Fixing light leaks (a LOT of them) with Gimp

[alexander750]

First off, hello everyone!

I've been reading the forums to try to get a handle on how to fix light leak damage, especially if the fix could be automated somehow. I have about 250 such photos.

The damage consists of two different types, illustrated by the attached examples. Many photos are affected by both types to varying degrees; the camera I was using (a Canon AE-1) had a worn, crumbling back seal.

Also, I'm using the latest version of Gimp (2.6.4 as of this writing) for Mac, and an older version (2.4) for Linux. I do not have Photoshop; while I believe the techniques would be the same, the actual procedure will be different.

I get about as far as "create a layer mask from the duplicate background layer, and fill with gradient" before running into trouble. How do I build a gradient of the proper shape and intensity (or intensities--while the damage I've indicated in the first example below is most apparent in the red channel, all three channels are affected in many cases) to use in the mask?

[igot2pman]

Well for the white ones, you can use exposure adj in a new layer with the offset and gama all the way down and set to softlight blending mode.

This is in PS, but there should be something in gimp. This should bring back most of it except the really bad.

In the below picture I used 4 expousure layers set to soft light with the affected masked and 1 exposure layer set to normal. and lastly a masked color correction (had a blue tint) to finnish it off.

Hope this helps,
-Keven

[igot2pman]

The bridge one can be fixed quite easily with curves. Just select the grey dropper tool and click the grey bridge. Then mask only the affected parts, if it only needs half the correction then only mask it half and so on. You can save the curves correction and then apply it to all your other pictures.

You can also use color balance and add more cyan then mask the affected.

Unfortunately the leak also killed your sky. There is no saving it so you have to replace or just white the whole thing out.

Sorry about not helping in gimp, I just do not use it.

Hope this helps,
-Keven

[alexander750]

I believe I get it now...

Working inwards, from the least to the most damaged areas, and using the broadest possible feathering with the selection tools (for the Gimp, that's 100 pixels), I'd use the curves, color balance, etc., to pull the outermost parts of the selected area into balance. After making the adjustment, deselect everything; if there's a noticeable boundary, I've overcorrected--undo and try again.

As I work inward, save each selection, with its (successful) adjustments, as a mask layer. Eventually, all these mask/adjustment layers will form a "filter stack" which can be collected into a separate file for reuse.

Below is a screenshot of Gimp in action, with the second example above.

Thank you for your help--and the personal attention! I know, judging from the results of a forum search, you get this same question all the time...

[igot2pman]

lOl, Yes I have answered this question a few times. But each one is slightly different. And I try to Learn something new with every help. Like this time the normal exposure correct was just to black, switching it to soft light blending mode (never done b4) preserved the colors better. Learned something new.

You did a good job from what I can see. I tried GIMP a long time ago but for me I was to used to PS. Good job explaining it in GIMP, might help someone in the future.

Well, good luck with the rest of them. If you need any more help I am always here. And if I can't help, someone here surely can.

-Keven

[Kraellin]

i seem to recall a similar thread where Flora answered and did a superb fix of the problem. i'm sorry, i dont recall what this thread was named or even how old it is now, but maybe a search will turn it up for you. it is in this forum.

[BabyKangaroo]

Originally Posted by igot2pman

The bridge one can be fixed quite easily with curves. Just select the grey dropper tool and click the grey bridge. Then mask only the affected parts, if it only needs half the correction then only mask it half and so on. You can save the curves correction and then apply it to all your other pictures.

You can also use color balance and add more cyan then mask the affected.

Unfortunately the leak also killed your sky. There is no saving it so you have to replace or just white the whole thing out.

Sorry about not helping in gimp, I just do not use it.

Hope this helps,
-Keven

_______________________________________________________________


hey i know this is from last year but was hoping you could tell me how to remove the light purple splodges and white dots from this picture?


http://i532.photobucket.com/albums/e...achWales06.jpg

[igot2pman]

Originally Posted by BabyKangaroo

how to remove the light purple splodges and white dots from this picture?

Easiest way would just to paint over it in a new layer in color blending mode. Just sample near by.


Below is just another way:

1. Use color range to select the purple use the plus dropper till you get it all
2. Then create a color balance adjustment layer
3. the mask should already be made with the selection from color range. but if its not, fill with black and paint with white over the bad areas.
4. Start with midtones and move the blue-yellow over to the left (yellow side). Keep adjusting till you get it to where you like it.

If you need to go further, you can paint over it in color blending mode

As for the white dots, just use the heal or clone tool as they are small.

Hope it helps,
-Keven

Next time start your own thread and more people can help and try their hand at it. but as your new i will let it slide. Welcome to RTP.

Below is what came up with:

[BabyKangaroo]

Kevin

Thanks That worked Perfect =]

[unimatrix001]

i followed this tutorial i found here http://retouchpro.com/tutorials/?m=show&id=304 not sure if this works for gimp havent used it much but it works pretty good with photoshop. the only thing i did different was replace the sky rather the use a selective color to fix it.