============================ Separate+ Readme ========================= -Introduction -Requirements -What you need -Installation -How to use -Color separation using devicelink profile -Explanation of Dialogs -Moving together with Configuration -Sample scripts -TIFF Import plug-in -Tips for building plug-ins -Authors -License ----- Introduction Separate+ is the name of a project and plug-in package aimed mainly for complementing color management functionality of GIMP and for assisting publication (Web, printing etc.) activities by utilizing open source software. This package includes the following 3 plug-ins. separate It is a plug-in for RGB -> CMYK conversion, saving and softproofing and is an improved version of Separate plug-in by Alastair M. Robinson. icc_colorspace It is a plug-in for RGB -> RGB conversion and profile management. Another file gives a description of functionalities. separate_import (bonus) It is a plug-in for loading (importing) CMYK TIFF files saved by Separate plug-in. It can also be used for TIFF files created by another application, but the operation is not guaranteed. ----- Requirements The Plug-ins require LittleCMS version 1.15 or later, or, 2.0 or later. Bundled win32 binaries are built for a Pentium III or its compatible CPUs. These are tested with The GIMP for Windows version 2.6.10. ----- What you need * Basic knowledge about ICC-based color management * GIMP (Version 2.4 or later) * Plug-ins included in this package (Windows binary code for GIMP 2.4 or later is attached) * ICC profiles A sRGB profile is included. Standard profiles such as Adobe RGB, SWOP or FOGRA are 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 ----- Installation (Windows) Copy (or move) executable files in "bin\win32" folder into the plug-in folder of GIMP. See Preferences dialog to check the location of the plug-in folder (If there are multiple folders you have to copy only into one folder). For ICC profiles announced in "What you need" section, decompress the ZIP file downloaded and move the decompressed files whose extension is .icc into a predetermined place (following a. or b.). a. Open a window of any folder, input "%COMMONPROGRAMFILES%\Adobe\Color\ Profiles\Recommended" and press Enter key. If you can move to this folder, then put the ICC profiles in this folder. If you find files with the same name, you need neither overwriting nor copying. b. If you cannot find the folder described in a., select and right-click profile icons to display "Install Profile" item in the menu and click it. (Mac OS X) Use MacPorts to build and install GIMP. Start Terminal, move to the folder that was generated by the Separate+ ZIP file decompression, and run the following commands. $ make -f Makefile.macosx $ sudo make -f Makefile.macosx install NOTE : If you use it for GIMP.app, copy separate, separate_import and icc_colorspace generated by the procedure as above into plug-in folder. See Preferences dialog to check the location of the folder. For ICC profiles announced in "What you need" section, decompress the ZIP file downloaded and move the decompressed files whose extension is .icc into a predetermined place. In the case of Mac OS X, the folder is one of the following. a. /Library/Application Support/Adobe/Color/Profiles/Recommended b. /Library/ColorSync/Profiles c. (Home Folder)/Library/ColorSync/Profiles (Linux or UNIX-like operating systems) In the beginning, check whether a GIMP development package is installed. (In the case of Ubuntu, the name is "libgimp2.0-dev".) Additionally, Little CMS (lcms), libtiff and libjpeg development packages are required to be installed; therefore, check it at the same time. Next, modify Makefile by an editor as necessary. Regularly, PREFIX, INSTALLDIR etc. will be modified to fit your environment. Open the terminal window, move to the folder which is generated by the separate+ ZIP file decompression, and run the following commands. $ make $ sudo make install NOTE : If you cannot use sudo, get superuser privilige by "su" and "make install". For ICC profiles announced in "What you need" section, decompress the ZIP file downloaded and move the decompressed files whose extension is .icc into a predetermined place. In the case of Linux, the folder is one of the following. a. /usr/share/color/icc b. ~/.color/icc ----- How to use First, activate a layer you would like to separate. It may unlikely to separate only a specific layer, so you will integrate images regularly. Next, select "Image -> Separate -> Separate" from the menu in the image window. For "Source color space", specify an image profile (if the image has embedded profile, you have only to select "Give priority to embedded profile") , and for "Destination color space", specify a CMYK output profile. If you have any question, contact your printing company. For rendering intent, select "Perceptual" or "Relative colorimetric" (decide from the result which is better). Then, we recommend turning on "Use BPC algorithm". For "Make CMYK pseudo-composite", select if you are planning to tweak after separation. After the above-mentioned specification and clicking OK, a new image with 4 layers is generated. *Additionally, when you created pseudo-composite, the image may contain a background layer; when you separated transparent layers with alpha, the image may contain a copy of the original alpha channel. Each layer corresponds to an individual CMYK color; you can alter it or adjust the tone curve or level if required. Nevertheless, do not change the layer names. In addition, I do not recommend adding or deleting layers or layer masks. If you would like to keep the repairs, save as XCF format (Saving as PSD format eliminates the information about the profile used for the separation). To check the separated color through display screen, Select Image -> Separate -> Proof from the document window of separated image. For "Monitor color space", specify the profile of your monitor. If you need to check the profile, select "View -> Display Filters..." from "Image Window" menu, and after the dialog opens, click "Color Management" filter. Then, the name of the monitor profile is displayed on the lower half of the dialog (You cannot check colors if the configuration is "None"). For "Separated image's color space", choose the profile you specified as destination color space at the separation. Usually, the profile information used for the separation is recorded in the resulting image; therefore, you may select "Give priority to attatched profile". For "Mode", it is difficult to say which is optimum, but Photoshop displays the same as "Normal"; therefore, if you are accustomed to Photoshop's display, select "Normal". After the specification mentioned above, click OK and an image for check is generated. Note that you cannot check in appropriate color if "Color Management -> Mode of operation" in Preferences is "Print simulation". When your check is finished, you can close the window. Finally, export the result to a file. If you would like to separate transparent layers containing alpha and to export them as a TIFF file with preserving the transparent area, make "Alpha of source image" channel displayed in advance. Choose "Image -> Separate -> Export..." from the document window of separated image. Input a path and click "Save" button to complete. Here, you can embed a profile or choose a clipping path. *It is common that profiles are not embedded in images for printing company. ----- Color separation using devicelink profile Turn on "Use devicelink profile" switch in Separate dialog. This operation turns Source color space into Devicelink profile. After that, choose the RGB->CMYK devicelink profile. For the destination, choose a profile which will be attached after the separation (any profile selection does not affect the result of separation). If not needed, it can remain unselected. If you execute it non-interactively, assign a devicelink profile for the 4th parameter (input-profile). For 6th parameter (output-profile), set an empty string or assign a profile attached after the separation (if an empty string, profiles are not attached). ----- Explanation of Dialogs * Separate dialog - Source color space Select an ICC profile that represents the color space of the source image. It is required for making the computer know what color the source image is. Turn on the check box if a profile is embedded. - Destination color space Choose an ICC profile that represents the color space of printed matter. A different profile is provided for different printing condition, so choose the most appropriate one. (The printing condition will be described in the document attached to the profile or web pages of the distributor.) If you are not sure, contact your printing company or profile provider. - Rendering intent See guidebooks about color management. Generally, select either "Perceptual" or "Relative colorimetric" (the final decision should be done after the result). "Absolute colorimetric (2)" makes the results closer to results of "Absolute colorimetric" at Photoshop CS2 or later. If you perform a regular transformation followed by an ICC standard, do not choose this option. - Use BPC algorithm Refer to guidebooks about color management. Unless you have any reason, leave this option on at any time. - Use devicelink profile Select when you perform color separation with a devicelink profile. Novices should not select it (leave this option off at any time). - Preserve pure black It replaces pixels of RGB=0,0,0 with CMYK=0%,0%,0%,100%. - Overprint pure black For the pixels of RGB=0,0,0, it replaces K values with 100%.(CMY values are almost the same as regular converting results.) - Use dither It approximates pixels whose conversion result value cannot be expressed by an 8-bit integer with dithering. When gradation with banding is generated, use dithering and the problem may be improved. *Because this option depends on the function of Little CMS version 1.18, it is not effective in the environment where the Little CMS library of version 1.17 or earlier is installed in. - Make CMYK pseudo-composite Usually, separating results are output in the form of grayscale layer, but selecting this option makes it possible to output colored layer. Use this option when it is convenient for you to check images by layering 4 images such as when modification or minute adjustment is needed after the separation (The advantage of this option is not more than making it possible to check images by layering images). * Proof dialog - Monitor color space Choose the ICC profile of your monitor. If the monitor profile is unknown or lacking, color correction cannot return meaningful result. - Separated image's color space Select a profile assigned at "Destination color space" when the image was separated. - Mode Refer to guidebooks explained about Color settings in Adobe Photoshop. If you check images only on a monitor, leave "Normal". When it is compared with the printed version in appropriate viewing condition, the choice of "Simulate media white" may be good. * Export dialog - Format Choose TIFF, JPEG or Photoshop PSD. If you choose Auto-select mode, the file format is determined based on the extension and then the file is exported (in case the extension is unknown, TIFF format is chosen). - Compress pixel data When this option is turned on, LZW compression is performed for TIFF images, and PackBits compression is performed for Photoshop PSD images. In case of JPEG images, when this option is turned on, compressibility is preceded and this option is turned off, image quality is preceded (Turning off this option do not enable Lossless mode). - Clipping path Choose a path you use as a clipping path. Enabling the clipping path masks outside a path and displays and prints objects on the back. In several applications (such as Scribus), you can specify a clipping path again after placing an image on the page. - Embed color profile Choose an ICC profile embedded in the file. If unnecessary to embed, choose "None". Default CMYK profile and Print simulation profile embed a profile which preferences have specified. Profile used for the separation embeds the profile you used for the color separation. ----- Moving together with Preferences "separate" plug-in acquires the default value of a dialog from Preferences. Following is the correspondence between plug-in items and preference items. Source color space ->RGB profile Destination color space ->CMYK profile Rendering intent -> Softproof rendering intent Monitor color space ->Monitor profile Separated image's color space ->Print simulation profile Proofing mode ->Display rendering intent ("Absolute colorimetric" corresponds to "Simulate media white") NOTE : If any profiles are not assigned in Preferences, the profile that is described in platform.h is used as default as before. If you execute it non-interactively, assigning Profile Path for empty string and both Rendering intent and Proofing mode for -1 to obtain the values of Preferences. ----- Sample Scripts We provide QProof and QExport, which dispense with proofing and file exporting. They automates the processing of merging layers -> separation -> softproofing (exporting). It uses copying and pasting of the visible part, so the original layers are preserved. These scripts acquire the assignments for Destination color space or Rendering intent from Preferences. In addition, Source color space refers to the embedded profile in the original image. For items that are not included in Preferences, assign it on Script dialog. "Real black overprinting..." option performs overprinting processing using active layers. Reasonably, in this time, the colors of this layer are ignored. Copy qproof.scm and qexport.scm into the script folder. (Preferences dialog will inform you the location.) ----- TIFF Import plug-in Installing separate_import(.exe) makes it possible to read CMYK TIFF files under similar conditions to separating with the separate plug-in. Choose Import -> From CMYK TIFF from the menu in the toolbox, and then File Choice dialog opens (in case of GIMP 2.6 or later, from File -> Create -> From CMYK TIFF). ----- Tips for building plug-ins Makefile is provided for Windows, Mac OS X and some other OS such as Linux. You can use it for building. In addition, following information will be of some help. * When you build with Windows, the use of MinGW/MSYS environment is recommended. * platform.h describes the default values of the profile path, so change it as necessary. In addition, iccbutton.c contains a search path of Profile Choice dialog, which should be fundamentally no need to be corrected. * When you build for GIMP2.2, delete "-DENABLE_COLOR_MANAGEMENT" in Makefile or empty macro CM such as "make CM=". In this case, some functions will be invalidated. Note: the support of GIMP2.2 has been stopped after the version 0.5.3. Therefore, the version 0.5.4 or later version may not build for GIMP 2.2. * Building with the header file of Little CMS version 1.17 or earlier disables the option of "Use dither" on the dialog. *Using the header file of version 1.18 or later enables the option choice. In case the version of runtime library is 1.17 or earlier, dithering is disabled. * To use the version 2 family of Little CMS, set the variable USE_LCMS2 at reasonable value to build. You may uncomment the 3rd line of Makefile or run a make command such as "make USE_LCMS2=yes". *At present, LCMS2 does not support dithering; therefore a dithering option is disabled. * If you build on the environment in which multiple versions of GIMP are installed, beware of the location of .pc files that pkg-config command refers. If necessary, configure PKG_CONFIG_PATH environmental variable properly. ----- Authors The Separate+ team Yoshinori Yamakawa <yamma-ma at users.sourceforge.jp> muscovite http://cue.yellowmagic.info/softwares/separate-plus/index.html Localization Alexandre Prokoudine Cédric Gémy Dust Raymond Ostertag Zbigniew MaÅach ZdenÄk HataÅ¡ Authors of original Separate plug-in Alastair M. Robinson Sven Neumann Michael Schumacher Mat Caughron ----- License The plug-ins and scripts included in this package are licensed under the GNU General Public License version 2. For more information, see COPYING.