【图像分割 损失函数】Loss functions for image segmentation

损失函数

Github

Github

Dice

class SoftDiceLoss(nn.Module):
    def __init__(self, smooth=1., dims=(-2,-1)):

        super(SoftDiceLoss, self).__init__()
        self.smooth = smooth
        self.dims = dims
    
    def forward(self, x, y):

        tp = (x * y).sum(self.dims)
        fp = (x * (1 - y)).sum(self.dims)
        fn = ((1 - x) * y).sum(self.dims)
        
        dc = (2 * tp + self.smooth) / (2 * tp + fp + fn + self.smooth)
        dc = dc.mean()

        return 1 - dc