Improve imagick performance when resizing animated gifs

Question

I am resizing an animated gif and adding a background to it using the imagick extension in PHP.

This is the code I am using:

$image = new Imagick('myfile.gif');
$image = $image->coalesceimages();

$final = new \Imagick();

foreach ($image as $frame){

    $frame->thumbnailImage($width, $height, true);
    $geometry = $image->getImageGeometry();

    $x = ( $width - $geometry['width'] ) / 2;
    $y = ( $height - $geometry['height'] ) / 2;

    $canvas = new \Imagick();
    $canvas->newImage( $width, $height, $background);

    $canvas->compositeImage( $image, \Imagick::COMPOSITE_OVER, $x, $y );

    $final->addimage($canvas);
}

$final->desconstructimages();
$final->writeImages('resized.gif', true);

The code works and the resized images are perfect. However, when resizing animated gifs, it takes quite a while.

With the above code, it takes about 10 seconds to resize a 36kb gif with 60 frames. With non-animated images, it takes about half a second.

I am running ImageMagick 6.8.1-0 2012-12-20 on Ubuntu 12.10 32-bit.

Is there anyway to speed up the resizing?

Update:

I found out that thumbnailImage does not need to be called on every frame, so this is now what I am using:

$image = new Imagick('myfile.gif');
$image = $image->coalesceimages();

$final = new \Imagick();

$image->thumbnailImage($width, $height, true);
$geometry = $image->getImageGeometry();

$x = ( $width - $geometry['width'] ) / 2;
$y = ( $height - $geometry['height'] ) / 2;

foreach ($image as $frame){

    $canvas = new \Imagick();
    $canvas->newImage( $width, $height, $background);

    $canvas->compositeImage( $image, \Imagick::COMPOSITE_OVER, $x, $y );

    $final->addimage($canvas);
}

$final->desconstructimages();
$final->writeImages('resized.gif', true);

By only doing the thumbnailing once, I am now saving on average, 1 second (10%!) compared to before! So, to the guy who said, I should be happy with the performance and not complain, this is proof that you should investigate and improve things that you were previously happy with, otherwise you will always be a mediocre developer.

I am of course, trying to decrease the conversion time further, and will be doing some profiling to determine which calls are the most expensive and then target those.

Answer 1

After spending a while trying to optimize things, I ended up with an average time of around 6.5 seconds, which is much better than the initial 10 seconds.

I am now resizing the animation outside the loop and using optimizeImageLayers which is faster than deconstructImages and also keeps the filesize down.

$image = new Imagick('myfile.gif');
$image = $image->coalesceimages();

$final = new \Imagick();

foreach ($image as $frame){

    $image->thumbnailImage($width, $height, true);
    $geometry = $image->getImageGeometry();

    $x = ( $width - $geometry['width'] ) / 2;
    $y = ( $height - $geometry['height'] ) / 2;

    $canvas = new \Imagick();
    $canvas->newImage( $width, $height, $background);

    $canvas->compositeImage( $image, \Imagick::COMPOSITE_OVER, $x, $y );

    $final->addimage($canvas);
}

$final = $final->optimizedImageLayers();
$final->writeImages('resized.gif', true);

This is currently what I am using and am quite happy with it. However, I am will be looking at tweaking imagemagick's settings and playing with the color depth, etc to make it better, once I find some spare time of course :)

Answer 2

I know this might be a little late but for those like me who end up here searching for a way to resize a .gif here is a little code that I wrote that also keeps a max of 25 frames in the image (this code keeps the original animation speed).

$original = new \Imagick('/path/to/original/image');
$new = new \Imagick();

$i = 0; 
$frameStep = ceil($original->getNumberImages() / 25);
foreach ($original as $frame) {
    if ($i % $frameStep === 0) {
        $delay = $frame->getImageDelay();

        $frame->thumbnailImage($x, $y);
        $frame->setImagePage($x, $y, 0, 0);
        $frame->setImageDelay($delay * $frameStep);

        $new->addImage($frame->getImage());
    }

    $i++;
}

file_put_contents('/path/to/NEW/file', $new->getImagesBlob());

$new->clear();
$new->destroy();
$original->clear();
$original->destroy();

Answer 3

If 60 frames take 10 seconds to resize, then each frame actually takes 1/6th of a second, which is even better, the your result for 1 frame, isn't it? You should not complain, when 60 time more work takes a bit longer.