img_resize

function img_resize($src, $dest, $width, $height, $rgb=0xFFFFFF, $quality=100) {
    if (!file_exists($src)) return false;

    $size = getimagesize($src);

    if ($size === false) return false;

    $format = strtolower(substr($size['mime'], strpos($size['mime'],'/')+1));

    $icfunc = "imagecreatefrom" . $format;
    if (!function_exists($icfunc)) return false;

    $x_ratio = $width / $size[0];
    $y_ratio = $height / $size[1];

    $ratio       = min($x_ratio, $y_ratio);
    $use_x_ratio = ($x_ratio == $ratio);

    $new_width   = $use_x_ratio  ? $width  : floor($size[0] * $ratio);
    $new_height  = !$use_x_ratio ? $height : floor($size[1] * $ratio);

    $new_left    = $use_x_ratio  ? 0 : floor(($width - $new_width) / 2);
    $new_top     = !$use_x_ratio ? 0 : floor(($height - $new_height) / 2);

    $isrc = $icfunc($src);
    $idest = imagecreatetruecolor($width, $height);

    imagefill($idest, 0, 0, $rgb);
    imagecopyresampled($idest, $isrc, $new_left, $new_top, 0, 0, $new_width, $new_height, $size[0], $size[1]);

    imagejpeg($idest, $dest, $quality);

    imagedestroy($isrc);
    imagedestroy($idest);

    return true;
}