Imagick::paintTransparentImage

Actually it does seem to work just not the way expected perhaps.Looking at the fuzz option on ImageMagick's site (http://www.imagemagick.org/script/command-line-options.php#fuzz), "The distance can be in absolute intensity units or, by appending % as a percentage of the maximum possible intensity (255, 65535, or 4294967295)."As it requires a float, the percentage value won't work so it actually one of the max intensity values.  In my case, the images I was working with seemed to have max intensity values of 65535.  So a fuzz of 6500, for roughly 10%, seemed to do the trick.The part that might be problematic though is how do you determine the max intensity of a color/image?  Using a static 6500 would be fine until I would have to convert an image with a max intensity other than 65535.  If it's 255 it would wipe the entire image.  Or fall far short on the fuzz with the larger value.

Have a look at this thread on Stackoverflow for the answer regarding how to determine the max intensity of an image.http://stackoverflow.com/questions/26239130/determine-max-possible-intensity-of-image/26240656#26240656In short here is the code to make the $fuzz parameter behave more like you would expect (it now represents a percentage between 0-100). The $fuzz value should now be a float between 0 and 1.class SaneImagick extends Imagick{    public function paintTransparentImage($target, $alpha, $fuzz)    {        $iQuantumDepth = pow(2, $this->getQuantumDepth()['quantumDepthLong']);        return parent::paintTransparentImage($target, $alpha, $fuzz * $iQuantumDepth);    }}

The fuzz is just working well in a range of 0 to 65535.I suggest you to try to move fuzz on a color spectrum image.1/ Get a color spectrum ( Google Image has a lot )2/ Try this code :<?php    function fuzzTest($source, $target, $fuzz) {        // Loads image        $im = new Imagick($source);        // Resizes images to make them easily comparable        $im->resizeImage(320, 240, Imagick::FILTER_LANCZOS, 1, true);                // Apply fuzz        $im->paintTransparentImage($im->getImagePixelColor(0, 0), 0, $fuzz);                 // Writes image        $im->setImageFormat('png');        $im->writeImage($target);        $im->destroy();                 return true;     }     for ($i = 0; ($i <= 10); $i++) {         fuzzTest('spectrum.png', "test_{$i}.png", (6553.5 * $i));         echo '<img src="test_' . $i . '.png" />&nbsp;';     }  ?>