使用Imagick更改GIF动画的质量/压缩效果

Question

I would like to apply a compression on animated gif

I tried this :

//Resize
$image_resize = new Imagick();
$image_resize->readImage($image->getPathName());

$dimension = $image_resize->getImageGeometry();
$width = $dimension['width'];
$height = $dimension['height'];

$new_width = 250;
$new_height = ($new_width*$height) / $width;

$compression = 50;

$image_resize->setCompression($compression);
$image_resize->setCompressionQuality($compression);

$image_resize = $image_resize->coalesceImages();

foreach ($image_resize as $frame) {
    $frame->thumbnailImage($new_width, $new_height);
    $frame->setImageCompression($compression);
    $frame->setImageCompressionQuality($compression);
}

$image_resize = $image_resize->deconstructImages();

The size change but not the compression/quality