The MP3 file format was always encumbered with patents, but as of 2017, the last patent finally expired. Although the format became synonymous with the digital music revolution that started in the …
PNG is really designed for images that are either flat color or use an ordered dither. I mean, we do use it for photographs because it’s everywhere and lossless, but it was never really intended to compress photographs well.
There are formats that do aim for that, like lossless JPEG and one of the WebP variants.
TIFF also has some utility in that it’s got some sort of hierarchical variant that’s useful for efficiently dealing with extremely-large images, where software that deals with most other formats really falls over.
But none of those are as universally-available.
Also, I suppose that if you have a PNG image, you know that – well, absent something like color reduction – it was losslessly-compressed, whereas all of the above have lossless and lossy variants.
PNG is really designed for images that are either flat color or use an ordered dither. I mean, we do use it for photographs because it’s everywhere and lossless, but it was never really intended to compress photographs well.
There are formats that do aim for that, like lossless JPEG and one of the WebP variants.
TIFF also has some utility in that it’s got some sort of hierarchical variant that’s useful for efficiently dealing with extremely-large images, where software that deals with most other formats really falls over.
But none of those are as universally-available.
Also, I suppose that if you have a PNG image, you know that – well, absent something like color reduction – it was losslessly-compressed, whereas all of the above have lossless and lossy variants.