To decide where to crop an image, how can I highlight it's most compressible areas?
- by Umber Ferrule
I'm looking to get the most compression out of each of the most popular image formats, such as, JPEG, PNG, GIF, etc.
Ideally, this would be a tool, or a series of transforms that could be performed (perhaps using a macro and then discarded) in popular image editors (Paint.NET/PaintShopPro/PhotoShop/GIMP) to highlight areas which will compress less.
Alternatively, what rules of thumb can be used other than reducing colours (for PNG/GIF), reducing image dimensions, avoiding high detail areas...
I'm not asking for help deciding what format to use for a particular image type as I think this is fairly common knowledge, i.e. diagram and images with few colours = PNG/GIF, photographs = JPEG.