Re: [Gimp-developer] jpeg-exif continued

2005-01-15 Thread Sven Neumann
Hi,

William Skaggs [EMAIL PROTECTED] writes:

 Sven:
 What is akward about it? 

 Passing, say, an ExifData struct to a plug-in is awkward.  Calling a
 function and giving it a pointer is simpler, and much faster too.
 And then there's all the extra baggage of registering a plug-in etc.

I agree that for a C plug-in a library is easier to use but we will
also have to care about plug-ins written in other languages. Making
the functionality available in the PDB solves this nicely. What we
usually do is to provide wrappers that let the procedure call appear
as a simple function call.

 Sven:
 The JPEG plug-in would have to change the orientation tag if it's
 rotating the image on load, wouldn't it? It would have to do that
 before calling gimp_metadata_store_exif().

 It can do that if it wants to, but there is no requirement.  The
 orientation needs to be set to top-left when an image is saved,
 but it doesn't really matter whether the change is made upon loading
 or upon saving.  If nothing else, doing it on saving prevents the
 user from setting things incorrectly in the metadata editor.

Well, how is the save plug-in supposed to know that it needs to change
the orientation field upon saving? Only when the image is rotated,
during load, is this information available. Or am I missing something
here?


Sven
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Re: [Gimp-developer] jpeg-exif continued

2005-01-15 Thread Sven Neumann
Hi,

Robert L Krawitz [EMAIL PROTECTED] writes:

 I know I've been making a nuisance of myself about this, but PLEASE
 at least provide a way to turn this query off.

Robert, we are at the very beginning of the development cycle and are
discussing the basics. The query is off-topic right now.


Sven
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[Gimp-developer] mbox archive of [gimp-devel] 2004 and 2005

2005-01-15 Thread Gerhard Gaußling
Hello,

I subscribed today to gimp-developers, and I need at least the archives 
for January 2005 in mbox format (b- or gziped).
  http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer has got 
only the archives until 2003.

Thank you  

Kind regards 

Gerhard Gaußling
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Re: [Gimp-developer] jpeg-exif continued

2005-01-15 Thread William Skaggs

Sven:
 I agree that for a C plug-in a library is easier to use but we will
 also have to care about plug-ins written in other languages. Making
 the functionality available in the PDB solves this nicely. What we
 usually do is to provide wrappers that let the procedure call appear
 as a simple function call. 

This is only relevant to file plug-ins.  It didn't occur to me that
they would ever be written in anything except C, but if that is a 
reasonable possibility, then I accept the argument.

Sven:
 Well, how is the save plug-in supposed to know that it needs to change
 the orientation field upon saving? Only when the image is rotated,
 during load, is this information available. Or am I missing something
 here? 

The orientation is *always* supposed to be set to top-left when an
image is saved, on the principle that after the user has edited
the image in GIMP, the orientation is the way the user wants it.
Only a camera should ever set it to anything other than top-left.

  -- Bill
 

 
__ __ __ __
Sent via the CNPRC Email system at primate.ucdavis.edu


 
   
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Re: [Gimp-developer] mbox archive of [gimp-devel] 2004 and 2005

2005-01-15 Thread William Skaggs



Gerhard Gau�ling wrote:
 I subscribed today to gimp-developers, and I need at least the archives
 for January 2005 in mbox format (b- or gziped).
  http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer has got
 only the archives until 2003.

It's broken.  See

http://www.gimp.org/mail_lists.html

for other archives.

Best,
  -- Bill



__ __ __ __
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Re: [Gimp-developer] mbox archive of [gimp-devel] 2004 and 2005

2005-01-15 Thread Gerhard Gaußling
Am Samstag 15 Januar 2005 18:07 schrieb William Skaggs:
 It's broken.  See

 http://www.gimp.org/mail_lists.html

 for other archives.

Hello Bill,

Thank you for the hint, but unfortunately there is nothing to find for 
downloading in mbox format :-(

regards

Gerhard
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[Gimp-developer] Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Gerhard Gaußling
Sven Neumann wrote:

 If we don't convert the image at load time, all plug-ins that change
 colors would have to be aware of the color-space the image is in.
 Since this is not the case for the time being, it would probably be a
 bad idea to not convert the image. As soon as we go further down the
 road and have all plug-ins as GEGL ops, this will change. But for the
 time being, I don't see much choice but to convert everything to sRGB.
 Note that we are just talking about the first step here. Something
 that we can achieve in the next few months, without changing each and
 every piece of code in GIMP and it's plug-ins.

Hello Sven,

Sorry for breaking the thread, but I was not able to find this message as
mbox-archiv. 

I think that the suggestions made by Hal V. Engel and Jan-Peter Homann (a
well known color management consultant in Germany, afair also a member of
the eci.org maillist, a very good resource for cms knowledge)are very
important for a professional color management in the GIMP.

I'm not a Programmer, but isn't it possible to make a plug-in which load's
the icc information at a first step, to offer the user the ability to
decide in which way he wants to handle the file regarding it's color space?

After this step the file will be converted into the choosed colorspace[*]
and then loaded into the gimp, displayed in the working colorspace,
corrected by the monitor profile, with the possibility to choose a color
proof view with a selectable icc profile for the soft proof.

Please, correct me if I'm wrong.

[*]
a. no colormanagement 
b. working colorspace (imho don't offer the user the ability to preselect
the working color space in the preferences and instead convert all files
into sRGB is the worst we can do) 
c. apply an icc profile and then as a suboption 
c1. convert it into the working color space.

For Gimp-print we can handle the icc like Jan-Peter Homann suggested.

I agree, that this behavior would be very close to the behavior of adobe
photoshop regarding color-management, which got imho a very good
implementation of a colormanagement for professional needs.

There are good starting points by Alastair M.Robinson blackfive [ a t ]
fakenhamweb.co.uk. 

He made a good start of such a plugin with it's 'separate' plugin:
http://www.blackfiveservices.co.uk/separate.shtml
He send me a copy of an improved version for gimp 2.x . 

Please see this thread in gimp user:
http://article.gmane.org/gmane.comp.video.gimp.user/6008

He also works on a programm called photoprint:
http://www.blackfiveservices.co.uk/photoprint.shtml
based on guten print for gimp. (GIMP-Print/GutenPrint version 5 (beta 2))

for example photoprint..

quote
o Can apply ICC colour profiles, with selectable rendering intent.
 
o Can generate rough-cast ICC colour profiles, given RGB Primary
chromaticity coordinates (x,y), Gamma values and White Point.
 
o Can read and use an embedded colour profile (currently TIFF only).
/quote

He's working on CMYK support implemented with Argyll:

quote
Coming soon:
Support for CMYK images and profiles (useful in combination with Argyll),
and widgets for dealing with physical dimensions.
[...]
CMYK images are not yet properly supported, but I intend to support these in
future.
/quote

I think it's very important for the future of the gimp, to handle color
management in a proper and professional way, to get it on a professional
level also for pre-press image processing. 

Is there an existing roadmap for this issue?

Thank you

Gerhard Gaussling

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Re: [Gimp-developer] jpeg-exif continued

2005-01-15 Thread Sven Neumann
Hi,

William Skaggs [EMAIL PROTECTED] writes:

 I agree that for a C plug-in a library is easier to use but we will
 also have to care about plug-ins written in other languages. Making
 the functionality available in the PDB solves this nicely. What we
 usually do is to provide wrappers that let the procedure call appear
 as a simple function call. 

 This is only relevant to file plug-ins.  It didn't occur to me that
 they would ever be written in anything except C, but if that is a 
 reasonable possibility, then I accept the argument.

It's just an argument, not a requirement. Simply something that might
be worth keeping in mind. Is this really only relevant to file
plug-ins? A metadata editor would need to use these functions as well,
wouldn't it?

 The orientation is *always* supposed to be set to top-left when an
 image is saved, on the principle that after the user has edited
 the image in GIMP, the orientation is the way the user wants it.
 Only a camera should ever set it to anything other than top-left.

Hmm, so if I open an image, do some color corrections, but do not
rotate it, the orientation tag is supposed to change? I can hardly
believe that. But if you say that's what the spec says...


Sven
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Re: [Gimp-developer] Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread David Neary
Hi Gerhard,

Gerhard Gaußling wrote:
 I'm not a Programmer, but isn't it possible to make a plug-in which load's
 the icc information at a first step, to offer the user the ability to
 decide in which way he wants to handle the file regarding it's color space?

It would be possible to do the following:

- load image's raw data, and ICC profile
- During display, convert from source colorspace to display
  colorspace
- During saving, save the originally loaded ICC profile back to
  file, if the format supports it, or convert to sRGB if it
  doesnt.

The problems with that approach are

- Lots of elements in the GIMP are not colorspace aware - for
  example, you would have to modify the paint tools to detect
  whether there was an ICC profile associated with a display they
  were painting to, and color convert the (sRGB) data that they 
  are painting. This is not possible currently, and Sven has
  expressed a desire that color management be kept out of the
  core in the past.
- Data which enters the image from other sources (copy  paste
  from another image, for example) may have been in a different 
  colorspace, requiring convertion or some other funkiness to 
  keep things coherent inside the image

 After this step the file will be converted into the choosed colorspace[*]
 and then loaded into the gimp, displayed in the working colorspace,
 corrected by the monitor profile, with the possibility to choose a color
 proof view with a selectable icc profile for the soft proof.

We currently have the ability to do color proofs with external
ICC profiles. THe interface to the loading of the profiles isn't 
perfect yet, but it's there.

Cheers,
Dave.

-- 
David Neary,
Lyon, France
   E-Mail: [EMAIL PROTECTED]
CV: http://dneary.free.fr/CV/
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Re: [Gimp-developer] Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Sven Neumann
Hi,

Gerhard Gauling [EMAIL PROTECTED] writes:

 I think that the suggestions made by Hal V. Engel and Jan-Peter
 Homann (a well known color management consultant in Germany, afair
 also a member of the eci.org maillist, a very good resource for cms
 knowledge) are very important for a professional color management in
 the GIMP.

Sure, noone questioned that.

 I think it's very important for the future of the gimp, to handle
 color management in a proper and professional way, to get it on a
 professional level also for pre-press image processing.

Ditto.

 Is there an existing roadmap for this issue?

No, we are only just in the process of making one.


Sven
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Re: [Gimp-developer] Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Sven Neumann
Hi,

David Neary [EMAIL PROTECTED] writes:

  ...Sven has expressed a desire that color management be kept out of
  the core in the past.

You misunderstood me then. Managing colors does of course belong into
the core but I would like to keep the implementation out of the core.
The idea is to be able to use different color management systems and
not to restrict ourselves to lcms. GEGL seems to offer just the right
level of abstraction that would be needed here. That's why it seems
like a nice idea to use it.


Sven
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[Gimp-developer] Re: Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Gerhard Gauling
Hello David,

BTW: Using the gmane.org newsserver and a news client seems to be a good
alternative to the mbox archive ;-).

David Neary wrote:

 [...]
 Gerhard Gaußling wrote:
 I'm not a Programmer, but isn't it possible to make a plug-in which
 load's the icc information at a first step, to offer the user the ability
 to decide in which way he wants to handle the file regarding it's color
 space?
 
 It would be possible to do the following:
 
 - load image's raw data, and ICC profile
 - During display, convert from source colorspace to display
   colorspace

If you apply a conversion to the file there will be a loss of color
information, so it's necessary, that we avoid unneeded conversions to the
original file.

For example, if you convert from adobeRGB into sRGB and viceversa several
times, you wouldn't receive the original color impression never more, it's
lost, and there for in poor quality (comparable with the jpeg lossy
compression, keep that in mind).

So, we have to convert only the displayed version of the data, not the
original data (Jan-Peter, Hal and others, please correct me if I'm wrong).  

This is important, to get a display color as closed to the original scene in
nature as possible, adjusted to the display hardware by the measured or
proofed monitor profile.

While rendering the data for the display this way, the data itselves stays
in working color space, or original color space (as choosen by the user
while opening the file). 

It should be saved with the working color space e.g. as device independant
suggested by ECI.org eciRGB.icc, which is comparable with widegammut and
adobeRGB, or the original color space (as choosen by the user while opening
the file), to avoid unneeded conversions while saving the data. 

eciRGB.icc offers a wider range of colors compared to sRGB, which got a very
limited color space, so it avoids clipping, when converting e.g. from
scanner profiles to the working color space.

The user should archive the data in the recommended device independent
colorspace (e.g. for Europe according to the suggestion of the ECI in
eciRGB color space [1]).

To Print the data it should be converted to the printer profile (This should
happen in the service bureau or the printer service, maybe the printer
offers you the printer-device profile to do the conversion by yourself. At
home you can measure your inkjet profile for example, and apply that.)

If you want to save your work for web you should do that by using the
conversion from (the wider) working color space to sRGB the default for
webpublishing.

 - During saving, save the originally loaded ICC profile back to
   file, if the format supports it, or convert to sRGB if it
   doesnt.

This all should be flexible and interactive (there could be an easy mode
coosen in the preferences to disable colormanagement at all), and it's
important to retain as much original color informations than possible.

 
 The problems with that approach are
 
 - Lots of elements in the GIMP are not colorspace aware - for
   example, you would have to modify the paint tools to detect
   whether there was an ICC profile associated with a display they
   were painting to, and color convert the (sRGB) data that they
   are painting. This is not possible currently, and Sven has
   expressed a desire that color management be kept out of the
   core in the past.

Okay, so I assume, that my (and Hal's and Jan-Peter's) suggestions have to
wait for the release after GEGL? For a new rendering-engine further to
GEGL? GIMP 3.0?

I want only remember the developers that there is already a state of the art
color-management used by the printing industry, which the GIMP-developers
can't ignore while implementing colormanagement and CMYK or
multichannel/DeviceN mode for the GIMP. Just avoid to go into the wrong
direction when going further with the implementation of colormanagement.   

 - Data which enters the image from other sources (copy  paste
   from another image, for example) may have been in a different
   colorspace, requiring convertion or some other funkiness to
   keep things coherent inside the image

Photoshop lets pop up a dialog where the user can decide the kind of
conversion he will do for the pasted/dragged image.
 
 After this step the file will be converted into the choosed colorspace[*]
 and then loaded into the gimp, displayed in the working colorspace,
 corrected by the monitor profile, with the possibility to choose a color
 proof view with a selectable icc profile for the soft proof.
 
 We currently have the ability to do color proofs with external
 ICC profiles. THe interface to the loading of the profiles isn't
 perfect yet, but it's there.

Desired is a 'On the fly' Softproof.

I admit, that this is a very complex subject, and it is much work to
implement all this color stuff into the GIMP, but I'm shure it's worth it.

Thank you

Gerhard


[1]http://www.eci.org/eci/en/044_working_colour_spaces.php
   

Re: [Gimp-developer] Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Hal V. Engel
On Saturday 15 January 2005 13:21, David Neary wrote:
 Hi Gerhard,
 
 Gerhard Gaußling wrote:
  I'm not a Programmer, but isn't it possible to make a plug-in which 
load's
  the icc information at a first step, to offer the user the ability 
to
  decide in which way he wants to handle the file regarding it's 
color space?
 
 It would be possible to do the following:
 
 - load image's raw data, and ICC profile
 - During display, convert from source colorspace to display
   colorspace
 - During saving, save the originally loaded ICC profile back to
   file, if the format supports it, or convert to sRGB if it
   doesnt.

I am not sure that the image should be converted to sRGB if the file 
format does not support embedded profiles.  For one thing how likely 
is it that someone would open an image in a file format that had an 
embedded profile would then save the file in a format that did not 
support an embedded profile.  The other reason that I have for this 
reservation is that many of us have printers that have more gamut than 
sRGB supports.  sRGB is OK, even preferred, for web work and for those 
that are working with low gamut printers, such as CMYK offset 
printers, but my feeling is that it is too limited for those that have 
wider gamut printers like the 6 and 7 color Epson or HP printers for 
example.  That is one of the reasons that Photoshop defaults to the 
AdobeRGB color space, which is a medium wide gamut color space, as 
this has enough gamut to fully support these wider gamut printers.  If 
the GIMP is going to use a default color space this should not be a 
low gamut color space like sRGB.  

On the other hand anyone working with image file formats that do not 
support embedded profiles should have color management turned off.  So 
perhaps someone can convince me that this is the correct thing to do.  
I think it would be useful for this list to talk about how The GIMP 
will work with color management turned on and with it turned off.  As 
these 2 configurations will be used by users that are working at very 
different levels of expertise and with significantly different 
expectations.

 
 The problems with that approach are
 
 - Lots of elements in the GIMP are not colorspace aware - for
   example, you would have to modify the paint tools to detect
   whether there was an ICC profile associated with a display they
   were painting to, and color convert the (sRGB) data that they 
   are painting. This is not possible currently, and Sven has
   expressed a desire that color management be kept out of the
   core in the past.

At this point nothing in The GIMP is color aware other than the 
proofing plugin.  So should every plugin need to do color conversions 
to the display color space or should this be handled in one place?  
Since current plugins know nothing about color management and color 
spaces should we be making assumptions about what color space these 
are working in (some plugin authors may have assumed sRGB but have all 
of them)?  

Since I have not looked at the code I do not know what should and 
should not be in the core.  But perhaps some color management 
functionality belongs in the core.  But I will let those that know how 
the application is structured work this out.  But it seems to me that 
the core could have a high level color management interface that 
abstracts this to hide the specific implementation details.  Then the 
core could map these to a specific implementation using LCMS, Argyll 
or some other CMS library.  Perhaps this is what Sven had in mind.


 - Data which enters the image from other sources (copy  paste
   from another image, for example) may have been in a different 
   colorspace, requiring convertion or some other funkiness to 
   keep things coherent inside the image

Yes is is exactly correct.  When we copy from image A in color space X 
to image B in color space Y the image data coming from A must be 
converted from color space X to color space Y.  To do anything else 
would not be correct.

 
  After this step the file will be converted into the choosed 
colorspace[*]
  and then loaded into the gimp, displayed in the working colorspace,
  corrected by the monitor profile, with the possibility to choose a 
color
  proof view with a selectable icc profile for the soft proof.
 
 We currently have the ability to do color proofs with external
 ICC profiles. THe interface to the loading of the profiles isn't 
 perfect yet, but it's there.
 
 Cheers,
 Dave.
 
 -- 
 David Neary,
 Lyon, France
E-Mail: [EMAIL PROTECTED]
 CV: http://dneary.free.fr/CV/
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pgpQLbz5BjoR9.pgp
Description: PGP signature


Re: [Gimp-developer] Re: Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Sven Neumann
Hi,

Gerhard Gauling [EMAIL PROTECTED] writes:

 Okay, so I assume, that my (and Hal's and Jan-Peter's) suggestions have to
 wait for the release after GEGL? For a new rendering-engine further to
 GEGL? GIMP 3.0?

Why? Almost everything you listed can already be done in GIMP.  It's
just a bit akward to do it from a user interface point of view and
that's what we want to improve for GIMP 2.4.

 Desired is a 'On the fly' Softproof.

Could you explain what you mean by on the fly softproof and how that
is any different to the softproof that's available?


Sven
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[Gimp-developer] Re: Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Gerhard Gaußling
Sven Neumann wrote:

 You misunderstood me then. Managing colors does of course belong into
 the core but I would like to keep the implementation out of the core.
 The idea is to be able to use different color management systems and
 not to restrict ourselves to lcms. GEGL seems to offer just the right
 level of abstraction that would be needed here. That's why it seems
 like a nice idea to use it.

That's a good point, also because in the lcms-user maillist there was a
thread about Fast colour managed preview, how? , where Gerhard Fuernkranz
pointed out, that Argyll's IMDI routines are _very fast_ with 8bpp input:
http://sourceforge.net/mailarchive/forum.php?thread_id=6213268forum_id=1912 .

regards

Gerhard

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Re: [Gimp-developer] Re: Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Hal V. Engel
On Saturday 15 January 2005 14:42, Gerhard Gaußling wrote:
snip 
 For example, if you convert from adobeRGB into sRGB and viceversa 
several
 times, you wouldn't receive the original color impression never more, 
it's
 lost, and there for in poor quality (comparable with the jpeg lossy
 compression, keep that in mind).
 
 So, we have to convert only the displayed version of the data, not 
the
 original data (Jan-Peter, Hal and others, please correct me if I'm 
wrong).  

This is exactly correct.  The conversion between color spaces will 
always introduce quantization errors.  If only one conversion is done 
these have a minimal effect on the image assuming the the gamut of the 
original fits into the new color space with minimal loses.  This is 
not likely to be the case when converting from a wider space such as 
AdobeRGB to a narrow space like sRGB.  But if this happens many times 
the image will suffer significant degradation.  In other words the 
color space conversion is NEVER lossless.


 Okay, so I assume, that my (and Hal's and Jan-Peter's) suggestions 
have to
 wait for the release after GEGL? For a new rendering-engine further 
to
 GEGL? GIMP 3.0?

I am not sure that I want to wait that long but if it will take that 
long to get it right then so be it.  I would rather wait and get a 
correct implementation then get an incorrect one sooner.  But I think 
that it should be possible to do at least some of this sooner.  For 
example perhaps a color aware printer interface could be added sooner 
by leveraging Alastair M.Robinson work on PhotoPrint. 
 

  We currently have the ability to do color proofs with external
  ICC profiles. THe interface to the loading of the profiles isn't
  perfect yet, but it's there.
 
 Desired is a 'On the fly' Softproof.

I have little use for soft proofs since my custom profiled printer 
gives results that are almost identical to what I see on the screen in 
Photoshop.  But for those that are working with low gamut printers 
this is likely more useful. 
 
 
 I admit, that this is a very complex subject, and it is much work to
 implement all this color stuff into the GIMP, but I'm shure it's 
worth it.
 

I would also like to add that although I am not a color management 
professional I did struggle with color issues in my digital darkroom 
and as a result I have spent many hours setting up a proper (but 
perhaps somewhat basic) color management work flow.  In the process I 
studied many sources and learned a lot.  Gerard is correct this is not 
going to be trivial and it will take a lot of effort to get this in 
place.  

For those that are new to color management and would like to understand 
this better from a CM users perspective I would like to recommend that 
a good starting point is 
http://www.normankoren.com/color_management_2.html#Implementation%3C/A%3EHere,
%20you%20helped%20me,
%20again!%20%20I%20am%20learning%20how%20to%20do%20the  This web site 
is from a color management users perspective and it starts out with a 
basic overview of how color management works and what all of the 
pieces are and how they all work together.  He give examples of how to 
setup things in both Photoshop and Picture Window Pro.  So this has 
lots of info about how two different apps have set up the user 
interface for this.  

Also one of the interesting things on this site is that he has the 
GretagMacbeth ColorChecker test pattern in both SMPTE-240M (same as  
AdobeRGB 1998) and sRGB color spaces.  One of the patches (out of 24) 
is out of gamut in the sRGB version of the image but is in gamut in 
the SMPTE-240M image.

-- 
Hal V. Engel


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[Gimp-developer] Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Gerhard Gaußling
Hello Sven,

thank you for your reply!

Sven Neumann wrote:

 Gerhard Gaußling [EMAIL PROTECTED] writes:
 
 Okay, so I assume, that my (and Hal's and Jan-Peter's) suggestions have
 to wait for the release after GEGL? For a new rendering-engine further to
 GEGL? GIMP 3.0?
 
 Why? Almost everything you listed can already be done in GIMP.  It's
 just a bit akward to do it from a user interface point of view and
 that's what we want to improve for GIMP 2.4.

This is good to hear!
 
 Desired is a 'On the fly' Softproof.
 
 Could you explain what you mean by on the fly softproof and how that
 is any different to the softproof that's available?
 

What kind of softproof is available? Hmm.. I can nothing similar find here. 

I got under Image  Separate  Proof the possibility of an Softproof (plug
in 'separate' by Alistair M. Robinson). It shows up a dialog which asks me
the Source Profile /usr/lib/scribus/profiles/AdobeRGB1998.icc and the
Destination Profile
/usr/lib/scribus/profiles/USWebCoatedSWOP.icc (defaults, should be
eciRGB.icc and isocoated.icc according to eci.org [1]) and the checkboxes
Preserve Pure Black and Overprint Pure Black. If I press OK I got the
message-dialog PROOF IMAGE Image is not separated So I have to
separate the image first into cmyk mode by the plugin 'separate'. That's
not a Softproof 'on the fly'.

So I have to seperate the image first. I do it with the default profiles. A
new image with the CMYK separated RGB shows up (5 layers, 4 layers CMYK
mode 'darken only' 1 Background, Image in RGB Mode, if I save that it will
be saved as cmyk tif). The 3rd step is to proof that image with the CMYK
profile. A 3rd image pops up (RGB, 1 Layer)... That's Not a on the fly
preview at all.

Please, I'm sorry for my sad english, and I hope this all doesn't sounds to
rude. I wanted only spend some Information of an user point of view, that's
all...

regards

Gerhard

[1] http://www.eci.org/eci/en/044_working_colour_spaces.php

More information about the European Color Initiative and their work on
standardisation of a color workflow:

http://www.eci.org/eci/en/021_goals.php
http://www.eci.org/eci/en/035_digital_photography.php
http://www.eci.org/eci/en/050_news.php

Here is some Information for download:

http://www.eci.org/eci/downloads/ECI-en/eci_general_downloads/eci_whitepaper_1_1_ENG.pdf

46 page (~ 500 kB) 

Guidelines for device-independent color data processing in accordance with
the ICC-Standard

(Preview) Table of Content:
 
Foreword  
1. Objectives of the »European Color Initiative«  
2. Objectives and Contents of the ECI-Guidelines  
3. Commitment to Supporting the ICC-Standard 
4. Establishing the Proof  
 4.1 »Idealized ICC-Proof«  
 4.2 »ICC-Proof« (»ICC Contract Proof«)  
 4.3 »ICC-Proof with Generic Profiles« (»ICC Contract Proof«)  
 4.4 »ICC-Soft Proof« 4.5 Proprietary Digital Proof Methods  
5. Administrative Communication between »Data Supplier« and »Data Receiver«  
6. Basic Workflow for Digital Processing of Printed Material  
7. Technical Specifications for the Exchange of Advertisement Files  
 7.1 Exchange Format  
 7.2 Exchange Color Spaces  
 7.3 Overprinting and Trapping  
 7.4 Process and Data Control  
 7.5 Proofs   
 7.6 Data Exchange Media  
8. Technical Specifications for the Exchange of Files for Catalogue
Production  
 8.1 to 8.x  
9. Technical Specifications  
 9.1 to 9.x  
Appendix 1: Recommendations for the Adaptaion of ICC-Workflows in
Advertising Production  
Appendix 2: Recommendations for the Adaptation of ICC-Workflows in Catalogue
Production  
Appendix 3: Recommendations for the Adaptation of ICC-Workflows in General
Offset Production  
Appendix 4: Recommendations for the Adaptation of ICC-Workflows in Editorial
and Publishing Techniques  
Appendix 5: Process Control  The Ugra/FOGRA Media Wedge   
Appendix 6: »MediaStandardPrint« (not included)  
Appendix 7: The Corner Points of the ICC-Standard  
Appendix 8: »The 10 Commandments of Color Managements«  
Appendix 9: Example of a Measuring File in Accordance with the Color Chart
ISO 12642 (IT8.7-3) 


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Re: [Gimp-developer] Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Alastair M. Robinson
Hi Gerhard,
Gerhard Gaußling wrote:
What kind of softproof is available? Hmm.. I can nothing similar find here. 
It took me a while to find it too - it's under the View - Display Filters.
In the resulting dialog you can choose from a number of filters, 
including Colour Proof.

When we were discussing colour management a few months back, I hacked 
the Colour Proof filter to do a normal working-profile - 
monitor-profile transform, and it worked pretty well.

The sticking point with the display filters is that there's currently no 
way of getting a reference to the current image into them.  Without 
that, using a specific profile for individual images is next to 
impossible, and while we're restricted to 8-bit precision internally, 
that's pretty much a vital capability.

All the best,
--
Alastair M. Robinson
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[Gimp-developer] Re: Re: Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Gerhard Gaußling
Hal V. Engel wrote:

snip
 For those that are new to color management and would like to understand
 this better from a CM users perspective I would like to recommend that
 a good starting point is

http://www.normankoren.com/color_management_2.html#Implementation%3C/A%3EHere,
 %20you%20helped%20me,
 %20again!%20%20I%20am%20learning%20how%20to%20do%20the 

Hello Hal, thanks for the link! This is a shorter one of the same site ;-)
http://www.normankoren.com/color_management.html
or the same uri like you used in a more shorter way:
http://Implementing-cms.notlong.com

 This web site 
 is from a color management users perspective and it starts out with a
 basic overview of how color management works and what all of the
 pieces are and how they all work together.  He give examples of how to
 setup things in both Photoshop and Picture Window Pro.  So this has
 lots of info about how two different apps have set up the user
 interface for this.
 
 Also one of the interesting things on this site is that he has the
 GretagMacbeth ColorChecker test pattern in both SMPTE-240M (same as
 AdobeRGB 1998) and sRGB color spaces.  One of the patches (out of 24)
 is out of gamut in the sRGB version of the image but is in gamut in
 the SMPTE-240M image.
 

good night

Gerhard

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Re: [Gimp-developer] Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Sven Neumann
Hi,

Gerhard Gauling [EMAIL PROTECTED] writes:

 What kind of softproof is available? Hmm.. I can nothing similar find here. 

Go to View-Display Filters and enable the Display Proof filter.

 Please, I'm sorry for my sad english, and I hope this all doesn't
 sounds to rude. I wanted only spend some Information of an user
 point of view, that's all...

Your feedback is very much appreciated.


Sven
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[Gimp-developer] Re: Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Gerhard Gaußling
Sven Neumann wrote:

 Go to View-Display Filters and enable the Display Proof filter.

Thanks to you and Alastair to pointing that out, I'm quite impressed! Even
the rendering intends are there! So I'm pleased that there is some work
going on in this direction. In the GEGL TODO there is shown 0% progress for
the color models and cms, that might be not related to reality! (even if
this display filter is not part of GEGL)

 Please, I'm sorry for my sad english, and I hope this all doesn't
 sounds to rude. I wanted only spend some Information of an user
 point of view, that's all...
 
 Your feedback is very much appreciated.

You're welcome! (Hope this english fits!)

Kind regards

Gerhard

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Re: [Gimp-developer] Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Sven Neumann
Hi,

Alastair M. Robinson [EMAIL PROTECTED] writes:

 When we were discussing colour management a few months back, I
 hacked the Colour Proof filter to do a normal working-profile -
 monitor-profile transform, and it worked pretty well.

Yes, it's a shame that you never submitted this for inclusion. It
could have become part of the 2.2 release.

 The sticking point with the display filters is that there's
 currently no way of getting a reference to the current image into
 them.  Without that, using a specific profile for individual images
 is next to impossible, and while we're restricted to 8-bit precision
 internally, that's pretty much a vital capability.

Let's try to implement this in small steps then. As a first step I
would like to add a couple of options to the preferences to allow
users to define default locations for color profiles, to
enable/disable color management and to set a number of default
settings. Stefan Dhla sent me a patch last year that implements this
and I will probably base the changes on that. The settings he
suggested are:

 - use CM or not
 - display profile
 - default workspace profile
 - default rendering intent for color conversion
   + from workspace to display (default set in display profile)
   + from workspace to printer (should default to
   * perceptual for pictures
   * relative colorimetric for most other work)
 - default cmyk-profile (is later used to convert RGB-CMYK)
 - default profile path (/usr/share/color/icc/ and ~/.color/icc/)

As soon as we have such settings, we need to figure out a way to make
them available to plug-ins and modules. We also need an API to access
the color-profile attached to an image.


Sven
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Re: [Gimp-developer] Color Management was GEGL development/gimp integration

2005-01-15 Thread Gerhard Gaußling
Am Samstag 15 Januar 2005 23:42 schrieb Gerhard Gaußling:
 Photoshop lets pop up a dialog where the user can decide the kind of
 conversion he will do for the pasted/dragged image

Of course only if the source color space of the imported 
(pasted/dragged) image is different from the working color space. As I 
mentioned before the working color space is also meant as 'device 
independent' like recommended by eci.org, and there for suitable for 
archives. (The recommendations might be different for the US and other 
non-european states: there it might be recommend to use AdobeRGB as 
wotrking color space - and WebCoatedSWOPv2v as printing profile ).

If the archived files are saved in (the recommended wide working color 
space such as eciRGB or AdobeRGB, or WideGammut) the appropriate color 
space, then it can be imported without flaws (w.o. popup window with 
the selection dialog) into theGIMP.
 
regards

Gerhard

 
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[Gimp-developer] Re: Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Gerhard Gaußling
Hello Sven,

Sven Neumann wrote:

 - display profile
should be adjusted _once_ systemwide (every time changeable by systemwide
color preferences independant from the GIMP, as used by (e.g.)scribus [1],
inkscape [2], sodipodi[3] wine e.g. for Photoshop and maaybeee by
commercial apps available for *nix like Page Stream [4], Cenon [5], Viva
Designer [6]) with an monitor profile (like the one of l-prof or
adobe-gamma etc.), there for it would be a little overwhelming to have this
choice again in the opening file dialog, if the profile doesn't fits the
working color space.

regards

Gerhard

[1] http://www.scribus.org.uk/
[2] http://www.inkscape.org
[3] http://www.sodipodi.com/
[4] http://www.grasshopperllc.com/
[5] http://www.cenon.info/frame_gb.html
[6] http://www.vivaip.de/

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[Gimp-developer] Re: Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Gerhard Gaußling
Sven Neumann wrote:

 Stefan Döhla sent me a patch last year that implements this
 and I will probably base the changes on that. The settings he
 suggested are:
 
 - use CM or not
 - display profile
 - default workspace profile
 - default rendering intent for color conversion
 + from workspace to display (default set in display profile)

monitor/display profile

 + from workspace to printer (should default to

us: webcoatedSWOP for ads (coated paper) and europe: isocoated.icc (also
coated paper)

 * perceptual for pictures
 * relative colorimetric for most other work)

agreed, but flexible enough to set it to saturation or absolute rendering
intend.

 - default cmyk-profile (is later used to convert RGB-CMYK)

see above europe: isocoated.icc

 - default profile path (/usr/share/color/icc/ and ~/.color/icc/)

agreed

 As soon as we have such settings, we need to figure out a way to make
 them available to plug-ins and modules. We also need an API to access
 the color-profile attached to an image.

I like the idea of an abstract API, which can be managed by different cmm
e.g. lcms or argyll 

This seems to be all over viewed a reasonable practice to use CMS on image
manipulation.

regards

Gerhard  

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[Gimp-developer] Re: Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Gerhard Gaußling
Gerhard Gaußling wrote:

 + from workspace to printer (should default to
 
 us: webcoatedSWOP for ads (coated paper) and europe: isocoated.icc (also
 coated paper)

Only as a suggestion, please keep it flexible!

 
 * perceptual for pictures
 * relative colorimetric for most other work)
 
 agreed, but flexible enough to set it to saturation or absolute rendering
 intend.
 
 - default cmyk-profile (is later used to convert RGB-CMYK)
 
 see above europe: isocoated.icc

see above, keep it flexible! You have to have the access to choose the
printer profile of the device, which is used actually !


regards

Gerhard

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Re: [Gimp-developer] Re: Color Management was GEGL development/gimp integration

2005-01-15 Thread Hal V. Engel
On Saturday 15 January 2005 17:37, Sven Neumann wrote:
snip
 Let's try to implement this in small steps then. As a first step I
 would like to add a couple of options to the preferences to allow
 users to define default locations for color profiles, to
 enable/disable color management and to set a number of default
 settings. Stefan Dhla sent me a patch last year that implements this
 and I will probably base the changes on that. The settings he
 suggested are:
 
  - use CM or not
  - display profile
  - default workspace profile
  - default rendering intent for color conversion
+ from workspace to display (default set in display profile)
+ from workspace to printer (should default to
* perceptual for pictures
* relative colorimetric for most other work)
  - default cmyk-profile (is later used to convert RGB-CMYK)

I guess that this is for the printer?  Since all of my printers are 
logically RGB devices (the drivers expect RGB input) I am not sure how 
useful this is to me but for others it might have it's uses.  But 
perhaps we need to understand what this will be used for before 
including it.  

Also printer profiles are very specific to the printer hardware (not 
just the printer model but the specific printer you are using), the 
paper, ink and all of the driver setting (resolution, dither).  So 
I have more than one printer profile for each printer (typically 5 or 
6).  

When you are in the printer dialog in GIMP you have the ability to add 
a new logical printer and use that to name a collection of settings 
you wish to remember for future use.  This is the ideal place for 
printer profiles to be specified.  So the user should be able to set 
the default profile and rendering intents for each logical printer 
along with all of the other settings for the driver.  This would be a 
way better setup than how this is handled in photoshop and would be a 
great way to simplify and facilitate the management this part of a CM 
work flow.

  - default profile path (/usr/share/color/icc/ and ~/.color/icc/)

All of the other stuff looks fine to me. 

-- 
Hal V. Engel


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