I try to use PHP GD library to resize image to thumbnail size, however I found the small converted image has bad quality(distorted color), how can I improve the image quality by using PHP GD library:
$first=imagecreatefromjpeg($uploadfile);
define(MAX_WIDTH, 180);
define(MAX_HEIGHT, 135);
$width = imagesx($first);
$height = imagesy($first);
$scale = min(MAX_WIDTH/$width, MAX_HEIGHT/$height);
$new_width = floor($scale*$width);
$new_height = floor($scale*$height);
$second=imagecreate($new_width, $new_height);
imagecopyresized($second,$first,0,0,0,0,$new_width,$new_height,$width,$height);
imagejpeg($second,$v_thumbnailfile);
Thanks for any response.