README.md

php-imagebw

PHP Functions for converting image to greyscale and to black and white.

Usage

Simply include imagebw.php in your project and start using imagegreyscale and imagebw functions - see docs below.

Function docs

/**
 * Converts image to greyscale
 * @param resource|GdImage $img
 */
function imagegreyscale($img): void;

/**
 * Converts image to black and white image
 * @param resource|GdImage $img
 * @param int $type See BW_ constants
 */
function imagebw($img, int $type): void;

Methods of black and white conversion - BW_ constants

For second parameter of imagebw a $type of conversion is needed.

You can use following constants:

/**
 * Nearest color
 */
define("BW_NORMAL", 0);
/**
 * Floyd/Steinenberg
 */
define("BW_FLOID", 1);
/**
 * Stucki
 */
define("BW_STUCKI", 2);
/**
 * Burkes
 */
define("BW_BURKES", 3);
/**
 * Bayer
 */
define("BW_BAYER", 4);

License

The library is licensed under GNU/LGPL v2.1, see LICENSE for details.

Author

Jindra Petřík aka JPEXS

Changelog

Changes in versions are logged in the file CHANGELOG.md