README

A PHP class for grabbing the color palette from an image. Uses PHP and GD, Imagick or Gmagick 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 >= 7.2 or >= PHP 8.0
• Fileinfo extension
• 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, GIF and WEBP 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, $outputFormat='array', $adapter = null])

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.

By default, color is returned as an array of three integers representing red, green, and blue values. You can choose another output format by passing one of the following values to the $outputFormat argument :

• rgb : RGB string notation (ex: rgb(253, 42, 152)).
• hex : String of the hexadecimal representation (ex: #fd2a98).
• int : Integer color value (ex: 16591512).
• array : Default format (ex: array[253, 42, 152]).
• obj : Instance of ColorThief\Color, for custom processing.

The optional $adapter argument lets you choose a preferred image adapter to use to load the image. By default, the adapter is automatically chosen based on the available extensions and the type of $sourceImage (e.g. Imagick is used if $sourceImage is an Imagick instance). You can pass one of the Imagick, Gmagick or Gd string to force the use of the corresponding underlying image extension. For advanced usage, you can even pass an instance of any class implementing the AdapterInterface interface to use a custom image loader.

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, $outputFormat='array', $adapter = null])

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

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

Credits

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.