# 关于弱监督一些记录

Posted by kevin on December 6, 2020

## 关于 CAM 系列

### CAM

CAM 里面，在经过 softmax 之前的某类别得分为如下公式

### Grad-CAM

Z 是 feature map 上的所有像素点个数，这其实做的是跟 GAP 相似的事情，所以最后得到的 Grad-CAM map 用如下公式表示

### CAM关注显著区域的解决方案

To alleviate this problem, Wei et al. (Wei et al. 2017a) propose to adopt an iterative erasing strategy. MDC (Wei et al. 2018) proposes to merge multiple CAMs with different dilation rates. DSRG (Huang et al. 2018) proposes to dynamically fill in the sparse seeds by region growing. Wang et al. (Wang et al. 2018) propose to alternately train a superpixel based classification network and the segmentation network. Other works (Briq, Moeller, and Gall 2018; Kolesnikov and Lampert 2016) propose some heuristic constraints. The concurrent work FickleNet (Lee et al. 2019) randomly drops connections in each sliding window. Although these methods are effective, they ignore the rich relationships across different images, while we prove that the cross-image relationship is effective for obtaining consistent and integral regions for weakly supervised segmentation.