Color Thief PHP

A PHP class for grabbing the color palette from an image. Uses PHP and GD or Imagick libraries to make it happen.

It's a PHP port of the Color Thief Javascript library, using the MMCQ (modified median cut quantization) algorithm from the Leptonica library.

See examples

Requirements

• PHP >= 5.4 or >= PHP 7.0
• One or more PHP extensions for image processing:
  • GD >= 2.0
  • Imagick >= 2.0 (but >= 3.0 for CMYK images)
  • Gmagick >= 1.0
• Supports JPEG, PNG and GIF images.

How to use

Install via Composer

The recommended way to install Color Thief is through Composer:

composer require ksubileau/color-thief-php

Get the dominant color from an image

require_once 'vendor/autoload.php';
use ColorThief\ColorThief;
$dominantColor = ColorThief::getColor($sourceImage);

The $sourceImage variable must contain either the absolute path of the image on the server, a URL to the image, a GD resource containing the image, an Imagick image instance, a Gmagick image instance, or an image in binary string format.

ColorThief::getColor($sourceImage[, $quality=10, $area=null])
returns array(r: num, g: num, b: num)

This function returns an array of three integer values, corresponding to the RGB values (Red, Green & Blue) of the dominant color.

You can pass an additional argument ($quality) to adjust the calculation accuracy of the dominant color. 1 is the highest quality settings, 10 is the default. But be aware that there is a trade-off between quality and speed/memory consumption ! If the quality settings are too high (close to 1) relative to the image size (pixel counts), it may exceed the memory limit set in the PHP configuration (and computation will be slow).

You can also pass another additional argument ($area) to specify a rectangular area in the image in order to get dominant colors only inside this area. This argument must be an associative array with the following keys :

• $area['x'] : The x-coordinate of the top left corner of the area. Default to 0.
• $area['y'] : The y-coordinate of the top left corner of the area. Default to 0.
• $area['w'] : The width of the area. Default to the width of the image minus x-coordinate.
• $area['h'] : The height of the area. Default to the height of the image minus y-coordinate.

Build a color palette from an image

In this example, we build an 8 color palette.

require_once 'vendor/autoload.php';
use ColorThief\ColorThief;
$palette = ColorThief::getPalette($sourceImage, 8);

Again, the $sourceImage variable must contain either the absolute path of the image on the server, a URL to the image, a GD resource containing the image, an Imagick image instance, a Gmagick image instance, or an image in binary string format.

ColorThief::getPalette($sourceImage[, $colorCount=10, $quality=10, $area=null])
returns array(array(num, num, num), array(num, num, num), ... )

The $colorCount argument determines the size of the palette; the number of colors returned. If not set, it defaults to 10.

The $quality and $area arguments work as in the previous function.

Credits and license

Author

by Kevin Subileau kevinsubileau.fr

Based on the fabulous work done by Lokesh Dhakar lokeshdhakar.com twitter.com/lokesh

Thanks

• Lokesh Dhakar - For creating the original project.
• Nick Rabinowitz - For creating quantize.js.

License

Licensed under the Creative Commons Attribution 2.5 License

• Free for use in both personal and commercial projects.
• Attribution requires leaving author name, author homepage link, and the license info intact.