I am pleased to announce the release of a new library Blurhash 0.1.0!
This library implements an encoder for BlurHash in OCaml. BlurHash allows us to convert an image into a short string that represents a lightweight, ‘blurred’ version of the input image. It can be used as a placeholder on a Web page, for example.
The only function this library provides is Blurhash.blur_hash_for_pixels, which takes the same arguments as blurHashForPixels in the C reference implementation.
Although it does not depend on any image library, you can use (e.g.,) camlimages to load an image from a file.
let load_image_as_rgb24 ~path =
match OImages.(load path [] |> tag) with
| Rgb24 img -> img
| Rgba32 img -> img#to_rgb24
| Index8 img -> img#to_rgb24
| Index16 img -> img#to_rgb24
| Cmyk32 _ -> failwith "Not supported image type: Cmyk32"
let blurhash ~x_components ~y_components src =
Blurhash.blur_hash_for_pixels ~x_components ~y_components ~width:src#width
~height:src#height ~bytes_per_row:(src#width * 3) src#dump
let test_encode_case1 () =
let src = load_image_as_rgb24 ~path:"../../../test/test.ppm" in
let hash = blurhash ~x_components:4 ~y_components:3 src in
Alcotest.(check string) "test1" "LFE.@D9F01_2%L%MIVD*9Goe-;WB" hash;
()