README

Thumbhash PHP is a PHP library for generating unique, human-readable identifiers from image files. It is inspired by Evan Wallace's Thumbhash algorithm and provides a PHP implementation of the algorithm.

Thumbhash is a very compact representation of a placeholder for an image. Store it inline with your data and show it while the real image is loading for a smoother loading experience. It's similar to BlurHash but with some advantages

Read more and test it here !

Installation

You can install Thumbhash PHP using Composer:

composer require srwiez/thumbhash

⚠️ I highly recommend to have Imagick extension installed on your computer. GD extension has only 7 bits of alpha channel resolution, and 127 is transparent, 0 opaque. While the library will still work, you may have different image between platforms. See on stackoverflow

Usage

To generate a thumbhash for an image file, you can use the Thumbhash\Thumbhash class:

Example to show a thumbhash image from a local file

use Thumbhash\Thumbhash;

$content = file_get_contents($url);

list($width, $height, $pixels) = extract_size_and_pixels_with_imagick($content);

$hash = Thumbhash::RGBAToHash($width, $height, $pixels);
$key = Thumbhash::convertHashToString($hash); // You can store this in your database as a string
$url = Thumbhash::toDataURL($hash);

echo '<img src="' . $url . '" />';

Note

Like the original library implementation, your image must not exceed 100x100 pixels.

Credits

Thumbhash PHP was created by Eser DENIZ.

It is inspired by the javascript version of Evan Wallace's Thumbhash algorithm.

License

Thumbhash PHP is licensed under the MIT License. See LICENSE for more information.