GNOME Bugzilla – Bug 490182
Histogram updating
Last modified: 2008-10-30 20:02:04 UTC
Could be enormously useful if the histogram could be updated in real time using levels and curves (and maybe other image filters), following the image preview. Better, the old histogram could be grayed in the background, the previewed black in the foreground. This is nearly mandatory retouching photos, especially using levels. Many many thanks if you could make this (and sorry for my english). Other information:
Actually, I am pretty sure that it used to do that.
This is most probably caused by this change: 2007-06-27 Michael Natterer <mitch@gimp.org> * app/core/gimpimagemap.c (gimp_image_map_clear) (gimp_image_map_do): update the image, not the drawable so we avoid constantly invalidating the drawable preview. * app/tools/gimpimagemaptool.c (gimp_image_map_tool_response): invalidate the drawable preview here.
I suggest that above change is reverted. The image-map tools should update the drawable and the histogram should be updated whenever the drawable data changes (currently it listens to invalidate-preview, which is also incorrect). In order to suppress updates of the preview, we could introduce gimp_viewable_preview_freeze() and gimp_viewable_preview_thaw().
Created attachment 97863 [details] [review] rouch outline of the proposed fix
I have committed something along those lines: 2007-10-26 Sven Neumann <sven@gimp.org> Reenabled update of the histogram while doing color corrections (bug 490182): * app/core/gimpviewable.[ch]: added new methods preview_freeze() and preview_thaw(). * app/core/gimpimagemap.c (gimp_image_map_new): freeze the drawable preview. (gimp_image_map_dispose): thaw the drawable preview. (gimp_image_map_do): update the drawable, not the image. * app/tools/gimpimagemaptool.c (gimp_image_map_tool_response): no need to invalidate the drawable preview any longer.
Is it possible to have the old histogram grayed in the background when I'm using levels (or curves or other color modifications)? Thanks!
You have the old histogram in the Levels or Curves dialog and the updating histogram in the Histogram window. That is the behavior from 2.2 which has been restored by the bug-fix. This bug is now closed and it is futile to add further comments to it.
I don't want to be spoiled or pressing, but retouching photo is useful to see old and current histograms superimposed, on the same window. Sorry, maybe I'm wrong to write this comment here. Please be patient, I'm not confident with bugzilla. Andrea
*** Bug 496441 has been marked as a duplicate of this bug. ***