GNOME Bugzilla – Bug 564697
Recomposing 'YCbCrITU R470 256' and 'YCbCrITU R709 256' causes 'Error scanning 'decompose-data' parasite: too few layers found'
Last modified: 2015-04-14 18:13:43 UTC
Steps to reproduce: 1. Load an image with alpha channel 2. Colors->Components->Decompose (Alpha) from the image (that is, in the Decompose dialog, select Alpha). It doesn't matter whether 'Decompose to layers' is checked or not. 3. Edit the resulting image 4. Colors->Components->Recompose Actual Result: Error message pops up: "Error scanning 'decompose-data' parasite: too few layers found" Expected Result: Alpha channel is recomposed into source image.
The same happens in GIMP 2.6.3.
I've been looking around and I think that this is more a feature implementation than a bug. The compose plug-in doesn't support composing from less than 3 sources and also doesn't create an alpha layer if it doesn't exist. I could implement it but it would need a fair amount of code. Is it worth it to do?
Recompose is not meant to merge components into existing layers, it only creates new ones.
*** Bug 689477 has been marked as a duplicate of this bug. ***
Confirming for GIMP 2.8.2 on Mac OS X and Windows.
*** Bug 747853 has been marked as a duplicate of this bug. ***
The reporter of duplicate bug 747853 tracked it down to incorrect strings in decompose.c
Changed the subject because recomposing of individual components is (naturally) not supported and should probably give another error message.
Fixed in gimp-2-8, in master, the bug was fixed by a refactoring. commit df7969c08d531c1c310c85d132b30321e838a47e Author: Michael Natterer <mitch@gimp.org> Date: Tue Apr 14 20:08:17 2015 +0200 Bug 564697 - Recomposing 'YCbCrITU R470 256' and 'YCbCrITU R709 256'... ...causes 'Error scanning 'decompose-data' parasite: too few layers found' Fix the identifier strings of the color models to have underscores instead of spaces. Found by Jonathan Tait. plug-ins/common/decompose.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)