View Single Post
  #4  
Old November 15th 12, 01:11 AM posted to sci.engr.color,sci.image.processing,rec.photo.darkroom,rec.photo.digital
Dale[_2_]
external usenet poster
 
Posts: 137
Default gimp and ICC color working spaces

On 11/14/2012 09:35 AM, Floyd L. Davidson wrote:
Thomas Richter wrote:
Am 14.11.2012 05:56, schrieb Dale:
gimp has 2 use cases

1) monitor proofing
2) print proofing

yet it only has RGB and CMYK choices for working spaces

I don't know if Photoshop or other software has a CIE colorimetric
choice for working space, but in order to measure and track color it
would be a lot easier to have one

I know there are issues like gamut differences and rendering intents

but if you want to measure the colorimetry of the monitor or proof and
match it to the print, you need to start with CIE, not RGB or CMYK,
ideally CIECAM but ICC has not gone there yet as far as I know


The gimp bug report and feature request list is he

https://bugzilla.gnome.org/buglist.c...t%3A%22GIMP%22


There is no bug though.

The "RGB" and "CMYK" labels are just that, labels for
two selectable workspaces that the user can easily
switch between.

But the workspace assigned to either of those two labels
can be
1) virtually anything the system administrator
has installed and made available, or
2) anything the user chooses to install privately.

Any user that wants to use a different workspace merely
needs to download whatever it is and install it. In
GIMP, select the Edit-Preferences-Color Management
menu. Both the "RGB" and "CMYK" profile options have a
selection box, and the last option in either box is to
"Select color profile from disk". Once a profile has
been selected it will then show up as one of the
available options and choosing it will not require
locating it again.

Sources for such profiles include LCMS, Argyll, and others.




you are right, my post was not a bug report, I was trying to prompt a
feature discussion

RGB aand CMYK are sensitometric and densitrometric spaces respectively,
and are linear withh with respect to light

I was suggesting a colorimetric working space like CIELAB or CIELUV
because delta E* is linear with just noticeable differences of the eye
and can be measured with a colorimeter or spectrophotometer or
spectroradiometer

--
Dale