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 public static function getPrev($img,$sfx='-prewXS',$width=150, $height=150,$quility=5,$refresh=false) {

        jimport( 'joomla.filesystem.file' );
        jimport('joomla.image.image');

        $prevPath=JFile::stripExt($img).$sfx.'.jpg';



        if(JFile::exists( JPATH_ROOT.'/'.$prevPath) && !$refresh) {
            return $prevPath;
        }



        $prev = new JImage();
        $prev->loadFile(JPATH_ROOT.$img);

        $resize=$prev->resize($width, $height, true, JImage::SCALE_INSIDE );
        $resize->toFile(JPATH_ROOT.$prevPath, IMAGETYPE_JPEG, array('quality'=>$quility));


        return $prevPath;
    }