We propose a semantic segmentation model that exploits rotation and reflection symmetries. We demonstrate significant gains in sample efficiency due to increased weight sharing, as well as improvements in robustness to symmetry transformations. The group equivariant CNN framework is extended for segmentation by introducing a new equivariant (G->Z2)-convolution that transforms feature maps on a group to planar feature maps. Also, equivariant transposed convolution is formulated for up-sampling in an encoder-decoder network. To demonstrate improvements in sample efficiency we evaluate on multiple data regimes of a rotation-equivariant segmentation task: cancer metastases detection in histopathology images. We further show the effectiveness of exploiting more symmetries by varying the size of the group.

我们提出了一种语义分割模型，利用旋转和反射对称性，扩展了等变CNN框架，通过引入新的等变（G-》Z2）-卷积和等变转置卷积，实现了对组别特征图的变换与上采样，进而提高了样本效率和鲁棒性，并在癌症转移组织病理图像的多个数据组织方案的旋转等变分割任务上进行了评估，证明了利用更多对称性的高效性。

使用旋转等变卷积网络进行高效语义分割