mindspore densenet代码

以下是用MindSpore实现DenseNet的代码：

import mindspore.nn as nn
from mindspore.ops import operations as P


class DenseLayer(nn.Cell):
    def __init__(self, in_channels, growth_rate):
        super(DenseLayer, self).__init__()
        self.conv = nn.Conv2d(in_channels=in_channels, out_channels=growth_rate, kernel_size=3, padding=1, has_bias=False)
        self.relu = nn.ReLU()
        self.concat = P.Concat(axis=1)

    def construct(self, x):
        out = self.conv(x)
        out = self.relu(out)
        out = self.concat((x, out))
        return out


class DenseBlock(nn.Cell):
    def __init__(self, in_channels, growth_rate, num_layers):
        super(DenseBlock, self).__init__()
        self.layers = nn.SequentialCell()
        for i in range(num_layers):
            self.layers.append(DenseLayer(in_channels + i * growth_rate, growth_rate))

    def construct(self, x):
        out = x
        for layer in self.layers:
            out = layer(out)
        return out


class TransitionLayer(nn.Cell):
    def __init__(self, in_channels, out_channels):
        super(TransitionLayer, self).__init__()
        self.conv = nn.Conv2d(in_channels=in_channels, out_channels=out_channels, kernel_size=1, has_bias=False)
        self.avg_pool = nn.AvgPool2d(kernel_size=2, stride=2)
        self.relu = nn.ReLU()

    def construct(self, x):
        out = self.conv(x)
        out = self.avg_pool(out)
        out = self.relu(out)
        return out


class DenseNet(nn.Cell):
    def __init__(self, num_classes=10, growth_rate=12, block_config=(6, 12, 24, 16)):
        super(DenseNet, self).__init__()

        self.conv = nn.Conv2d(in_channels=3, out_channels=2 * growth_rate, kernel_size=3, padding=1, has_bias=False)
        self.relu = nn.ReLU()
        self.pool = nn.MaxPool2d(kernel_size=3, stride=2, pad_mode='same')

        self.dense_block1 = DenseBlock(2 * growth_rate, growth_rate, block_config[0])
        in_channels1 = 2 * growth_rate + block_config[0] * growth_rate
        out_channels1 = in_channels1 // 2
        self.trans_layer1 = TransitionLayer(in_channels1, out_channels1)

        self.dense_block2 = DenseBlock(out_channels1, growth_rate, block_config[1])
        in_channels2 = out_channels1 + block_config[1] * growth_rate
        out_channels2 = in_channels2 // 2
        self.trans_layer2 = TransitionLayer(in_channels2, out_channels2)

        self.dense_block3 = DenseBlock(out_channels2, growth_rate, block_config[2])
        in_channels3 = out_channels2 + block_config[2] * growth_rate
        out_channels3 = in_channels3 // 2
        self.trans_layer3 = TransitionLayer(in_channels3, out_channels3)

        self.dense_block4 = DenseBlock(out_channels3, growth_rate, block_config[3])
        in_channels4 = out_channels3 + block_config[3] * growth_rate

        self.avg_pool = nn.AvgPool2d(kernel_size=8)
        self.flatten = nn.Flatten()
        self.fc = nn.Dense(in_channels4, num_classes)

    def construct(self, x):
        out = self.conv(x)
        out = self.relu(out)
        out = self.pool(out)

        out = self.dense_block1(out)
        out = self.trans_layer1(out)

        out = self.dense_block2(out)
        out = self.trans_layer2(out)

        out = self.dense_block3(out)
        out = self.trans_layer3(out)

        out = self.dense_block4(out)

        out = self.avg_pool(out)
        out = self.flatten(out)
        out = self.fc(out)

        return out

这是一个包含了DenseNet各个模块的代码，其中包括了DenseLayer、DenseBlock、TransitionLayer和DenseNet等模块的实现。然后，我们可以通过实例化DenseNet并传入相应的参数来构建模型。