查看中间层的特征，需要在定义Model时，在forward时，将中间要显示的层输出。
def forward(self, x):outputs = []x = self.conv1(x)outputs.append(x)x = self.bn1(x)x = self.relu(x)x = self.maxpool(x)x = self.layer1(x)outputs.append(x)# x = self.layer2(x)# x = self.layer3(x)# x = self.layer4(x)## if self.include_top:# x = self.avgpool(x)# x = torch.flatten(x, 1)# x = self.fc(x)return outputs这里在convert1后和layer1后添加到一个列表中，然后输出。后面的就不进行卷积操作了。
import torch.nn as nn
import torchclass BasicBlock(nn.Module):expansion = 1def __init__(self, in_channel, out_channel, stride=1, downsample=None):super(BasicBlock, self).__init__()self.conv1 = nn.Conv2d(in_channels=in_channel, out_channels=out_channel,kernel_size=3, stride=stride, padding=1, bias=False)self.bn1 = nn.BatchNorm2d(out_channel)self.relu = nn.ReLU()self.conv2 = nn.Conv2d(in_channels=out_channel, out_channels=out_channel,kernel_size=3, stride=1, padding=1, bias=False)self.bn2 = nn.BatchNorm2d(out_channel)self.downsample = downsampledef forward(self, x):identity = xif self.downsample is not None:identity = self.downsample(x)out = self.conv1(x)out = self.bn1(out)out = self.relu(out)out = self.conv2(out)out = self.bn2(out)out += identityout = self.relu(out)return outclass Bottleneck(nn.Module):expansion = 4def __init__(self, in_channel, out_channel, stride=1, downsample=None):super(Bottleneck, self).__init__()self.conv1 = nn.Conv2d(in_channels=in_channel, out_channels=out_channel,kernel_size=1, stride=1, bias=False) # squeeze channelsself.bn1 = nn.BatchNorm2d(out_channel)# -----------------------------------------self.conv2 = nn.Conv2d(in_channels=out_channel, out_channels=out_channel,kernel_size=3, stride=stride, bias=False, padding=1)self.bn2 = nn.BatchNorm2d(out_channel)# -----------------------------------------self.conv3 = nn.Conv2d(in_channels=out_channel, out_channels=out_channel*self.expansion,kernel_size=1, stride=1, bias=False) # unsqueeze channelsself.bn3 = nn.BatchNorm2d(out_channel*self.expansion)self.relu = nn.ReLU(inplace=True)self.downsample = downsampledef forward(self, x):identity = xif self.downsample is not None:identity = self.downsample(x)out = self.conv1(x)out = self.bn1(out)out = self.relu(out)out = self.conv2(out)out = self.bn2(out)out = self.relu(out)out = self.conv3(out)out = self.bn3(out)out += identityout = self.relu(out)return outclass ResNet(nn.Module):def __init__(self, block, blocks_num, num_classes=1000, include_top=True):super(ResNet, self).__init__()self.include_top = include_topself.in_channel = 64self.conv1 = nn.Conv2d(3, self.in_channel, kernel_size=7, stride=2,padding=3, bias=False)self.bn1 = nn.BatchNorm2d(self.in_channel)self.relu = nn.ReLU(inplace=True)self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)self.layer1 = self._make_layer(block, 64, blocks_num[0])self.layer2 = self._make_layer(block, 128, blocks_num[1], stride=2)self.layer3 = self._make_layer(block, 256, blocks_num[2], stride=2)self.layer4 = self._make_layer(block, 512, blocks_num[3], stride=2)if self.include_top:self.avgpool = nn.AdaptiveAvgPool2d((1, 1)) # output size = (1, 1)self.fc = nn.Linear(512 * block.expansion, num_classes)for m in self.modules():if isinstance(m, nn.Conv2d):nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu')def _make_layer(self, block, channel, block_num, stride=1):downsample = Noneif stride != 1 or self.in_channel != channel * block.expansion:downsample = nn.Sequential(nn.Conv2d(self.in_channel, channel * block.expansion, kernel_size=1, stride=stride, bias=False),nn.BatchNorm2d(channel * block.expansion))layers = []layers.append(block(self.in_channel, channel, downsample=downsample, stride=stride))self.in_channel = channel * block.expansionfor _ in range(1, block_num):layers.append(block(self.in_channel, channel))return nn.Sequential(*layers)def forward(self, x):outputs = []x = self.conv1(x)outputs.append(x)x = self.bn1(x)x = self.relu(x)x = self.maxpool(x)x = self.layer1(x)outputs.append(x)# x = self.layer2(x)# x = self.layer3(x)# x = self.layer4(x)## if self.include_top:# x = self.avgpool(x)# x = torch.flatten(x, 1)# x = self.fc(x)return outputsdef resnet34(num_classes=1000, include_top=True):return ResNet(BasicBlock, [3, 4, 6, 3], num_classes=num_classes, include_top=include_top)def resnet101(num_classes=1000, include_top=True):return ResNet(Bottleneck, [3, 4, 23, 3], num_classes=num_classes, include_top=include_top)然后就可以在预测的时候输出中间层。
import torch
from alexnet_model import AlexNet
from resnet_model import resnet34
import matplotlib.pyplot as plt
import numpy as np
from PIL import Image
from torchvision import transformsdata_transform = transforms.Compose([transforms.Resize((224, 224)),transforms.ToTensor(),transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5))])# data_transform = transforms.Compose(
# [transforms.Resize(256),
# transforms.CenterCrop(224),
# transforms.ToTensor(),
# transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])])# create model
model = AlexNet(num_classes=5)
# model = resnet34(num_classes=5)
# load model weights
model_weight_path = "./AlexNet.pth" # "./resNet34.pth"
model.load_state_dict(torch.load(model_weight_path))
print(model)# load image
img = Image.open("../tulip.jpg")
# [N, C, H, W]
img = data_transform(img)
# expand batch dimension
img = torch.unsqueeze(img, dim=0)# forward
out_put = model(img)
for feature_map in out_put:# [N, C, H, W] -> [C, H, W]im = np.squeeze(feature_map.detach().numpy())# [C, H, W] -> [H, W, C]im = np.transpose(im, [1, 2, 0])# show top 12 feature mapsplt.figure()for i in range(12):ax = plt.subplot(3, 4, i+1)# [H, W, C]plt.imshow(im[:, :, i], cmap='gray')plt.show()输出卷积核的参数
import torch
from alexnet_model import AlexNet
from resnet_model import resnet34
import matplotlib.pyplot as plt
import numpy as np# create model
model = AlexNet(num_classes=5)
# model = resnet34(num_classes=5)
# load model weights
model_weight_path = "./AlexNet.pth" # "resNet34.pth"
model.load_state_dict(torch.load(model_weight_path))
print(model)weights_keys = model.state_dict().keys()
for key in weights_keys:# remove num_batches_tracked para(in bn)if "num_batches_tracked" in key:continue# [kernel_number, kernel_channel, kernel_height, kernel_width]weight_t = model.state_dict()[key].numpy()# read a kernel information# k = weight_t[0, :, :, :]# calculate mean, std, min, maxweight_mean = weight_t.mean()weight_std = weight_t.std(ddof=1)weight_min = weight_t.min()weight_max = weight_t.max()print("mean is {}, std is {}, min is {}, max is {}".format(weight_mean,weight_std,weight_max,weight_min))# plot hist imageplt.close()weight_vec = np.reshape(weight_t, [-1])plt.hist(weight_vec, bins=50)plt.title(key)plt.show()
)
