Re: [Gimp-developer] Some questions
Am Samstag 12 Februar 2005 13:54 schrieb Sven Neumann: Hello Sven, it's fine to getting aware of the beginning of the cms development in the Gimp! We'll need this stuff :-) Color management on Windows would ideally be implemented using the color management capabilities of the operating system. Same on Mac OS X where ColorSync should be used. For now we will however concentrate on the LCMS based implementation and of course we will make sure that it works on all supported platforms. Hello Sven, like you mentioned before in other cms related threads, it is an good idea to make it possible to choose the CMM the user prefer. And also I thing it would be the best choice to use for default the OS specific build-in CMM, as you said above. Users will be able to load color profiles from whatever location they wish. I don't think we need to provide a way to specify profile directories. GIMP will remember the last location you loaded profiles from and if you need to use multiple profile directories, it's easy to add bookmarks for them. That's a very good point, and it comes with the behavior we should keep in touch with: A very flexible implementation of cms into the gimp. I like this idea. This goes however way too much into details yet. We can figure out such usability concerns as soon as the basic framework has been put in place. When do you expect the basic framework will be up for discussions regarding the usability? ICC profiles can be stored in TIFF files. The parasite is just the way that GIMP deals with this information. I don't know off the top of my head if JPEG allows to embed ICC profiles. Since I would rather get back to work on the color management implementation, I kindly ask you to look that up in the JPEG spec yourself. Yes, JPEG (JFIF) allows to embed ICC profiles. Also it's possible to choose CMYK as colormodel. At least JPEG2000 support this, and Photoshop is able to save normal jpeg files with an icc profile and in CMYK. It support's also clipping paths.[1] http://developer.gimp.org/standards.html has some links that you might find useful. If you know of any URLs that should be added there, let me know. It may would be useful to make a special section colormanagement, and point for example to color.org fogra.org eci.org http://www.swop.org/specifications.html etc. Kind regards Gerhard [1] http://www.jpeg.org/apps/prepress.html?langsel=en http://www.wotsit.org/search.asp?page=5s=graphics http://www.boscarol.com/pages/cms_eng/065-icc.html http://www.google.de/search?hl=deie=ISO-8859-1q=jfif+cmyk+icc+site%3Acolor.orgbtnG=Suchemeta= ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
Re: [Gimp-developer] Some questions
Hi, Jordi Cantn [EMAIL PROTECTED] writes: How can a plugin have access to this preferences? They cannot yet. I have a suggestion. I think that it will be useful if a new folder list for ICC profiles could be also included in the preferences dialog. The default ones could be: $prefix/share/gimp/2.0/color $user/.gimp-2.3/color The original patch that I applied to HEAD did have this option but I removed it since I think we should rather use the established locations for ICC profiles that are shared between apps. I have noticed that parasites are saved/restored from file depending on the file format used. (for example in tiff they work and in jpg not). I assume that it is not a bug, but a limitation of the graphic format itself. Is this theory true? Parasites can only stored in XCF files. Sven ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
Re: [Gimp-developer] Some questions
Sven Neumann wrote: How can a plugin have access to this preferences? They cannot yet. ok. The original patch that I applied to HEAD did have this option but I removed it since I think we should rather use the established locations for ICC profiles that are shared between apps. You mean /usr/share/color/icc and ~/.color/icc ? What about running Gimp on windows? I think that it could be useful if that user can add additional profiles directories to the default ones. Think about advanced users that could have a lot of specific profiles depending on the situation. I have noticed that parasites are saved/restored from file depending on the file format used. (for example in tiff they work and in jpg not). I assume that it is not a bug, but a limitation of the graphic format itself. Is this theory true? Parasites can only stored in XCF files. But I have checked that the "icc-profile" parasite can be recovered from a Tiff file, but not from a jpg file. I assume that "icc-profile" parasite can be stored in tiff, but not in jpg. Am I right? -- Jordi Cantn http://www.virtual-sub.org
Re: [Gimp-developer] Some questions
Hi, Jordi Cantn [EMAIL PROTECTED] writes: You mean /usr/share/color/icc and ~/.color/icc ? What about running Gimp on windows? Color management on Windows would ideally be implemented using the color management capabilities of the operating system. Same on Mac OS X where ColorSync should be used. For now we will however concentrate on the LCMS based implementation and of course we will make sure that it works on all supported platforms. I think that it could be useful if that user can add additional profiles directories to the default ones. Think about advanced users that could have a lot of specific profiles depending on the situation. Users will be able to load color profiles from whatever location they wish. I don't think we need to provide a way to specify profile directories. GIMP will remember the last location you loaded profiles from and if you need to use multiple profile directories, it's easy to add bookmarks for them. This goes however way too much into details yet. We can figure out such usability concerns as soon as the basic framework has been put in place. But I have checked that the icc-profile parasite can be recovered from a Tiff file, but not from a jpg file. I assume that icc-profile parasite can be stored in tiff, but not in jpg. ICC profiles can be stored in TIFF files. The parasite is just the way that GIMP deals with this information. I don't know off the top of my head if JPEG allows to embed ICC profiles. Since I would rather get back to work on the color management implementation, I kindly ask you to look that up in the JPEG spec yourself. http://developer.gimp.org/standards.html has some links that you might find useful. If you know of any URLs that should be added there, let me know. Sven ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
Re: [Gimp-developer] Some questions
Hi, On Sat, 12 Feb 2005 13:54:39 +0100, Sven Neumann [EMAIL PROTECTED] wrote: Color management on Windows would ideally be implemented using the color management capabilities of the operating system. Same on Mac OS X where ColorSync should be used. For now we will however concentrate on the LCMS based implementation and of course we will make sure that it works on all supported platforms. My understanding (please correct me, I don't have personal experience of this) is that the windows CMS is (or was?) rather broken: that was one of Marti Maria's original motivations for the development of LCMS. The apple one is supposed to be better, but there are some benefits to having the same CMS on all platforms. ICC profiles can be stored in TIFF files. The parasite is just the way that GIMP deals with this information. I don't know off the top of my head if JPEG allows to embed ICC profiles. Since I would rather get back to work on the color management implementation, I kindly ask you to look that up in the JPEG spec yourself. You can embed ICC profiles in JPEG files. The lcms distribution contains code to insert and extract profiles: check the sources for jpegicc and friends. John ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
Re: [Gimp-developer] Some questions
On Feb 12, 2005, at 11:13 AM, John Cupitt wrote: Hi, On Sat, 12 Feb 2005 13:54:39 +0100, Sven Neumann [EMAIL PROTECTED] wrote: Color management on Windows would ideally be implemented using the color management capabilities of the operating system. Same on Mac OS X where ColorSync should be used. For now we will however concentrate on the LCMS based implementation and of course we will make sure that it works on all supported platforms. My understanding (please correct me, I don't have personal experience of this) is that the windows CMS is (or was?) rather broken: that was one of Marti Maria's original motivations for the development of LCMS. The apple one is supposed to be better, but there are some benefits to having the same CMS on all platforms. This is what Adobe does: They ship their own CMS with their products. They do however give you a choice of using the native CMS. All CMS will give slightly different results when you compare their output. For consistency purposes, it makes sense for an application to use the same CMS on all platforms if the app is available on multiple platforms. Karl Heinz ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
Re: [Gimp-developer] Some questions
On Saturday 12 February 2005 08:13, John Cupitt wrote: On Sat, 12 Feb 2005 13:54:39 +0100, Sven Neumann [EMAIL PROTECTED] wrote: Color management on Windows would ideally be implemented using the color management capabilities of the operating system. Same on Mac OS X where ColorSync should be used. For now we will however concentrate on the LCMS based implementation and of course we will make sure that it works on all supported platforms. My understanding (please correct me, I don't have personal experience of this) is that the windows CMS is (or was?) rather broken: This is still correct. Window CMS is basicly broken and applications implement CMS is what amounts to pockets of fuctionality. So on Windows I use Photoshop's CM and Adobe gamma to implement my CMS. I even turn off the CM functions in my printer drivers because these are not usable for serious CM work as it is to hard to predict what it will do. So all Windows has at this time is a frame work for where profiles are stored. I think we can do much better. -- Hal V. Engel pgpboJuq7ZTWa.pgp Description: PGP signature
Re: [Gimp-developer] Some questions
Hi, Karl Heinz Kremer [EMAIL PROTECTED] writes: All CMS will give slightly different results when you compare their output. For consistency purposes, it makes sense for an application to use the same CMS on all platforms if the app is available on multiple platforms. Fully understood. The point was not to necessarily use the CMS of the underlying operating system but to not tie us into a particular CMS. The framework, that is being worked on, should allow for different implementations. We will use lcms for the default implementation and it should work on all supported platforms. The goal is though to allow people to develop alternative implementations, based on other CMS or perhaps simply with different policies. As soon as we have extened the modules and plug-ins API as described, you will be able to develop a different color management implementation without doing any modifications to the GIMP core. Sven ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
Re: [Gimp-developer] Some questions
On Friday 11 February 2005 15:24, Jordi Cantón
wrote:/usr/local/share/Scribus/profiles
I have a suggestion. I think that it will be useful if a new folder
list
for ICC profiles could be also included in the preferences
dialog. The
default ones could be:
$prefix/share/gimp/2.0/color
$user/.gimp-2.3/color
I think it would be better if the color directories were not version or
app specific and also not hidden. I know that both the OpenICC and
lcms-users list have talked about this at least in terms of a standard
for a system wide directory for color profiles. This is also more of
a path kind of thing where profiles should be searched first in the
users color profile directory then the system directory.
Scribus uses /usr/local/share/Scribus/profiles for it's system wide
profile directory. I do not know where other open source apps that
have CM put their profiles. These include CinePaint and
GraphicMagick. If GIMP uses $prefix/share/gimp/2.0/color and every
other app has it's own location we will have created a mess. In
particular version specific directories should be avoided.
Here is what was said on the lcms list in May 2004 by Bob Friesenhahn
[EMAIL PROTECTED] in response to a note by Stuart Nixon
[EMAIL PROTECTED]:
To get widespread usage of ICCs and CMS engines under Linux, we
need a couple of things:
1.A standard system profile directory. I believe
a directory has already been proposed although I can't find the
original email.
While it may be possible to establish a standard directory for
Linux, the solution should be OS-agnostic. That means that the
standard shared directory should be relative to the software
installation prefix. When installing on a proprietary OS, the base
installation prefix is likely not '/'. The standard default for open
source apps is to install under '/usr/local' in order to avoid
accidentally corrupting the OS. A path like
${prefix}/share/cms/profiles would be ideal.
The reason why I suggest that an XML configuration file be used
(similar to the way fonts are handled under Red Hat) is this allows
multiple applications to be configured via one common file.
3.There should be a way to get the current monitor profile for
each display, so that applications can ask the system for this
profile and use it, rather than having to ask the user
for the profile name. It should handle multiple displays
Yes. This configuration should be supported both at the
system/network level and at the user level so that the user may
override or extend the defaults.
-- end of lcms list quote ---
I think that it would be a good idea to try to get some of those on the
lcms list and the OpenICC list involved so that things that are done
on GIMP will at least be close to fitting into the eventual system
wide color management frame work.
In addition GIMP is used on Windows and Mac computers which already
have standard locations for the system color management directories.
In the case of the Mac I am making an assumption that this is the
case. I am not a Mac user so I have no idea how this is structured on
a Mac. But I do have significant CM experience on Windows. So I can
help with this.
--
Hal V. Engel
pgpFq1pJaOoI9.pgp
Description: PGP signature
