Zqoi

QOI decoder/encoder written in pure Zig. Optimized for decoding speed.

Using

You will need:

• Zig compiler 0.16.0

Fetch:

zig fetch --save git+https://github.com/Pivok7/zqoi

In build.zig:

const zqoi = b.dependency("zqoi", .{
    .target = target,
    .optimize = optimize,
}).module("root");
exe.root_module.addImport("zqoi", zqoi);

Example:

const std = @import("std");
const zqoi = @import("zqoi");

pub fn main(init: std.process.Init) !void {
    const allocator = init.gpa;
    const io = init.io;

    // Load and save file
    {
        var img = try zqoi.Image.fromFilePath(allocator, io, "../image.qoi");
        defer img.deinit(allocator);

        try img.toFilePath(io, "copy.qoi");
    }

    // Manually create image
    {
        var img = zqoi.Image{
            .width = 1024,
            .height = 1024,
            .pixels = undefined,
            .format = .r8g8b8a8_srgb,
        };

        img.pixels = try allocator.alloc(zqoi.Rgba, img.width * img.height);
        defer allocator.free(img.pixels);

        for (img.pixels, 0..) |*pixel, i| {
            pixel.* = zqoi.Rgba{
                .r = @as(u8, @intCast(i % 256)),
                .g = @as(u8, @intCast(i % 128)),
                .b = @as(u8, @intCast(i % 64)),
                .a = 255,
            };
        }

        try img.toFilePath(io, "generated.qoi");
    }
}

Speed

You can run benchmarks yourself by following the instructions in the 'benchmark' directory.

Benchmarks performed on the images from https://qoiformat.org/benchmark/

CPU: AMD Ryzen 7 5700X

The results:

Encoding	zqoi	reference
textures_plants	3.60ms	4.2ms
screenshot_game	2.54ms	2.6ms
textures_pk02	1.82ms	1.8ms
photo_kodak	2.59ms	2.6ms
textures_pk01	0.66ms	0.7ms
icon_512	0.49ms	0.7ms
photo_tecnick	10.02ms	10.0ms
icon_64	0.01ms	0.0ms
textures_photo	6.45ms	6.1ms
textures_pk	0.33ms	0.3ms
screenshot_web	15.27ms	23.0ms
photo_wikipedia	7.71ms	7.6ms
pngimg	6.18ms	7.4ms
total	1.99ms	2.1ms

Decoding	zqoi	reference
textures_plants	2.07ms	2.7ms
screenshot_game	1.69ms	2.1ms
textures_pk02	1.23ms	1.4ms
photo_kodak	1.58ms	2.0ms
textures_pk01	0.41ms	0.5ms
icon_512	0.31ms	0.4ms
photo_tecnick	6.14ms	7.6ms
icon_64	0.01ms	0.0ms
textures_photo	3.97ms	5.1ms
textures_pk	0.18ms	0.2ms
screenshot_web	8.88ms	20.4ms
photo_wikipedia	4.62ms	5.8ms
pngimg	3.63ms	5.8ms
total	1.24ms	1.7ms