PHP Imagick Resizing Gif frames has weird issues - php

Question

I am trying to resize all frames of a gif and sometimes they turn out extremely weird.
I've seen examples using the command line and I would like to try and avoid this for now.
Original:
Resized:
You can see clearly the problem.
Now my code:
$imgBlob = file_get_contents(__DIR__ . '/../assets/test_gif.gif');
if ($imgBlob === false) {
echo 'img blob failed!' . PHP_EOL;
return;
}
$img = new Imagick();
$img->readImageBlob($imgBlob);
$img->coalesceImages();
$count = 0;
foreach ($img as $_img) {
// $_img->coalesceImages();
$imgWidth = $_img->getImageWidth();
$imgHeight = $_img->getImageHeight();
$ratio = $imgHeight / $imgWidth;
$resizeWidth = 200;
$resizeHeight = 300;
if ($ratio > 0) {
$resizeWidth = round($resizeHeight / $ratio, 0);
} else {
$resizeHeight = round($resizeWidth / $ratio, 0);
}
//if ($_img->adaptiveResizeImage($resizeWidth, $resizeHeight) === false) {
if ($_img->resizeImage($resizeWidth, $resizeHeight, Imagick::FILTER_CATROM, 1, 0) === false) {
echo 'FAILED' . PHP_EOL;
}
$count++;
}
$thumbnailOnDisk = __DIR__ . '/../assets/test_resized.gif';
if (file_exists($thumbnailOnDisk)) {
unlink($thumbnailOnDisk);
}
$img = $img->deconstructImages();
if ($count > 1) {
$file = $img->writeImages($thumbnailOnDisk, true);
} else {
$file = $img->writeImage($thumbnailOnDisk);
}
echo 'DONE' . PHP_EOL;
Not sure exactly what coalesceImages or deconstructImages is doing and I am having a hard time finding an example online that would fix my problem.

Answer 1

$img->coalesceImages();
Returns an imagick object, which I was discarding.
$img = $img->coalesceImages();
Works.

Answer 2

As you resize the image, you need to set size of image page as well.
http://php.net/manual/en/imagick.setimagepage.php
I have read once that the header of the gif might not say the correct image size in some cases. This is why it is useful to set the image page any way.
Example:
`$image->resizeImage(120, 110, imagick::FILTER_CATROM, 1);
// Set the page size
$image->setImagePage(120, 110, 0, 0);