Metrics module for chuchichaestli

[phdenzel]

Let's discuss if this would be helpful for everyone... Easy metrics would be (in 2D/3D):

• PSNR
• SSIM

A bit more complicated and specialized:

• Perceptual/feature metrics

[phdenzel]

For images we can bootstrap https://github.com/Lightning-AI/torchmetrics/tree/master/src/torchmetrics/image. For volumes some from torchmetrics might work, most probably won't... but at least we have a starting point. Also, some 3D metrics can be found in the MONAI repository: https://github.com/Project-MONAI/MONAI/tree/dev/monai/metrics.

[phdenzel]

We could combine losses and metrics. For latent diffusion we also need

• LPIPS https://github.com/CompVis/taming-transformers/blob/3ba01b241669f5ade541ce990f7650a3b8f65318/taming/modules/losses/lpips.py#L11 https://github.com/CAIIVS/chuchichaestli/issues/59
• PatchGAN loss https://github.com/CAIIVS/chuchichaestli/issues/55#issue-2694029038

[danielbarco]

For the FD (incl. FID) with different backbones, I am working on this issue: https://github.com/CAIIVS/chuchichaestli/issues/60