JPEG Filesize Overkill

This problem definitely isn't as common as png overkill, but I think it should be addressed in some way.

A prime example of jpeg overkill would be this pool:
http://danbooru.donmai.us/pool/show/974

The first image in the pool, a 2.3 megabyte jpeg, can be saved as a 300 kilobyte png. Another example would be post #616416, where saving the image as png reduces filesize by nearly 50%.

There's no reason to upload the smaller png at this point, so this thread is about future posts involving such images.

A lot of grayscale images can be smaller when saved as png, even if the original had jpeg artifacts. I think that users uploading black and white comics and similar images should be encouraged to check to see if the image is actually smaller as png. It takes a small amount of time to do and it could help reduce some of the strain on the servers.

I suppose a problem with this could be that the source is a jpeg while the image itself is a png, but that doesn't seem like a huge deal to me. I'm also not sure if it would affect the image duplicate checker.

CaptainCappy said:
...and it could help reduce some of the strain on the servers.

I highly doubt that. Those types of images are pretty rare to begin with from what I can tell, so there would really be no change at all.

And yes, it will mess with the dupe checker since the resaved image would have a different MD5 hash. The only way to avoid a dupe in that case would involve using the Find Similar button, which, sadly, isn't used all that often anyways.

Just upload the image from the source as it is and leave at that.

Ars is correct. The biggest strain on the servers is definitely not bandwidth from viewing/downloading images, it's SQL queries from doing searches, viewing profile pages, or doing pretty much anything else on the site.