Imagick::setImageType

The different image types that can be specified are (from the Imagick::getImageType doc page):    Imagick::IMGTYPE_UNDEFINED    Imagick::IMGTYPE_BILEVEL    Imagick::IMGTYPE_GRAYSCALE    Imagick::IMGTYPE_GRAYSCALEMATTE    Imagick::IMGTYPE_PALETTE    Imagick::IMGTYPE_PALETTEMATTE    Imagick::IMGTYPE_TRUECOLOR    Imagick::IMGTYPE_TRUECOLORMATTE    Imagick::IMGTYPE_COLORSEPARATION    Imagick::IMGTYPE_COLORSEPARATIONMATTE    Imagick::IMGTYPE_OPTIMIZEThe MATTE variants are equivalent to GrayscaleAlpha, etc. in the ImageMagick command line. If you're making something grayscale, I would recommend using IMGTYPE_GRAYSCALEMATTE.<?php$im->setImageType(Imagick::IMGTYPE_GRAYSCALEMATTE);?>

The cleaner way to set the type to grayscale is to use the Imagick class constant.$oBw = new \Imagick($sSourceImage);$oBw->setImageType(\Imagick::IMGTYPE_GRAYSCALE);I've found this to be a rather harsh 'convert to grayscale' approach. Fred's color2gray script works much better, but it's written in Bash. Time to get it ported over lolhttp://www.fmwconcepts.com/imagemagick/color2gray/index.php

This function can be used to desaturate an image, i.e. to convert a coloured image into a greyscale:<?php$im = new Imagick ("image.jpg");$im->setImageType (2);//is now in 256 shades of grey?>