), PATH)
model Net()
model.load_state_dict(torch.load(PATH))
model model.cuda() #.cpu() 模型使用GPU或CPU加载plt.figure(figsize(8, 8))
imgs, _,_ next(iter(test_dl))
imgs imgs.to(device)
out1,out2 model(imgs)
for i in range(4):plt.subplot(2, 2, i1)plt.imshow(imgs[i].permute(1,2,0).detach().cpu())plt.title(id_to_name.get(torch.argmax(out2[i],0).item()))xmin, ymin, xmax, ymax tuple(out1[i].detach().cpu().numpy()*224)rect Rectangle((xmin, ymin), (xmax-xmin), (ymax-ymin), fillFalse, colorred)ax plt.gca()ax.axes.add_patch(rect)
plt.savefig(pics/predict.jpg,dpi 400)
