Cropping images in PHP leaves black space - php

Question

This is likely a duplicate, but every solution I have looked at seems to not work for me, so not sure what I am doing differently.
I don't understand too much about image manipulation yet, but cropping images seems to add lots of black space around the right/bottom of the image when using imagecopyresampled to place it over another. They are all JPEGs.
This is my crop function:
function thumbImage($thumb_img,$img_size,$shape){
$width = 250;
$height = 250;
list($w, $h) = $img_size;
if($w > $h) {
$new_height = $height;
$new_width = floor($w * ($new_height / $h));
$crop_x = ceil(($w - $h) / 2);
$crop_y = 0;
} else {
$new_width = $width;
$new_height = floor( $h * ( $new_width / $w ));
$crop_x = 0;
$crop_y = ceil(($h - $w) / 2);
}
$tmp_img = imagecreatetruecolor($width,$height);
imagecopyresampled($tmp_img, $thumb_img, 0, 0, $crop_x, $crop_y, $new_width, $new_height, $w, $h);
return $tmp_img;
}
Any solutions with an explanation of how it works would be greatly appreciated.

Answer 1

Try this:
function thumbImage($source_img,$max_size){
list($w, $h) = getimagesize($source_img);
if($w>$h){
$width = ($max_size/$h)*$w;
$height = $max_size;
}else{
$width = $max_size;
$height = ($max_size/$w)*$h;
}
$x = ($max_size-$width)/2;
$y = ($max_size-$height)/2;
$thumb_img = imagecreatetruecolor($max_size,$max_size);
imagecopyresampled($thumb_img, $source_img, $x, $y, 0, 0, $width, $height, $w, $h);
return $thumb_img;
}