eblurhash - Blurhash for Erlang

This is an Erlang version of https://blurha.sh

A blurhash is a compact string with encoded colors to show a blurred version of an image before the image itself is loaded.

With ImageMagick

Use the magick function to first let imagemagick resize (and secure) the image, before using the blurhash program to calculate the hash.

eblurhash:magick("path/to/image.jpg").

Return something like:

{ok, <<"MlMF%n00%#Mwo}S|WCWEM{a$R*bbWBbHfl">>}

Note: you will need to have ImageMagick installed

The magick command checks the image size and selects optimal X and Y size for the blurhash. Where X and Y are in the range 1..5.

The command line program convert is used to convert the image to a smaller gif file. This gif file is then provided to the blurhash program.

Using blurhash directly

This uses the C version of blurhash on the supplied image file.

The C version uses stb_image to load images, which is not security-hardened, so it is not recommended to use this version in production on untrusted data!

The blurhash command needs to have the X and Y arguments provided:

eblurhash:hash(5, 3, "path/to/image.jpg").

Returns {ok, <<"...">>} or {error, Reason}.