Perceptual Loss in MAISI

[aolivtous]

First of all, thank you for your excellent work on the MAISI repository! I have a quick question regarding the LPIPS perceptual loss. From what I understand, LPIPS expects images to be normalized within a range of -1 to 1, but in the MAISI paper, it's mentioned that the images are normalized to a range of 0 to 1. I've seen a flag in the LPIPS forward (Normalize) that could be set to True, but by default it is False. Could you clarify this? Additionally, when training the MAISI VAE, if the reconstruction falls outside the [0, 1] range, shouldn't it be clipped before computing the perceptual loss?

[Can-Zhao]

Thank you very much! Yes, nice catch! It should be set as normalize=True in VAE training. Luckily, images with range [0,1] can still produce a reasonable feature through LPIPS as the pretrained squeeze network can take a broader range. We will make sure to set it as normalize=True in the next version of VAE training and add clipping to it

[aolivtous]

Thanks for your quick response! It's great to hear you'll update it in the next version.