Society doesn't need a new image format. I'd wager to say not any new multimedia format. Big corporate entites do, and have churning them out at a steady pace.
Look at poor webp - a format pushed by the largest industry players - and the abysmal everyday use it gets, and the hate it generates.
They say it's technically compatible since older image decoders should recognize the PNG file is using a different compression algorithm than the default.
> Many programs already support the new PNG spec: Chrome, Safari, Firefox, iOS/macOS, Photoshop, DaVinci Resolve, Avid Media Composer...
This is intentionally ignoring the fact that there are countless PNG decoders out in the wild, many using libpng the standard decoder last updated 6 years ago; and they will not be able to read the new PNG v2 files.
They should have used a different file extension, PNG2, to distinguish this incompatible format. Otherwise, users will be confused why their newly saved PNG file cannot be read by certain existing programs.
To start, there's a byte with the upper bit set which ensures an "8-bit clean" transport. If it's stripped, it becomes a harmless tab. Then the literal "PNG" text so you can see it in a text editor. Then a CR-LF pair to check for CR-LF to LF translations. Then, a CTRL-Z to stop display on DOS-like systems. And finally, another LF to check for LF to CR-LF translations.
It's a clever "magic" that basically ensures a binary transport layer. Things that mattered back in 1996.
https://www.libpng.org/pub/png/spec/1.2/PNG-Rationale.html#R...
