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+--- Thread: Make a scan document look flat (remove shadows) (/Thread-Make-a-scan-document-look-flat-remove-shadows)
Make a scan document look flat (remove shadows) - Pyrrhon - 08-25-2020
Hello!
I am new here and need some help!
So my wife made some tea dyied paper that I scanned... Problem is that because of the fluids the paper is not flat anymore.
You can clearly see it on the scan (shadows)
Now I tried a lot of youtube tutorials but it never fit my situation.
Does someone have a tip for me? A solution?
I would appreciate it very much!
EDIT: here is part of the picture attached
Best,
Pyrrhon
RE: Make a scan document look flat (remove shadows) - rich2005 - 08-25-2020
You image has not come through.
Perhaps it is too large for the forum. Can you post it to some storage such as dropbox and post the link here.
RE: Make a scan document look flat (remove shadows) - Pyrrhon - 08-25-2020
Hi,
I think it fits now, I updated the thread and attached the picture (206Kb)
RE: Make a scan document look flat (remove shadows) - Ofnuts - 08-25-2020
One solution with Gimp 2.10:
* Filters>Enhance>Wavelet decompose and decompose to maximum level (7).
* In the 'Residual' layer, sample the color (sample average with a marge radius)
* Bucket-fill the layer with the sample color (so tha it becomes a uniform layer)
[attachment=4794]
A "softer" but a bit more labor-intensive version is to paint the problem areas of the Residual layer with a large and soft brush.
A more perfect version would also do something similar on the nect to last layer (level 7).
A completely different solution is to do two scans after rotating the paper by 180° in between. Then in Gimp you align the two images and set the top one to "Lighten only". Caveat: this requires an accurate scanner, the scanners of combined printer-scanners are rarely accurate enough.
RE: Make a scan document look flat (remove shadows) - Pyrrhon - 08-25-2020
Thanks for the thourough answer! I will let you know what worked.
Best
jb
One solution with Gimp 2.10:
* Filters>Enhance>Wavelet decompose and decompose to maximum level (7).
* In the 'Residual' layer, sample the color (sample average with a marge radius)
* Bucket-fill the layer with the sample color (so tha it becomes a uniform layer)
A "softer" but a bit more labor-intensive version is to paint the problem areas of the Residual layer with a large and soft brush.
A more perfect version would also do something similar on the nect to last layer (level 7).
A completely different solution is to do two scans after rotating the paper by 180° in between. Then in Gimp you align the two images and set the top one to "Lighten only". Caveat: this requires an accurate scanner, the scanners of combined printer-scanners are rarely accurate enough.
RE: Make a scan document look flat (remove shadows) - Pyrrhon - 08-27-2020
Hi,
Wavelet Decompose seems to be a good option, I am going further into it with tutorials!
Thank you so much,
best
pyrrhon