Images resizing (to make bigger)

Hello,
I have a function to decrease Image in pixels importing
But it doesn`t work to INCREASE image.
WHY? May be You can explain me is it possible at all to make images BIGGER importing XML with Wp all import?

Thanks.

Sergey

/*from GTHUB:
https://github.com/tomasbal/wp-all-import-resize-images-on-upload/blob/master/resize.php*/


//Images resize on upload handling
add_action('pmxi_gallery_image', 'my_gallery_image', 10, 3);

function my_gallery_image($pid, $attid, $image_filepath) {
$attachment = get_post($attid);
$square=500;

// Load up the original image
//get extension
$ext = pathinfo($image_filepath, PATHINFO_EXTENSION);
if($ext == 'png'){
$src = imagecreatefrompng($image_filepath);
}
else{
$src = imagecreatefromjpeg($image_filepath);
}

$w = imagesx($src); // image width
$h = imagesy($src); // image height

// Create output canvas and fill with white
$final = imagecreatetruecolor($square,$square);
$bg_color = imagecolorallocate ($final, 255, 255, 255);
imagefill($final, 0, 0, $bg_color);

// Check if portrait or landscape
if($h>=$w){
// Portrait, i.e. tall image
$newh=$square;
$neww=intval($square$w/$h); // Resize and composite original image onto output canvas imagecopyresampled( $final, $src, intval(($square-$neww)/2),0, 0,0, $neww, $newh, $w, $h); } else { // Landscape, i.e. wide image $neww=$square; $newh=intval($square$h/$w);
imagecopyresampled(
$final, $src,
0,intval(($square-$newh)/2),
0,0,
$neww, $newh,
$w, $h);
}

// Write result
//get extension
if($ext == 'png'){
imagepng($final,$image_filepath);
}
else{
imagejpeg($final,$image_filepath);
}
// do something with $attachment image
exec('wpcli --allow-root media regenerate '.$attid );
}

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