Resize/crop/pad a picture to a fixed size

Question

I need to resize a picture to a fixed size. But it has to keep the factors between the width and height.

Say I want to resize a picture from 238 (w) X 182 (

Answer 1

This doesn't crop the picture, but leaves space around the new image if necessary, which I think is a better approach (than cropping) when creating thumbnails.

$w = 210;
$h = 150;

$orig_w = imagesx($original);
$orig_h = imagesy($original);

$w_ratio = $orig_w / $w;
$h_ratio = $orig_h / $h;

$ratio = $w_ratio > $h_ratio ? $w_ratio : $h_ratio;

$dst_w = $orig_w / $ratio;
$dst_h = $orig_h / $ratio;
$dst_x = ($w - $dst_w) / 2;
$dst_y = ($h - $dst_h) / 2;

$thumbnail = imagecreatetruecolor($w, $h);

imagecopyresampled($thumbnail, $original, $dst_x, $dst_y,
                   0, 0, $dst_w, $dst_h, $orig_w, $orig_h);