About the normalization for Inception v3 when calculating FID

[AtsukiOsanai]

Thank you for sharing your excellent work!

I'm curious as to why you chose to re-normalize the fake images in this section. Considering that Inception v3 requires input values within [-1, 1], the generated fake images on this line already meet the requirement of inception v3. Therefore, I believe that re-normalizing these images could potentially result in an incorrect FID score if you're using a pre-trained Inception v3 model from torchvision.

From what I understand, re-normalization of the tensor is necessary only when we employ standard normalization as per ImageNet statistics, like in this ImageNet training example.

I hope you will clarify this issue to achieve a fair comparison in image synthesis.