Can you recommend a library for measuring image similarity?

I’m using PSNR recently.

However, the PSNR shows a low PSNR value even though the photos are more similar.

I think these problems are the downsides of PSNR.

Can you recommend an image similarity measurement method that improves the PSNR problem?

In general, PSNR may not be a good metric for most natural image domains. To measure perceptual similarity between images, may be an alternative method could be the structural similarity index
To go even farther, you could use inception distance as a sort of semantic similarity metric, similar to how it is used in FID scoring for Image GANs, Fréchet inception distance - Wikipedia.

Thank for your recommand I’m try it