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);
}
$img->stripImage (); // this will drop down the size of the image dramatically (removes all profiles)
?>
Imagick::setImageColorspace
(PECL imagick 2, PECL imagick 3)
Imagick::setImageColorspace — Establece el espacio de color de una imagen
Descripción
Establece el espacio de color de una imagen. Este método debería emplearse al crear imágenes nuevas. Para cambiar el espacio de color de una imagen existente se debería utilizar Imagick::transformImageColorspace().
Valores devueltos
Devuelve true en caso de éxito.
Errores/Excepciones
Lanza ImagickException en caso de error.
add a note
User Contributed Notes 8 notes
eth at ethaniel dot com ¶
12 years ago
pilot114 at bk dot ru ¶
9 years ago
Simlest way converting from CMYK to RGB:
<?php
if ($jpeg->getImageColorspace() == \Imagick::COLORSPACE_CMYK) {
$jpeg->transformimagecolorspace(\Imagick::COLORSPACE_SRGB);
}
?>
It is pretty work in current stable Image Magick (6.9.0-4).
jdstraughan dot com at gmail dot com ¶
16 years ago
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
kevin.a.florida ¶
11 years ago
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=========================|
Cesare Bordi ¶
6 years ago
These are the basic steps to convert an image from RGB to CMYK:
$image = new Imagick();
$image->readImage(rgb.jpg);
$image->setImageColorSpace(Imagick::COLORSPACE_CMYK);
$image->profileImage('icc', file_get_contents(/path/CoatedFOGRA27.icc'));
$image->negateImage(FALSE, imagick::COLOR_CYAN);
$image->negateImage(FALSE, imagick::COLOR_MAGENTA);
$image->negateImage(FALSE, imagick::COLOR_YELLOW);
$image->negateImage(FALSE, imagick::COLOR_BLACK);
$image->writeImage(cmyk.rgb);
mettedraq at gmail dot com ¶
14 years ago
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 ¶
14 years ago
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.
cesarebordi ¶
6 years ago
These are the basic steps to convert an image from RGB to CMYK:
$image = new Imagick();
$image->readImage(rgb.jpg);
$image->setImageColorSpace(Imagick::COLORSPACE_CMYK);
$image->profileImage('icc', file_get_contents(/path/CoatedFOGRA27.icc'));
$image->negateImage(FALSE, imagick::COLOR_CYAN);
$image->negateImage(FALSE, imagick::COLOR_MAGENTA);
$image->negateImage(FALSE, imagick::COLOR_YELLOW);
$image->negateImage(FALSE, imagick::COLOR_BLACK);
$image->writeImage(cmyk.rgb);
For more information:
http://www.cesarebordi.it/imagemagick-php-convertire-rgb-to-cmyk-web-developer/
