FocalLoss

focal loss caffe version

Usage

1. Update your caffe.proto and the code.
2. make -j4
3. usage of FocalLoss layer
   ```

   if your task is a 3-class classification problem

   layer{
   name: “loss”
   type: “FocalLoss”
   bottom: “feature”
   bottom: “label”
   top: “loss”
   include {

    phase: TRAIN

   }
   focal_loss_param {

    alpha_balance: true
    gamma: 2
    alpha: 0.5 #background
    alpha: 1
    alpha: 1

   }
   }

```

Derivation

Reference

Tsung-Yi Lin, Priya Goyal, Ross Girshick, Kaiming He, Piotr Dollár, Focal Loss for Dense Object Detection, Paper Link