How to darken / heal bright spots while retaining texture

[tommik128]

I struggle to find the proper way of darkening or healing the spots on a scanned image. I have tried using Colors - Levels and also Filters - Enhance - Heal Selection. But the results are not convincing. I either get improper brightness in comparison to surroundings or the texture in those spots is kinda blurred / damaged. I would like to retain the source texture just have the spots to get darker so that they match the surroundings.

Thanks you for your time.

 

[denzjos]

Try colours/levels or color curves :
   
   

[Blighty]

Create a duplicate layer on work on that. If you don't like your edits just delete the layer and start again.

Select a suitable ForeGround colour (eg 20,20,40). (Experiment with different values to get the effect you want.)

Select a brush and set the brush Mode to Darken Only. Paint over the bright spots.
(Alternative: create a transparent layer above and set the layer mode to Darken Only)

(Use Undo and try again.)

[denzjos]

If you don't get rid of the white spots, you can use Filters / GMic-Qt / Repair / Pixel Denoise before you use levels or/and curves

   

[akovia]

You might try using a Descreen filter which is designed to deal with those spots specifically.

Here are some different examples.

   

The first Descreen is an old gimp script I've attached.

The gmic filters should be self explanatory. Use Remove Hot Pixels first, then Descreen. 

You could then process the image further by sharpening and levels if you wish.


  descreen.scm.zip (Size: 1.5 KB / Downloads: 255)

[tommik128]

Well, I must say this is quite complex task for me. But I managed to sort of heal the bright areas by using 2 approaches: Clone Tool in Darken Only mode with some Opacity down + Fuzzy Select Tool and playing with Colors - Curves. Definitely trial and error thing for me...

The brush method did not work for me since it was rather repainting the whole texture. Also the filters seem to redraw the texture + I do not have the Pixel Denoise among GMic anyway for some reason.

Thanks.

[denzjos]

It is always difficult to find a solution if only a part of a picture (I think) is posted because one can not see how the rest of the picture responds on a try. If it's possible post the whole picture or a part of it with some useful information on it.

[tommik128]

(11-25-2019, 09:02 AM)denzjos Wrote: It is always difficult to find a solution if only a part of a picture (I think) is posted because one can not see how the rest of the picture responds on a try. If it's possible post the whole picture or a part of it with some useful information on it.

It is the cover of the album The Best Of Testament I downloaded years ago. Hope it is not illegal to post it here...

Here is the source cover:

https://i.imgur.com/7oAwYCj.jpg

And here is my attempt:

https://i.imgur.com/W4tF4Y8.jpg

[akovia]

There are some good tips here for scanning, but also processing after the fact.

You did a nice job with cleaning the edges and healing some areas, but I would really run g'mic's descreen on this as you can still clearly see the scan dots.

[denzjos]

try this : 
open the picture
copy the layer
blur 2 to the copy layer 
copy the blurred layer (layer 2) 
on layer 2 : filters / enhance / high pass (if not, reset to standard values :  4.0 / 1.000)
on layer 2 : colours / brightness-contrast (set contrast 15 / brightness 0)
on layer 2 : set layer mode to linear light 
in needed, use filters / enhance / sharpen (unsharp mask)
-------------------------------
An easy way to get rid of the white points, use Qmic Qt :

Artistic / Kuwahara (Iritations 2 / Radius 2)
or
Artistic / Sharp Abstract (Spatial scale 2.4)
or
Repair / Recursive Median (Median radius 4 / Repeats 2)
or
Repair / Remove hot pixels (Mask size 4 / Threshold 10)