WordPress – Get thumbnails for your images with custom sizes

If you want to display thumbnails along with the post excerpts then you can use the WordPress built in image crop function rather than going for something like phpThumb which is something good, but your server resources should support.

function get_the_thumb($width, $height, $cut = true){
	if(is_null($height)) $height = $width;

    // read the content
    $content = apply_filters('the_content', get_the_content());
    // extracct the first image
    $img = extract_image($content);
	if(strlen($img)) {
		if(strpos($img, 'kish.in')===false) {
	     	return "http://img.xxxx.ixxxxn/index.php?url={$img}&w={$width}&h={$height}";
		}
		else {
			return generate_thumb($img, $width, $height, $cut);
		}
	}
	else {
		return "";
	}
    // return the thumb

}

function generate_thumb($img_url, $width, $height, $cut = true){
    // cut the url
    require_once(ABSPATH . '/wp-admin/includes/image.php');
    if(strpos($img_url, 'wp-content')===false) {
    	$img = str_replace("http://images.kish.in", "", $img_url );
    	$img='images'.$img;
    	$prefix="http://images.kish.in";
    }
    else {
    	$img = substr($img_url, strpos($img_url, 'wp-content'));
    	$prefix=get_bloginfo('wpurl');
    }
    // resize the image
  	$thumb = image_resize($img,$width,$height,$cut);
  	if(is_string($thumb)) {
	  	if($prefix=="http://images.kish.in") {
	  		$thumb=str_replace("images/", "", $thumb);
	  	}
	  	//echo $thumb;
	    return $prefix . '/' .  $thumb;
  	}
  	else {
  		return "";
  	}
}

/*
 * Extract the first image src inside some html content
 *
 * @param html $content
 */
function extract_image($content){
    $pattern = '~<img />~';
    preg_match($pattern, $content, $match);
    return $match[1];
}

One problem is that you can only use images that are stored on your server. I use a sub domain to store all the images, so I am checking for that. External images are taken care by a different script which uses phpThumb.

Tagged as: Generate Thumbs Automatically, Thumbnail Images automatic generation, Wordpress get custom size image, Wordpress get first image, Wordpress get image by custom size name, Wordpress get thumbnail, Wordpress thumbnails