基于轻量级GhostNet模型开发构建生活场景下生活垃圾图像识别系统

轻量级识别模型在我们前面的博文中已经有过很多实践了，感兴趣的话可以自行移步阅读：

本文的核心思想是像基于GhostNet来开发构建生活场景下的生活垃圾图像识别系统，首先看下实例效果：

GhostNet 是一种轻量级卷积神经网络，是专门为移动设备上的应用而设计的。其主要构件是 Ghost 模块，一种新颖的即插即用模块。Ghost 模块设计的初衷是使用更少的参数来生成更多特征图 (generate more features by using fewer parameters)。

官方论文地址在这里，如下所示：

官方也开源了项目，地址在这里，如下所示：

可以详细阅读官方的代码实例即可，之后可以基于自己的数据集来开发构建模型即可。

这里给出GhostNet的核心实现部分，如下所示：

python 复制代码

class GhostNet(nn.Module):
    def __init__(self, cfgs, num_classes=1000, width_mult=1.0):
        super(GhostNet, self).__init__()
        self.cfgs = cfgs
        output_channel = _make_divisible(16 * width_mult, 4)
        layers = [
            nn.Sequential(
                nn.Conv2d(3, output_channel, 3, 2, 1, bias=False),
                nn.BatchNorm2d(output_channel),
                nn.ReLU(inplace=True),
            )
        ]
        input_channel = output_channel
        block = GhostBottleneck
        for k, exp_size, c, use_se, s in self.cfgs:
            output_channel = _make_divisible(c * width_mult, 4)
            hidden_channel = _make_divisible(exp_size * width_mult, 4)
            layers.append(
                block(input_channel, hidden_channel, output_channel, k, s, use_se)
            )
            input_channel = output_channel
        self.features = nn.Sequential(*layers)
        output_channel = _make_divisible(exp_size * width_mult, 4)
        self.squeeze = nn.Sequential(
            nn.Conv2d(input_channel, output_channel, 1, 1, 0, bias=False),
            nn.BatchNorm2d(output_channel),
            nn.ReLU(inplace=True),
            nn.AdaptiveAvgPool2d((1, 1)),
        )
        input_channel = output_channel
        output_channel = 1280
        self.classifier = nn.Sequential(
            nn.Linear(input_channel, output_channel, bias=False),
            nn.BatchNorm1d(output_channel),
            nn.ReLU(inplace=True),
            nn.Dropout(0.2),
            nn.Linear(output_channel, num_classes),
        )
        self._initialize_weights()
 
    def forward(self, x, need_fea=False):
        if need_fea:
            features, features_fc = self.forward_features(x, need_fea)
            x = self.classifier(features_fc)
            return features, features_fc, x
        else:
            x = self.forward_features(x)
            x = self.classifier(x)
            return x
 
    def forward_features(self, x, need_fea=False):
        if need_fea:
            input_size = x.size(2)
            scale = [4, 8, 16, 32]
            features = [None, None, None, None]
            for idx, layer in enumerate(self.features):
                x = layer(x)
                if input_size // x.size(2) in scale:
                    features[scale.index(input_size // x.size(2))] = x
            x = self.squeeze(x)
            return features, x.view(x.size(0), -1)
        else:
            x = self.features(x)
            x = self.squeeze(x)
            return x.view(x.size(0), -1)
 
    def _initialize_weights(self):
        for m in self.modules():
            if isinstance(m, nn.Conv2d):
                nn.init.kaiming_normal_(m.weight, mode="fan_out", nonlinearity="relu")
            elif isinstance(m, nn.BatchNorm2d):
                m.weight.data.fill_(1)
                m.bias.data.zero_()
 
    def cam_layer(self):
        return self.features[-1]