gThumb red eye reduction does not work

[markba]

Binary package hint: gthumb

When trying to make a selection in the 'Red-eye removal', I was not able to make a selection.
I recall that this functionallity once worked after added, somewhere in the Feisty update cycle.

Feisty, gThumb 2.9.1

Changed description (see my comment below):
- red eye removal does not work anymore
- label 'Selection' should be 'Position' so it is celar for the user the he isn't supposed to make a selection but just click
Also changed the summary.

[mjc (mjc-avtechpulse)]

You don't make "selections" in the red-eye removal tool. You just click on the red eye. Is that the problem? If not, please clarify.

- Mike

[markba (mark-baaijens)]

After examining this behaviour again (as you pointed out) I can not make a selection. I *thought* I should make a selection, because the label on the right upper side says 'Selection'. As it turns out, this is a position and not a selection (should have 4 points and not just 2).

Next, I just clicked in an red eye area and nothing happened.

Guess my problem is two sided:
- red eye removal does not work at all (at least, it seems to in my case)
- label 'Selection' should be 'Position' to prevent user errors (not critical)

As I mentioned before, I recall this functionality has been working before.

Changed the original description.

[mjc (mjc-avtechpulse)]

Thanks for the clarification.

1) I have changed "Selection" to "Position" in trunk.

2) If no red eye is found, nothing happens. (Maybe we should have a warning message.) Perhaps the algorithm just isn't working in your particular photo. Can you test on a couple of red eyes? The algorithm does not work well on "orange eyes" or "white eyes", which seem common with young children.

- Mike

[markba (mark-baaijens)]

OK, tried it on the photo attached. Red eye removal does not work there. Sure, the eyes are not ezxactly red (more white) but then again, this is an effect from the flash I would like to remove. Maybe (as you suggested) the algorithm is to precise.

[mjc (mjc-avtechpulse)]

Ah, that's a very hard image to correct. gThumb can't handle it. The eyes are too small and not red enough. If you find an open-source tool that can correct those eyes automatically let me know, and maybe we'll steal their algorithm.

However, if you click on the children's sweaters, the red-sweater-removal tool seems to work :-)

- Mike

[markba (mark-baaijens)]

I tried digikam on this photo and it also did not succeed.

[markba (mark-baaijens)]

Maybe a warning (your suggestion) that gThumb does work on the selected area (point) should do the trick. Then it is clear for the user that the problem is the material on the photo it self on not the gThumb program. Maybe in the future there will be a better algorythm...

[Pedro Villavicencio (pedro)]

Would be nice if someone getting this problem can forward the bug upstream.

[sonicsteve (sonic-yfc)]

I would like to report this also. Often in pics the eyes are orange/red. The tool only works well with eyes that are clearly red. The tool needs to be configurable or needs to be made so it can remove orange/red/ or whatever to normal.
If the tool was used like a drag/selection box so you select the are of the eye this would perhaps make the selection easier. That way the program would have a defined area of space to change the colors.

[sonicsteve (sonic-yfc)]

That comment was perhaps a bit confusing. Really after using this tool I find that the algorithm simply needs to be adjusted. I have found that it will only work unless the eyes are perfectly red. If there is pink, orange, or anything other than red, it just leaves it alone and changes the red pixels and ignores everything else. More often than not the tool will only change a fraction of the eye and leave the rest orange, pink or white.
My suggestion in the previous comment is just that if you can define the area of the eye, it might make it easier for the algorithm to handle. This way it knows that the eye has a pupil, since orange or pink is not a natural eye colour it can change it to grey/black as a pupil should be.

[mjc (mjc-avtechpulse)]

The author of the redeye tool set the algorithm parameters at values that seemed to give the best results. He found that adding adjustable parameters didn't help much.

I don't like the idea of selection areas - it gets too complicated.

This is actually a really hard function to do well. However, the redeye tool is nicely isolated in src/dlg-redeye-removal.c. Please experiment with it! If you find a better method, please submit a patch upstream.

- Mike

[Daniel T Chen (crimsun)]

Is this symptom still reproducible in 8.10 alpha?

[markba (mark-baaijens)]

Checked in gThumb 9.10.9 (Ubuntu Intrepid alpha-6).
Label 'Selection' is not renamed to 'Position' as opposed to https://bugs.launchpad.net/ubuntu/+source/gthumb/+bug/85780/comments/3 (comment #1).

[markba (mark-baaijens)]

Version is 2.10.9, not 9.10.9.

[Pedro Villavicencio (pedro)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. You reported this bug a while ago and there hasn't been any activity in it recently. We were wondering is this still an issue for you? Thanks in advance.

[Pedro Villavicencio (pedro)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to New. Thanks again!.