Create product thumbnail image from admin side in oscommerce

  function resize_small($source_image, $destination, $tn_w, $tn_h, $quality = 100, $wmsource = false)
{
    $info = getimagesize($source_image);
	//echo $source_image;die;
 
    $imgtype = image_type_to_mime_type($info[2]);
 
    #assuming the mime type is correct
    switch ($imgtype) {
        case 'image/jpeg':
            $source = imagecreatefromjpeg($source_image);
			//print_r ($source);die;
            break;
        case 'image/gif':
            $source = imagecreatefromgif($source_image);
            break;
        case 'image/png':
            $source = imagecreatefrompng($source_image);
            break;
        default:
            die('Invalid image type.');
    }
 
    #Figure out the dimensions of the image and the dimensions of the desired thumbnail
    $src_w = imagesx($source);
    $src_h = imagesy($source);
 
 
    #Do some math to figure out which way we'll need to crop the image
    #to get it proportional to the new size, then crop or adjust as needed

    $x_ratio = $tn_w / $src_w;
    $y_ratio = $tn_h / $src_h;
 
    if (($src_w <= $tn_w) && ($src_h <= $tn_h)) {
        $new_w = $src_w;
        $new_h = $src_h;
    } elseif (($x_ratio * $src_h) < $tn_h) {
        $new_h = ceil($x_ratio * $src_h);
        $new_w = $tn_w;
    } else {
        $new_w = ceil($y_ratio * $src_w);
        $new_h = $tn_h;
    }
 
 
 
    $newpic = imagecreatetruecolor(round($new_w), round($new_h));
    imagecopyresampled($newpic, $source, 0, 0, 0, 0, $new_w, $new_h, $src_w, $src_h);
    $final = imagecreatetruecolor($tn_w, $tn_h);
    $backgroundColor = imagecolorallocate($final, 255, 255, 255);
    imagefill($final, 0, 0, $backgroundColor);
    //imagecopyresampled($final, $newpic, 0, 0, ($x_mid - ($tn_w / 2)), ($y_mid - ($tn_h / 2)), $tn_w, $tn_h, $tn_w, $tn_h);
    imagecopy($final, $newpic, (($tn_w - $new_w)/ 2), (($tn_h - $new_h) / 2), 0, 0, $new_w, $new_h);
 
    #if we need to add a watermark
    if ($wmsource) {
        #find out what type of image the watermark is
        $info    = getimagesize($wmsource);
        $imgtype = image_type_to_mime_type($info[2]);
 
        #assuming the mime type is correct
        switch ($imgtype) {
            case 'image/jpeg':
                $watermark = imagecreatefromjpeg($wmsource);
                break;
            case 'image/gif':
                $watermark = imagecreatefromgif($wmsource);
                break;
            case 'image/png':
                $watermark = imagecreatefrompng($wmsource);
                break;
            default:
                die('Invalid watermark type.');
        }
 
        #if we're adding a watermark, figure out the size of the watermark
        #and then place the watermark image on the bottom right of the image
        $wm_w = imagesx($watermark);
        $wm_h = imagesy($watermark);
        imagecopy($final, $watermark, $tn_w - $wm_w, $tn_h - $wm_h, 0, 0, $tn_w, $tn_h);
 
    }
	  $infoo = pathinfo($destination);
		$image_name =  basename($destination,'.'.$infoo['extension']);
		$ext = end(explode('.',  $destination));
		$destination = DIR_FS_CATALOG_IMAGES.$image_name.'_small.'.$ext;
    if (imagejpeg($final, $destination, $quality)) {
				//echo $destination;die;
 
        return true;
    }
    return false;
}

$sql_data_array['products_image'] = tep_db_prepare_input($products_image->filename);

$products_image_name = $products_image->filename ;
resize_small(DIR_FS_CATALOG_IMAGES .$products_image_name, DIR_FS_CATALOG_IMAGES.$products_image_name, 100, 120);