(PECL imagick 2, PECL imagick 3)
Imagick::setImageType — Sets the image type
image_type
成功时返回 true。
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.phpThe 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_OPTIMIZE
The 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);
?>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
?>