/**
    * Proprtionally crop and resize an image file
    *
    * @param string $format expect jpg, jpeg, gif, or png
    * @param string $filein path to read image file
    * @param string $fileout path to write converted image file
    * @param int $imagethumbsize_w width for conversion
    * @param int $imagethumbsize_h height for conversion
    * @param int $red RGB red value for imagecolorallocate()
    * @param int $green RGB green for imagecolorallocate()
    * @param int $blue RGB blue for imagecolorallocate()
    */
    static function resize($format, $filein, $fileout, $imagethumbsize_w, $imagethumbsize_h, $red = 255, $green = 255, $blue = 255) {

        $format = strtolower($format);
        if ($format == 'jpg') $format = 'jpeg'; // fix stupid mistake
        if (!($format == 'jpeg' || $format == 'gif' || $format == 'png'))  {
            throw new Exception('Invalid image format');
        }

        $func = 'imagecreatefrom' . $format;
        $image = $func($filein);

        $width = $imagethumbsize_w;
        $height = $imagethumbsize_h;
        list($width_orig, $height_orig) = getimagesize($filein);

        if ($width_orig < $height_orig) {
            $height = ($imagethumbsize_w / $width_orig) * $height_orig;
        }
        else {
            $width = ($imagethumbsize_h / $height_orig) * $width_orig;
        }

        //if the width is smaller than supplied thumbnail size
        if ($width < $imagethumbsize_w) {
            $width = $imagethumbsize_w;
            $height = ($imagethumbsize_w/ $width_orig) * $height_orig;
        }

        //if the height is smaller than supplied thumbnail size
        if ($height < $imagethumbsize_h) {
            $height = $imagethumbsize_h;
            $width = ($imagethumbsize_h / $height_orig) * $width_orig;
        }

        $thumb = imagecreatetruecolor($width , $height);
        $bgcolor = imagecolorallocate($thumb, $red, $green, $blue);
        ImageFilledRectangle($thumb, 0, 0, $width, $height, $bgcolor);
        imagealphablending($thumb, true);

        imagecopyresampled($thumb, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
        $thumb2 = imagecreatetruecolor($imagethumbsize_w , $imagethumbsize_h);
        // true color for best quality
        $white = imagecolorallocate($thumb2, 255, 255, 255);
        ImageFilledRectangle($thumb2, 0, 0, $imagethumbsize_w , $imagethumbsize_h , $white);
        imagealphablending($thumb2, true);

        $w1 =($width/2) - ($imagethumbsize_w/2);
        $h1 = ($height/2) - ($imagethumbsize_h/2);

        imagecopyresampled($thumb2, $thumb, 0, 0, $w1, $h1, $imagethumbsize_w , $imagethumbsize_h ,$imagethumbsize_w, $imagethumbsize_h);

        $func = 'image' . $format;
        $func($thumb2, $fileout);

    }