image.php

<?php  
class ImageHelper extends Helper { 

    var $helpers = array('Html'); 
     
    var $cacheDir = 'cache'; // relative to IMAGES_URL path 
 
    function resize($path, $dst_w, $dst_h, $htmlAttributes = array(), $return = false) { 
         
        $types = array(1 => "gif", "jpeg", "png", "swf", "psd", "wbmp"); // used to determine image type 
         
        $fullpath = ROOT.DS.APP_DIR.DS.WEBROOT_DIR.DS.IMAGES_URL; 
     
        $url = $fullpath.$path; 
        
        list($w, $h, $type) = getimagesize($url);
        $r = $w / $h;
        $dst_r = $dst_w / $dst_h;
        
        if ($r > $dst_r) {
            $src_w = $h * $dst_r;
            $src_h = $h;
            $src_x = ($w - $src_w) / 2;
            $src_y = 0;
        } else {
            $src_w = $w;
            $src_h = $w / $dst_r;
            $src_x = 0;
            $src_y = ($h - $src_h) / 2;
        }

        $relfile = $this->cacheDir.'/'.$dst_w.'x'.$dst_h.'_'.basename($path); // relative file 
        $cachefile = $fullpath.$relfile;
         
        if (file_exists($cachefile)) {
            if (@filemtime($cachefile) >= @filemtime($url)) {
                $cached = true;
            } else {
                $cached = false;
            }
        } else { 
            $cached = false; 
        } 
         
        if (!$cached) { 
            $image = call_user_func('imagecreatefrom'.$types[$type], $url); 
            if (function_exists("imagecreatetruecolor")) {
                $temp = imagecreatetruecolor($dst_w, $dst_h); 
                imagecopyresampled($temp, $image, 0, 0, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h); 
            } else { 
                $temp = imagecreate ($dst_w, $dst_h); 
                imagecopyresized($temp, $image, 0, 0, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h); 
            } 
            call_user_func("image".$types[$type], $temp, $cachefile); 
            imagedestroy($image); 
            imagedestroy($temp); 
        }

        return $this->Html->image($relfile);
    }
}
?>

Keep it up :)