The provided example is wrong. Here's a correct sample:$matrix = [[1,-1,1],[-1,1,-1],[1,-1,1]];$kernel = \ImagickKernel::fromMatrix($matrix); $imagick = new Imagick();$imagick->readimage($file.'/z.png');$imagick->convolveImage ($kernel);$imagick->writeimage('convolve.png');$imagick->clear();$imagick->destroy();