como configurar modo de cor cmyk no gimp?

[nomade]

Olá, eu suo o Gimp numa impressora Laser Samsung e funciona numa boa, pois uso o software da Samsung (muito bom a Samsung investir em escrever softwares para linux), mas preciso saber como colocar o Gimp no modo de cor CMYK, pois preciso algumas vezes enviar o trabalho pra alguém que vai imprimir em gráfica e lá dizem que em RGB não fica tão bom. Aí eu recebo críticas porque uso o Gimp e não o Photoshop... queria resolver isso e mostrar pra essas pessoas! rsrsrs

Alguém pode me ajudar?

[rjbgbo]

o gimp, ñ trabalha c/ cmky
suas alternativas é fechar o trabalho (imprimir em pdf) no scribus
usar o krita do kde, esse trabalha c/ cmky
fora que tem uns aplicativos p/ isso, que ñ estou lembrado agora, pois sempre fecho publicação em paginador, no caso do linux > scribus
veja também: http://wiki.ubuntu-br.org/DTPnoUbuntu

[nomade]

rjbgbo, agradeço, mas aconselho a não responder caso não saiba sobre o assunto de verdade, porque assim você pode desanimar alguns usuários inciantes e fazer com que eles desistam do Linux... o link que você me passou eu já havia visto.

Pra quem está com o mesmo problema que eu, precisa do plugin separate e dos profiles CMYK do cs4, sigam os passo por aqui http://cue.yellowmagic.info/softwares/separate-plus/index.html pois o Gimp 2.6 pode sim trabalhar com CMYK pois existe a possibilidade de carregar o profile CMYK nas preferências, existem vários tutoriais na internet, mas são meio complexos, procuro apenas a facilidade de estar numa comunidade onde muitas vezes o que você está tentado já foi feito por alguém.

[rjbgbo]

nomade, agradeço a forma 'educada' como vc se dirigiu a mim
acredito que eu tenha um certo conhecimento na área da editoração eletrônica, já de uns bons anos, e também um menor conhecimento do linux, nesse 4 anos de uso.
como ñ tive a preguiça de pesquisar sobre o assunto, do que perguntar em fórum, qdo resolvi testar o linux, também nessa área, foram aos conhecimentos que cheguei
então meu conselho é pesquise, aprenda a fazer a coisa certa, porque a adobe ñ iria produzir softwares paginadores p/ concluir publicações se ñ fosse necessário.
'profissional' que fecha suas publicações em editores de imagem e de desenho vetorial são no mínimo questionáveis.

[nomade]

consegui da seguinte forma, esse é o arquivo readme do Separate
é só seguir os passos no link que postei anteriormente, não tem erro.

============================ 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
                     
           (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 Małach
 Zdeněk Hataš

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.

rjbgbo, ao contrário do que possa ter pensado, não queria lhe ofender ou causar qualquer dano ao possível coleguismo que possamos estabelecer nesse forum. A questão é que acredito que as versões do Gimp anteriores ao 2.6 não apresentavam nenhuma maneira de converter para CMYK, então, possivelmente, você deve ter tomado essa impossibilidade como regra e postado que não há como fazer. Desculpe, mas eu nem mesmo sou designer pra debater sobre os softwares da área com você, nem pretenderia. E não duvido que tenha até maior experiência que eu em GNU/LInux. Sou prestador de serviços, trabalho com divulgação do linux e com suporte a distribuições para Desktop (se um cliente quer fazer algo, eu me mato para conseguir com que ele faça e não mude o sistema).
Na verdade didaticamente me coloquei como detentor do problema, o caso é que a presidente de uma cooperativa usa Ubuntu tem uma impressora laser Samsung e nela os trabalhos saem perfeitos, mas precisa com frequência enviar trabalhos feitos no Gimp para serem imprimidos em outros lugares (na maior parte nada rebuscado, tudo bem simples) e nesse lugares a impressão não sai tão boa, os caras da gráfica disseram que é por causa do modo de cor CMYK (ou ciano, magenta, yelow key).
Eu não fiquei sentado esperando a resposta como sugeriu, e publico a pergunta não só para esclarecer quem tenha o mesmo problema, mas também para trocar idéias sobre o assunto, não vejo problema algum nisso, isso torna a comunidade mais dinâmica, e se procurar coisas que eu postei nessa comunidade e também na comunidade do Satux Linux verá que grande parte das coisas que postei, eu mesmo respondí.

De qualquer forma desculpe qualquer coisa que possa ter ofendido.