png-decoder

Over a winter break a few years ago I wrote a PNG decoder in Rust, it was kinda fun! Here's the code if anyone's interested, it's not particularly great though. https://github.com/bschwind/png-decoder

> I'm curious if it is at all competitive with the Wuffs decoder You could try adapting https://github.com/google/wuffs/tree/main/script/bench-rust-... > https://github.com/bschwind/png-decoder Note that statements like: let bytes_per_scanline = ((header.width * header.bit_depth as u32 * header.color_type.sample_multiplier()) + 7) / 8; can silently overflow a u32 if width is 0x800_0000, bit_depth is 8 and sample_multiplier is 4. Part of the point of Wuffs is to catch things like that (at compile time).

I recently wrote a Rust PNG decoder mostly for use in no_std contexts, and it was motivated out of wanting to decode emoji for a font rasterizer. I didn't really put any effort into optimizing it yet, though it does use miniz_oxide and it decompresses the entire image at once instead of per-scanline. I'm curious if it is at all competitive with the Wuffs decoder, I'm guessing probably not because I haven't put any effort into using SIMD. https://github.com/bschwind/png-decoder But overall the implementation was pretty straightforward, I just read the RFC and wrote it out over a few weeks. One quirk of my library currently is it always returns an RGBA buffer, instead of potentially letting you save memory on a grayscale or RGB image.