alt Hacker NewsThe difference between valid PNG you can't decompress and invalid PNG is fairly irrelevant when your aim is to get an image onto the screen.
And considering we already have plenty of more advanced competing lossless formats, I really don't see why "feed a BMP to deflate" needs a new, incompatible spin in 2025.
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fc417fc802 • yesterday at 7:42 AM
> plenty of more advanced competing lossless formats
Other than JXL which still has somewhat spotty support in older software? TIFF comes to mind but AFAIK its size tends to be worse than PNG. Edit: Oh right OpenEXR as well. How widespread is support for that in common end user image viewer software though?
It's a new and compatible spin. https://svgees.us/blog/img/revoy-cICP-bt.2020.png uses the important new feature and your old software can display it.
More generally, PNG has a simple feature to specify what's needed. A file consists of a number of chunks, and one bit in the chunk specifies whether that chunk is required for display. All of the extensions I've seen in the past decades set that bit to "optional".
For example, this update includes a chunk containing EXIF data. As you'd expect, the exif chunk sets that bit to "optional".