psp_net.py 文件源码

def __init__(self, num_classes, pretrained=True, use_aux=True):
        super(PSPNet, self).__init__()
        self.use_aux = use_aux
        resnet = models.resnet101()
        if pretrained:
            resnet.load_state_dict(torch.load(res101_path))
        self.layer0 = nn.Sequential(resnet.conv1, resnet.bn1, resnet.relu, resnet.maxpool)
        self.layer1, self.layer2, self.layer3, self.layer4 = resnet.layer1, resnet.layer2, resnet.layer3, resnet.layer4

        for n, m in self.layer3.named_modules():
            if 'conv2' in n:
                m.dilation, m.padding, m.stride = (2, 2), (2, 2), (1, 1)
            elif 'downsample.0' in n:
                m.stride = (1, 1)
        for n, m in self.layer4.named_modules():
            if 'conv2' in n:
                m.dilation, m.padding, m.stride = (4, 4), (4, 4), (1, 1)
            elif 'downsample.0' in n:
                m.stride = (1, 1)

        self.ppm = _PyramidPoolingModule(2048, 512, (1, 2, 3, 6))
        self.final = nn.Sequential(
            nn.Conv2d(4096, 512, kernel_size=3, padding=1, bias=False),
            nn.BatchNorm2d(512, momentum=.95),
            nn.ReLU(inplace=True),
            nn.Dropout(0.1),
            nn.Conv2d(512, num_classes, kernel_size=1)
        )

        if use_aux:
            self.aux_logits = nn.Conv2d(1024, num_classes, kernel_size=1)
            initialize_weights(self.aux_logits)

        initialize_weights(self.ppm, self.final)