AUTOMATIC1111
Upscale to jpg does not retain parameters
When you use the Extra tab and upscale a PNG file to a larger PNG file it retains the parameters
Original image:
parameters
a tree with a bird
Negative prompt: grass
Steps: 40, Sampler: Euler a, CFG scale: 7, Seed: 968002204, Size: 512x512
Becomes:
parameters
a tree with a bird
Negative prompt: grass
Steps: 40, Sampler: Euler a, CFG scale: 7, Seed: 968002204, Size: 512x512
extras
Upscale: 2, model:Lanczos
However when you upscale a JPG to JPG it changes the metadata.
Original image:
exif comment
a tree with a bird
Negative prompt: grass
Steps: 40, Sampler: Euler a, CFG scale: 7, Seed: 2378972195, Size: 512x512
Becomes:
exif comment
Upscale: 2, model:Lanczos
The same thing happens when you convert a PNG to JPG.
I would expect that upscale to JPG should still store the parameters in the metadata. I realize that the PNG and the JPG store the info differently and in different places. I imagine that it's more common upscale to a JPG as PNG get rather large quickly.
jpeg info seems not to be built up from existing_info in the same way the png info is:
https://github.com/AUTOMATIC1111/stable-diffusion-webui/blob/041d2aefc082c2883aa7e28ee3e4a990b3be9758/modules/images.py#L372-L379
PNG is really too big, JPG or WEBP file size is only 1/10 of png. Is there a solution now?
