#blurhash

fast-blurhash

A faster implementation of the BlurHash algorithm used to generate better looking placeholder for websites and mobile apps

2 stable releases

1.0.1 Mar 5, 2023
1.0.0 Mar 4, 2023

#1 in #blurhash

Apache-2.0

41KB
621 lines

Crates.io

Fast(er) BlurHash

A faster implementation of the BlurHash algorithm used to generate better looking placeholder for websites and mobile apps. This crates encode and decode functions minimizes the number of allocated vectors to reduce the memory footprint. The base83 encode and decode are also both very fast!

Credits

The original implementation of the BlurHash algorithm can be found here.

Usage

Installation

fast_blurhash is available on crates.io

Use the cargo add command:

cargo add fast_blurhash

or add the crate in your Cargo.toml:

[dependencies]
fast_blurhash = "1"

Generating a blurhash from an image

Generating a blurhash from an image:

use fast_blurhash::compute_dct;

let (width, height) = todo!("Get image width and height");
let image: Vec<u32> = todo!("Load the image");
let blurhash = compute_dct(&image, width, height, 3, 4).into_blurhash();

You can also pass a long-enough iterator to avoid copying data:

use fast_blurhash::compute_dct;

let (width, height) = todo!("Get image width and height");
let image: Vec<u32> = todo!("Load the image");
let blurhash = compute_dct_iter(image.iter(), width, height, 3, 4).into_blurhash();

Supported types to be used with compute_dct:

Type Alias Disposition Notes
[f32; 3] Linear [Red, Green, Blue] Channels are in linear space
[u8; 3], &[u8; 3] Rgb [Red, Green, Blue]
[u8; 4], &[u8; 4] Rgba [Red, Green, Blue, Alpha] Alpha is ignored
u32 0xAARRGGBB where A is alpha Alpha is ignored

This crate also supports using your custom types (see the trait AsLinear and examples in the documentation).

Generating a placeholder from a blurhash

Generating an image from a blurhash:

use fast_blurhash::decode;

let blurhash = "LlMF%n00%#MwS|WCWEM{R*bbWBbH";
let image: Vec<u32> = decode(&blurhash, 1.).unwrap().to_rgba(32, 32);

Available generation functions:

Function Return type Disposition Notes
to_image<\T>(width, height, fn(Linear) -> T) Vec<\T> Linear: [Red, Green, Blue] Linear is a builtin type that represents a color in linear space.
to_rgb8(width, height) Vec<[u8; 3]> [Red, Green, Blue]
to_rgba8(width, height) Vec<[u8; u4]> [Red, Green, Blue, Alpha] Alpha will always be 255
to_rgba(width, height) Vec<\u32> 0xAARRGGBB where A is alpha Alpha will always be 255

Documentation

More documentation is available in rust docs.

TODO

  • Add documentation
  • Add decode
  • Publish to crate.io

Contribution & Feedback

If you have any feedback, please open an issue. If you encounter any bugs or unwanted behaviour, please open an issue.

This projet is open to contributions, feel free to submit your pull requests!

License

fast-blurhash is available under the Apache License 2.0 license. See the LICENSE file for more info.

No runtime deps