(PECL imagick 2, PECL imagick 3)
Imagick::setImageType — Sets the image type
Converts the image to the given type, which combines a color model with the presence or absence of an alpha channel. Depending on the type, this may change the colorspace, quantize the colors, or change whether the image has an alpha channel.
Imagick::setImageType() modifies the image itself. To set the type that subsequent images are written with instead, use Imagick::setType().
image_type
One of the
imagick::IMGTYPE_*
constants. imagick::IMGTYPE_UNDEFINED and
imagick::IMGTYPE_OPTIMIZE convert nothing, but are
still recorded on the image.
Liefert true bei Erfolg.
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
?>