repeat watermark image with imagick in php

repeat_watermark_imagick.php

// load images
$image = new Imagick("main_image.jpg");
$watermark = new Imagick("stamp.png");

// main image dimension
$geo=$image->getImageGeometry();
$x=$geo['width'];
$y=$geo['height'];

// stamp image dimension
$geo_stamp=$watermark->getImageGeometry();
$sx=$geo_stamp['width'];
$sy=$geo_stamp['height'];

// repeat stamp image and write it on main image
for($i=0;$i<=round($x/$sx)+1;$i++){
    for($j=0;$j<=round($y/$sy)+1;$j++){
        // compose watermark onto image
        $image->compositeImage( $watermark, $watermark->getImageCompose(), ($i*$sx), ($j*$sy));
    }
}

// export final image
$image->writeImage("main_image_watermark.jpg");