=================== icc_colorspace Plug-in Readme ==================

----- Introduction
This is a GIMP plug-in for the ICC profile assignment or removal, the 
RGB -> RGB color space conversion and the application of abstract 
profile for image documents.


----- Requirements
This Plug-in requires LittleCMS version 1.15 or later, or, 2.0 or later. 
Bundled win32 binarie is built for a Pentium III or its compatible CPUs. 
These are tested with The GIMP for Windows version 2.6.10.


----- What you need
* GIMP (Version 2.4 or later)

* ICC Profiles
   sRGB profile is included. Standard profiles such as Adobe RGB or 
   ColorMatch RGB is downloadable from Adobe website.

  (Mac)
   http://www.adobe.com/support/downloads/iccprofiles/iccprofiles_mac.html
  (Win/Linux)
   http://www.adobe.com/support/downloads/iccprofiles/iccprofiles_win.html

* Basic knowledge about ICC-based color management


----- How to use
1. Color space (profile) assignment

To assign a color space, select "Image -> Mode -> Assign colorspace" 
from the menu of the image.

After the dialog opens, specify a RGB workspace ("RGB profile" in color 
management preferences) or any profile. To remove the profile that is 
currently assigned, choose "Unassign colorspace".

*To specify any profile, click a button that a profile name is displayed 
to choose from the list, or drop the file icon of profile into the button.

After that, click OK to start assignment (removal).

2. Color space conversion

To convert the color space of an image (into an another RGB space), choose 
"Image -> Mode -> Convert colorspace..." from the menu of the image.

After the open of the dialog, specify the profile of the destination color 
space.

Next, choose the Rendering intent. Generally, "Perceptual" or "Relative 
colorimetric" will do. If these options are chosen, selecting "Use BPC 
algorithm" usually generates better results.


NOTE : "Absolute colorimetric (2)" is an option to reproduce the results 
from Photoshop CS2.
To obtain the same results as any other application or CMMs, choose 
options any other than (2).


If the conversion result contains banding, it is good way to try "Use 
dither" option.

Finally, select "Flatten image" as necessary. The conversion of color 
spaces affects the layer projection because pixel values of each layer 
are modified. In case this effect is not ignorable, We recommend merging 
layers.

After that, click OK to start conversion.

3. Abstract profile application

Abstract profile is a profile that performs color conversion in the Lab 
(CIE L*a*b*) color space, and is generally used for applying effects or 
corrections related to color. As for applications supporting abstract 
profile, not so many are found; ColorSync utility and Photoshop CS4 or 
later supports it.

In Mac OS X several abstract profiles are installed. Also, sample profiles 
comes with a ZIP file of Separate+.

To use abstract profile with an icc_colorspace plug-in, choose "Color -> 
Apply abstract profile..." from image menu.

Specify abstract profile and its target from the dialog, and click OK. 
To apply it for whole active layer, make sure to deselect region and 
then choose "Selection".

For detailed information about the function or operation of icc_colorspace 
plug-in, refer to handbooks about Photoshop or color management.

----- Building and Installing
Same procedure and notes as readme file of Separate+.


----- Future Conception
Some of them may not be feasible...

* Supporting device link profiles
* Simple tool for making abstract profiles
* Conversion using CMM in ICM2.0 (Windows)


----- Author
Yoshinori Yamakawa <yamma-ma at users.sourceforge.jp>

http://cue.yellowmagic.info/softwares/separate-plus/index.html


----- License
This plug-in is licensed under the GNU General Public License version 2.

For more information, see COPYING.
