【猫狗数据集】可视化resnet18的输出

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最后读取训练好的模型，可视化特征图，至此猫狗数据集系列就完结了，后面准备着手pyorch-ssd训练自己的数据集（比如是否口罩检测）。

直接看代码吧：visual.py

import cv2
import time
import os
import matplotlib.pyplot as plt
import torch
from torch import nn
import torchvision.models as models
import torchvision.transforms as transforms
import numpy as np
import torchvision
import torch.nn as nn

savepath=r'results'
if not os.path.exists(savepath):
    os.mkdir(savepath)

def load_model():
  model=torchvision.models.resnet18(pretrained=False)
  model.fc = nn.Linear(model.fc.in_features,2,bias=False)
  save_path="/content/drive/My Drive/colab notebooks/output/resnet18_best.t7" 
  checkpoint = torch.load(save_path,map_location=lambda storage, loc: storage)
  model.load_state_dict(checkpoint['model'])
  return model 

def draw_features(width,height,x,savename):
    tic=time.time()
    fig = plt.figure(figsize=(16, 16))
    fig.subplots_adjust(left=0.05, right=0.95, bottom=0.05, top=0.95, wspace=0.05, hspace=0.05)
    for i in range(width*height):
        plt.subplot(height,width, i + 1)
        plt.axis('off')
        img = x[0, i, :, :]
        pmin = np.min(img)
        pmax = np.max(img)
        img = ((img - pmin) / (pmax - pmin + 0.000001))*255  #float在[0，1]之间，转换成0-255
        img=img.astype(np.uint8)  #转成unit8
        img=cv2.applyColorMap(img, cv2.COLORMAP_JET) #生成heat map
        img = img[:, :, ::-1]#注意cv2（BGR）和matplotlib(RGB)通道是相反的
        plt.imshow(img)
        #print("{}/{}".format(i+1,width*height))
    fig.savefig(savename, dpi=100)
    fig.clf()
    plt.close()
    print("time:{}".format(time.time()-tic))


class ft_net(nn.Module):

    def __init__(self):
        super(ft_net, self).__init__()
        model=load_model()
        self.model = model

    def forward(self, x):
        if True: # draw features or not
            x = self.model.conv1(x)
            draw_features(8,8,x.cpu().numpy(),"{}/f1_conv1.png".format(savepath))

            x = self.model.bn1(x)
            draw_features(8, 8, x.cpu().numpy(),"{}/f2_bn1.png".format(savepath))

            x = self.model.relu(x)
            draw_features(8, 8, x.cpu().numpy(), "{}/f3_relu.png".format(savepath))

            x = self.model.maxpool(x)
            draw_features(8, 8, x.cpu().numpy(), "{}/f4_maxpool.png".format(savepath))

            x = self.model.layer1(x)
            draw_features(8, 8, x.cpu().numpy(), "{}/f5_layer1.png".format(savepath))

            x = self.model.layer2(x)
            draw_features(8, 16, x.cpu().numpy(), "{}/f6_layer2.png".format(savepath))

            x = self.model.layer3(x)
            draw_features(16, 16, x.cpu().numpy(), "{}/f7_layer3.png".format(savepath))

            x = self.model.layer4(x)
            draw_features(16, 32, x.cpu().numpy(), "{}/f8_layer4.png".format(savepath))
            #draw_features(16, 32, x.cpu().numpy()[:, 0:1024, :, :], "{}/f8_layer4_1.png".format(savepath))
            #draw_features(16, 32, x.cpu().numpy()[:, 1024:2048, :, :], "{}/f8_layer4_2.png".format(savepath))

            x = self.model.avgpool(x)
            #plt.plot(np.linspace(1, 2048, 2048), x.cpu().numpy()[0, :, 0, 0])
            plt.plot(np.linspace(1, 512, 512), x.cpu().numpy()[0, :, 0, 0])
            plt.savefig("{}/f9_avgpool.png".format(savepath))
            plt.clf()
            plt.close()

            x = x.view(x.size(0), -1)
            x = self.model.fc(x)
            #plt.plot(np.linspace(1, 1000, 1000), x.cpu().numpy()[0, :])
            plt.plot(np.linspace(1, 2, 2), x.cpu().numpy()[0, :])
            plt.savefig("{}/f10_fc.png".format(savepath))
            plt.clf()
            plt.close()
        else :
            x = self.model.conv1(x)
            x = self.model.bn1(x)
            x = self.model.relu(x)
            x = self.model.maxpool(x)
            x = self.model.layer1(x)
            x = self.model.layer2(x)
            x = self.model.layer3(x)
            x = self.model.layer4(x)
            x = self.model.avgpool(x)
            x = x.view(x.size(0), -1)
            x = self.model.fc(x)

        return x


model=ft_net()

# pretrained_dict = resnet50.state_dict()
# pretrained_dict = {k: v for k, v in pretrained_dict.items() if k in model_dict}
# model_dict.update(pretrained_dict)
# net.load_state_dict(model_dict)
model.eval（)
img=cv2.imread('/content/drive/My Drive/colab notebooks/image/cat7.jpg')
img=cv2.resize(img,(224,224))
img=cv2.cvtColor(img,cv2.COLOR_BGR2RGB)
transform = transforms.Compose(
    [transforms.ToTensor(),
     transforms.Normalize((0.485, 0.456, 0.406), (0.229, 0.224, 0.225))])
img=transform(img)
img=img.unsqueeze(0)

with torch.no_grad():
    start=time.time()
    out=model(img)
    print("total time:{}".format(time.time()-start))
    result=out.cpu().numpy()
    # ind=np.argmax(out.cpu().numpy())
    ind=np.argsort(result,axis=1)
    """
    for i in range(5):
        print("predict:top {} = cls {} : score {}".format(i+1,ind[0,1000-i-1],result[0,1000-i-1]))
    """
    for i in range(2):
        print("predict:top {} = cls {} : score {}".format(i+1,ind[0,2-i-1],result[0,2-i-1]))
    print("done")

说明：需要注意的地方

• 在draw_features()中的前两个参数的乘积必须为该层输出的通道数目的大小。
• 在GPU上训练的模型要转换成CPU模式。
• 输入的图像转换成测试的格式：图像大小、维度[batchsize,C,H,W]
• 要注意我们的类别是两类：猫和狗

运行：

输出文件夹：

原始图片：

查看每一个文件中的图像：只截取部分

f1_conv1.png 

f2_bn1.png

f3_relu.png 

f4_maxpool.png

f5_layer1.png

f6_layer2.png

f7_layer3.png

f8_layer4.png

f9_avgpool.png

f10_fc.png

横轴是类别编号，纵轴是评分。最后一个图咋好像不太对劲。。

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