(PECL imagick 2.0.0)
Imagick::uniqueImageColors — Discards all but one of any pixel color
Discards all but one of any pixel color. This method is available if Imagick has been compiled against ImageMagick version 6.2.9 or newer.
Returns TRUE on success.
Example #1 Imagick::uniqueImageColors()
<?php
function uniqueImageColors($imagePath) {
$imagick = new \Imagick(realpath($imagePath));
//Reduce the image to 256 colours nicely.
$imagick->quantizeImage(256, \Imagick::COLORSPACE_YIQ, 0, false, false);
$imagick->uniqueImageColors();
$imagick->scaleimage($imagick->getImageWidth(), $imagick->getImageHeight() * 20);
header("Content-Type: image/png");
echo $imagick->getImageBlob();
}
?>