A helper to convert images inside cms to the right width and height

gistfile1.php

<?php

/**
 * A simple helper that converts img tags to it's thumbnails so we don't load to big images. It also does it the way around.
 *
 * TODO Check if we can reduce number of regexes used.
 * @author Ward Peeters <ward@coding-tech.com>
 */
class ContentOptimiser
{
	public static function optimise($data)
	{
		// Check if we have images
		if (preg_match_all('/<img([^>]+)>/', $data, $matches) > 0) {
			$iconFiles = ThumbnailCreator::getIcons();

			foreach ($matches[1] as $match) {
				// just check if we have a width or height
				if (preg_match('/src="([^"]+)".*(height:\s?\d+px;|width:\s?\d+px;|height="\d+"|width="\d+")/', $match, $source)) {
					$info = pathinfo($source[1]);
					list($width, $height) = self::getSize($match);

					// only do this when we have width or height
					if (($width || $height) && !in_array($info['filename'], $iconFiles)) {
						list($origWidth, $origHeight) = @getimagesize(BASEPATH . preg_replace('|' . BASEURL . '|', '', $source[1], 1));

						// and not the same as default size
						if (($width && $origWidth != $width) || ($height && $origHeight != $height)) {
							$newSrc = $info['dirname'] . '/' . sprintf('%s-%dx%d.%s', $info['filename'], $width, $height, $info['extension']);

							$data = preg_replace('|src="' . $source[1] . '"|', 'src="' . $newSrc . '"', $data, 1);
						}
					}
				}
			}
		}

		return $data;
	}

	public static function revert($data)
	{
		if (preg_match_all('/<img.*src=".*-(\d+)x(\d+)([^>]+)">/', $data, $matches) > 0) {
			foreach ($matches[0] as $key => $match) {
				// split all attributes out
				preg_match_all('/(\w+)\s*=\s*("[^"]*"|\'[^\']*\'|[^"\'\s>]*)/', $match, $attributes);

				$attrString = '';
				$hasStyles = $widthOrHeight = false;
				// just check attributes for width and height
				foreach ($attributes[1] as $k => $attr) {
					if (isset($attributes[2][$k])) {
						if ($attr == 'src' && ($matches[1][$key] || $matches[2][$key])) {
							$attributes[2][$k] = str_replace('-' . $matches[1][$key] . 'x' . $matches[2][$key], '', $attributes[2][$k]);
						} else if ($attr == 'width' && $matches[1][$key]) {
							$attributes[2][$k] = $matches[1][$key];
							$widthOrHeight = true;
						} else if ($attr == 'height' && $matches[1][$key]) {
							$attributes[2][$k] = $matches[2][$key];
							$widthOrHeight = true;
						} else if ($attr == 'style') {
							$hasStyles = true;

							if (preg_match_all('/(width:\s?(\d+)px;|height:\s?(\d+)px;)/', $attributes[2][$k], $style)) {
								$widthOrHeight = true;
								// replace width and height in style
								foreach ($style[0] as $l => $v) {
									if (strpos($v, 'height') !== false && $matches[2][$key]) {
										$attributes[2][$k] = str_replace($v, 'height: ' . $matches[2][$key] . 'px;', $attributes[2][$k]);
									} else if (strpos($v, 'width') !== false && $matches[1][$key]) {
										$attributes[2][$k] = str_replace($v, 'width: ' . $matches[1][$key] . 'px;', $attributes[2][$k]);
									}
								}
							} else { // couldn't find height or width
								if ($matches[1][$key]) {
									$attributes[2][$k] .= 'width: ' . $matches[2][$key] . 'px;';
								}
								if ($matches[2][$key]) {
									$attributes[2][$k] .= 'height: ' . $matches[2][$key] . 'px;';
								}
							}
						}

						$attrString .= ' ' . $attr . '="' . trim($attributes[2][$k], '"') . '"';
					}
				}

				// if no width or height is found in the element than we should add it ourselves
				if (!$widthOrHeight && !$hasStyles) {
					$styleString = '';

					if ($matches[1][$key]) {
						$styleString .= 'width: ' . $matches[2][$key] . 'px;';
					}
					if ($matches[2][$key]) {
						$styleString .= 'height: ' . $matches[2][$key] . 'px;';
					}

					if ($styleString) {
						$attrString .= ' style="' . $styleString . '"';
					}
				}

				$newImage = '<img' . $attrString . ' />';

				$data = str_replace($match, $newImage, $data);
			}
		}

		return $data;
	}

	protected static function getSize($line)
	{
		preg_match('/width="(\d+)"|width:\s?(\d+)px;?/', $line, $widths);
		preg_match('/height="(\d+)"|height:\s?(\d+)px;?/', $line, $heights);

		return array(
			(int) $widths ? (count($widths) > 2 ? $widths[2] : $widths[1]) : 0,
			(int) $heights ? (count($heights) > 2 ? $heights[2] : $heights[1]) : 0,
		);
	}
}