Recently, channel attention mechanism has demonstrated to offer great potential in improving the performance of deep convolutional neural networks (CNNs). However, most existing methods dedicate to developing more sophisticated attention modules for achieving better performance, which inevitably increase model complexity. To overcome the paradox of performance and complexity trade-off, this paper proposes an Efficient Channel Attention (ECA) module, which only involves a handful of parameters while bringing clear performance gain. By dissecting the channel attention module in SENet, we empirically show avoiding dimensionality reduction is important for learning channel attention, and appropriate cross-channel interaction can preserve performance while significantly decreasing model complexity. Therefore, we propose a local cross-channel interaction strategy without dimensionality reduction, which can be efficiently implemented via 1D convolution. Furthermore, we develop a method to adaptively select kernel size of 1D convolution, determining coverage of local cross-channel interaction. The proposed ECA module is efficient yet effective, e.g., the parameters and computations of our modules against backbone of ResNet50 are 80 vs. 24.37M and 4.7e-4 GFLOPs vs. 3.86 GFLOPs, respectively, and the performance boost is more than 2% in terms of Top-1 accuracy. We extensively evaluate our ECA module on image classification, object detection and instance segmentation with backbones of ResNets and MobileNetV2. The experimental results show our module is more efficient while performing favorably against its counterparts.
近来，通道注意力机制已经被证明可以极大的提升深度卷积神经网络的性能。但是现有的方法为了获得更好的性能往往采用更为复杂的注意力模型因此反而增加了模型的复杂度。为了解决性能和计算复杂度的平衡，本文提出了高效通道注意力模块 (ECA) 使得使用较少的参数而可以获得明显的性能提升。通过研究SENet的通道注意力模型，我们从经验上推论减少维度对于学习通道注意力至关重要，适当的通道间交互可以在保持性能的同时极大地提高模型的复杂度。因此我们提出了一种通过一维卷积实现的本地跨通道交互策略而不需要减少维度。另外，我们还提出一种自适应选择一维卷积核尺寸的方法以衡量通道之间的交互的程度。ECA模块相较于基本的RseNet50有较大提升并可以用于多种如图像识别，目标检测以及实例分割等以ResNet和MobileNetV2为框架的任务中。