=================== 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.