colorize.php

<?php
/**
 * colorize
 * Jesse Baird
 <jebaird@gmail.com>
 * 9/21/2010
 *
 * Dual licensed under the MIT (MIT-LICENSE.txt)
 * and GPL (GPL-LICENSE.txt) licenses.
 *
 * simple php class to manipulate colors in an iamge and replace them
 *
 * http://stackoverflow.com/questions/456044/can-i-swap-colors-in-image-using-gd-library-in-php
 * http://php.net/manual/en/function.imagefilter.php
 * http://stackoverflow.com/questions/254388/how-do-you-convert-an-image-to-black-and-white-in-php
 * 
 * TODO: remove save from repalace and tint add method called save. only modify the image resosources in memory allowing you to do multipule "passes / calls on your set of images"
 *
 **/
class colorize {

	private $images = array();

	const CACHE_PATH = './cache/';

	/**
	 * colorizer::__construct()
	 *
	 * @param mixed $images array of iamges and paths | directory path
	 * @return void
	 */
	public function __construct($images = array()) {
		//check for directory
		if (is_string($images)) {
			$path = $images;
			if( substr($path, -1) != '/' ){
				$path.='/';
			}
			
			$images = array();
			
			if (is_dir($path)) {
				
				if ($dh = opendir($path)) {
					
					while (($file = readdir($dh)) !== false) {
						
						$ext = $this -> getExtention($file);
						//find all of the images in the path
						if (in_array($ext, array('png', 'gif', 'jpg', 'jpeg'))) {
							$images[] = $path.$file;
						}
					}
					closedir($dh);
					unset($dh, $file, $ext);
					// free memory
					//print_r( $images );
				}

			}

		}

		foreach ($images as $img) {
			$this -> images[basename($img)] = $this -> createImage($img);
		}
		unset($img);
	}

	/**
	 * colorizer::tint()
	 *
	 * tint all non-trasparent pixels in the supplied images with color
	 * @since 8/10/2011
	 * @author Jesse Baird
	 <jebaird@gmail.com>
	 * @param mixed $tint
	 * @param mixed $opacity
	 * @param string $fileNamePrefix
	 * @return void
	 */
	public function tint($tint = 0000000, $opacity = 0, $fileNamePrefix = '') {
		$tint = $this -> hexToRGB($tint);

		foreach ($this->images as $filename => $img) {

			imagefilter($img, IMG_FILTER_COLORIZE, $tint['r'], $tint['g'], $tint['b'], $opacity);

			$this -> saveImage((($fileNamePrefix != '') ? $fileNamePrefix . '_' : '') . $filename, $img);
			imagedestroy($img);
		}
	}

	/**
	 * colorizer::replace()
	 *
	 * find all colors in images and replace them
	 *
	 * @param mixed $find
	 * @param mixed $replace
	 * @param string $fileNamePrefix
	 * @return void
	 */
	public function replace($find = 000000, $replace = 000000, $fileNamePrefix = '') {
		$frgb = $rrgb = array();
		if (is_array($find)) {
			foreach ($find as $c) {
				$frgb[] = $this -> hexToRGB($c);
			}
		} else {
			$frgb[] = $this -> hexToRGB($find);
		}

		if (is_array($replace)) {
			foreach ($replace as $c) {
				$rrgb[] = $this -> hexToRGB($c);
			}
		} else {
			$rrgb[] = $this -> hexToRGB($replace);
		}

		foreach ($this->images as $filename => $img) {

			foreach ($frgb as $index => $f) {
				//get the current replace color in find with the index or the last color in the array
				$r = (isset($rrgb[$index])) ? $rrgb[$index] : $rrgb[(count($rrgb) - 1)];

				$index = imagecolorclosest($img, $f['r'], $f['g'], $f['b']);
				//find
				imagecolorset($img, $index, $r['r'], $r['g'], $r['b']);
				//replace
			}

			$this -> saveImage((($fileNamePrefix != '') ? $fileNamePrefix . '_' : '') . $filename, $img);

			imagedestroy($img);
		}
	}

	/**
	 * colorizer::hexToRGB()
	 *
	 * turn #333 to rgb code
	 *
	 * @param mixed $hex
	 * @return array
	 */
	private function hexToRGB($hex) {
		$hex = str_replace("#", "", $hex);
		$color = array();

		if (strlen($hex) == 3) {
			$color['r'] = hexdec(substr($hex, 0, 1));
			$color['g'] = hexdec(substr($hex, 1, 1));
			$color['b'] = hexdec(substr($hex, 2, 1));
		} else if (strlen($hex) == 6) {
			$color['r'] = hexdec(substr($hex, 0, 2));
			$color['g'] = hexdec(substr($hex, 2, 2));
			$color['b'] = hexdec(substr($hex, 4, 2));
		}

		return $color;
	}

	/**
	 * colorizer::getExtention()
	 *
	 * @param mixed $file
	 * @return string
	 */
	private function getExtention($file) {
		$parts = pathinfo($file);
		return strtolower($parts['extension']);
	}

	/**
	 * colorizer::createImage()
	 *
	 * @param mixed $filename
	 * @return iamge object
	 */
	private function createImage($filename) {
		$ret = '';
		switch($this->getExtention($filename)) {
			case 'png' :
				$ret = imagecreatefrompng($filename);
				break;
			case 'jpg' :
			case 'jpeg' :
				$ret = imagecreatefromjpeg($filename);
				break;
			case 'bmp' :
				$ret = imagecreatefrombmp($filename);
				break;
			case 'gif' :
				$ret = imagecreatefromgif($filename);
				break;
			default :
				throw new Exception('unknown file extension');
				break;
		}
		return $ret;

	}

	private function saveImage($filename, $img) {

		switch($this->getExtention($filename)) {
			case 'png' :
			//save the alpha - prevent transparent px from turning black
				imagealphablending($img, false);
				imagesavealpha($img, true);

				imagepng($img, self::CACHE_PATH . $filename);
				break;
			case 'jpg' :
			case 'jpeg' :
				imagejpeg($img, self::CACHE_PATH . $filename);
				break;
			case 'bmp' :
				imgbmp($img, v::CACHE_PATH . $filename);
				break;
			case 'gif' :
				imagegif($img, self::CACHE_PATH . $filename);
				break;
			default :
				throw new Exception('unknown file extension');
				break;
		}
	}

}
?>