This document describes PNG (Portable Network Graphics), an extensible file format for the lossless, portable,
well-compressed storage of static and animated raster images. PNG provides a patent-free replacement for GIF and can also
replace many common uses of TIFF. Indexed-color, greyscale, and truecolor images are supported, plus an optional alpha
channel. Sample depths range from 1 to 16 bits.
What a weird take. Alpha channels are used all the time. A lot of tools use WebP for them, though. Things like stickers and emoji in chat apps often recode into WebP or force you to figure out how to make a WebP with a certain configuration to accept your pack, but from there on out they rely on alpha channels.
MacOS app icons are a collection of layers with alpha channels embedded into them, stacked on top of each other, or themed individually. Unless you’re blind, any iOS or macOS user encounters alpha channels every time they turn on their screen. On Android, those files are even actual PNGs. On Windows, those are .ico resources, and everything larger than 64x64 is guaranteed to be a PNG embedded inside of an .ico (possibly embedded inside of a .exe/.dll/etc.
WebP has replaced jpeg for most web content already when it comes to compression. This just solves things like “how do I save my HDR images without degrading them every time I hit save”.
What a weird take. Alpha channels are used all the time. A lot of tools use WebP for them, though. Things like stickers and emoji in chat apps often recode into WebP or force you to figure out how to make a WebP with a certain configuration to accept your pack, but from there on out they rely on alpha channels.
MacOS app icons are a collection of layers with alpha channels embedded into them, stacked on top of each other, or themed individually. Unless you’re blind, any iOS or macOS user encounters alpha channels every time they turn on their screen. On Android, those files are even actual PNGs. On Windows, those are .ico resources, and everything larger than 64x64 is guaranteed to be a PNG embedded inside of an .ico (possibly embedded inside of a .exe/.dll/etc.
WebP has replaced jpeg for most web content already when it comes to compression. This just solves things like “how do I save my HDR images without degrading them every time I hit save”.
I’ll agree for those use cases, but not everyone is making icons, stickers and emoji.
They are using them, however. They’re visiting websites with them, using apps with them, and so forth.
OK, and the kernel is written in C and assembly. Should they know both of those as well?
No, but it should still work. Getting rid of alpha channels would break all of that.