Imagick::setImageType()

(PECL imagick 2.0.0)

Sets the image type

说明

Imagick::setImageType(int $image_type): bool

Sets the image type.

参数

$image_type

返回值

成功时返回TRUE。

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
?>

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 lol
http://www.fmwconcepts.com/imagemagick/color2gray/index.php