Imagick::setImageColorspace

kevin.a.florida (2013-06-15 15:53:56)

I have a better solution for solving inverted colors on php 5.3.x than posted. All the other solutions I found darkens the image or messes with the colors.
See below (note: my imagick object is $jpeg)
$range = $jpeg->getQuantumRange();
$php_vs_arr = preg_split("/\./", phpversion());
$php_vs = $php_vs_arr[0] . '.' . $php_vs_arr[1];
if ($jpeg->getImageColorspace() == Imagick::COLORSPACE_CMYK) {

//make sure cmyk color-space is set correctly
$jpeg->setImageColorspace(12);

// then we add an RGB profile
$icc_rgb = file_get_contents(FRAMEWORK_PATH . DS . 'color' . DS . 'AdobeRGB1998.icc');
$jpeg->profileImage('icc', $icc_rgb);
unset($icc_rgb);

//set color space to rgb
$jpeg->setImageColorspace(13);

//fix gamma, hue, saturation, brightness
if($php_vs < 5.3) {
//ADJUST GAMMA BY 20% for 5.2.x
$jpeg->levelImage(0, 2.0, $range['quantumRangeString']);
} else {
//php 5.3 hack FOR INVERTED COLORS
$jpeg->negateImage(false, Imagick::CHANNEL_ALL);
}

}
$jpeg->stripImage();
//end convert to RGB=========================|

eth at ethaniel dot com (2012-02-28 18:15:08)

When converting from CMYK to RGB using this function, the image can become inverted. To fix this, use a workaround (don't forget to download the .icc files online): 

<?php 
// don't use this (it inverts the image) 
//    $img->setImageColorspace (imagick::COLORSPACE_RGB); 

if ($img->getImageColorspace() == Imagick::COLORSPACE_CMYK) { 
   $profiles = $img->getImageProfiles('*', false); 
   // we're only interested if ICC profile(s) exist 
   $has_icc_profile = (array_search('icc', $profiles) !== false); 
   // if it doesnt have a CMYK ICC profile, we add one 
   if ($has_icc_profile === false) { 
       $icc_cmyk = file_get_contents(dirname(__FILE__).'/USWebUncoated.icc'); 
       $img->profileImage('icc', $icc_cmyk); 
       unset($icc_cmyk); 
   } 
   // then we add an RGB profile 
   $icc_rgb = file_get_contents(dirname(__FILE__).'/sRGB_v4_ICC_preference.icc'); 
   $img->profileImage('icc', $icc_rgb); 
   unset($icc_rgb); 
} 

$img->stripImage (); // this will drop down the size of the image dramatically (removes all profiles) 
?>

mettedraq at gmail dot com (2010-07-01 12:21:28)

This is how to Monochrome a jpg [on Windows].. since I couldn't find it anywhere else.

<?php
header("Content-type: image/jpeg");

$IMagick = new IMagick('c:\\testing\\fruit.jpg');
$IMagick->setImageColorSpace(Imagick::COLORSPACE_GRAY);

echo $IMagick;
?>

charlie at midsouthhost dot com (2010-05-06 21:45:46)

If your getting strange/bad color rendering from a PDF, after trying the colorspace constants noted by jdstraughan, try other values outside that range.
In one case for me only $image->setImageColorSpace(22) provided useful color. I have found posts elsewhere using values up to 255.

jdstraughan dot com at gmail dot com (2008-09-26 12:16:11)

FYI, here is the breakdown for (int $colorspace):
Constants:
0 - UndefinedColorspace
1 - RGBColorspace
2 - GRAYColorspace
3 - TransparentColorspace
4 - OHTAColorspace
5 - LABColorspace
6 - XYZColorspace
7 - YCbCrColorspace
8 - YCCColorspace
9 - YIQColorspace
10 - YPbPrColorspace
11 - YUVColorspace
12 - CMYKColorspace
13 - sRGBColorspace
14 - HSBColorspace
15 - HSLColorspace
16 - HWBColorspace