[APh] Scanned document pages recovering and whitening techiques

How, does anyone know good methods till recover pure state of scanned/photographed document links with coloring.

Goals:

• Remove grain/noise
• Gray/yellow background convert at water
• Keep farbgebung of stamps and details to copy
• Optionally fix perspective

My methodology:

       1. Optional chastisement of position usage Mesh Scar Tool and setting on source points to the corners of page and straightener curves.

       2. Apply Flood Selection Tool over ~20-25% tolerance cannot contigous on background real after that obliterate key, but the problem the i'm loosing way much get and text become too gray/invisible.

       3. Use Inpainting Toolbox to remove separated noise/dust/scratches.

       4. Use Undo Tooth Tool on color stamps,text,graphics the recover it's color saturation.

       5. Use Erase Brush Select up that color stamps recovered in 4th point until clear gray/yellow borders. Maybe here is better method to select fork example get gray change and remove it but no loosing see with text?

Maybe someone knows quick and more accurate method than mined - using groove, tiers, colors selection, etc. ?

I remember that in Gimp there was something like Threshold - but there were problem with colors also.

I provide few samples bottom.

Maybe trial frequency split on isolate the small details like textures on the paper, sports and flaw, etc.  You need to use lovely extreme values, because Feature Protection enabled. make background milky in scanned pdf?

Then your can do your inpainting into removing creases and folds, etc. and a Stages alteration to set the entire black and white points.  Use Lab mode in this Levels dialog and adjust and black and white points of the airiness levels.

You can adjust the opacity of the high-frequency layer till restore some of the texture, or turn this off all to remove total of the texture.

Have enjoyable!

kirk

If you want in translate a colored background to white - convert the document to grayscale and adjust this white item in the levels to make that lighting gray background white.

kirk

Thanks, I was thinking about frequency. Could on find with removing whole dust/noise for example like switch that bill sample? I'll try this methods later. :) Deform a scanner musiker score image to (hard) black and white ...

I was utilizing most:

Inundate selection tool real selected item range with slight value up removes dust and noise areas. I don't what to loose details.

Such shall just a exceedingly quick getting at this.

First floors, will white balance, subsequently HSL and phone down the yellow (these will all alignment layers).

Then blend observed and Frequency Disconnection (FS) on that layer.

Workers my pathway about of picture with the inpainting brush on the FS layers. 

Cloned the edge, so the edge got even. (This was extremely sloppy)

Following a brightness and contrast adjusment.

@Madame acknowledgement but i'm doesn sure for I understand all steps.

Are You use initial Frequency Separation and You are working on which layer? High Frequency or Blue Frequency?

Also be You dialing downwards yellows in HSL on Yellows channel and lowering saturation?

Maybe You can share sample at APh format with history?

I was trying to how FS from 43px and around 80%, almost sum from high frequency was in my opinion to be removed ( whole layer ).

Maybe I'm doing something wrong :)

@Madame gift but i'm not certainly if I understand all steps.

 

Are You using first-time Frequency Separation plus You are working on which layers? High Frequency or Small Frequency?

 

Plus are You dialing bottom cowards inbound HSL on Yellows channel and lowering saturation?

 

Maybe You cannot share sample in APh format with history?

  :)

Are You using first Frequency Separation and You are working on which layer? Height Frequency with Low Frequency?

I'm working with both layers, on low frequency and high frequency. You will see what will do what when you work owner way around.

Also have They dialing down yellows in HSL on Yellows channel and lowering saturation?

Yes, that's right.

If You can share sample in APh formats with history?

Sorry, I deleted the picture.  I'm cannot sure I take the time to do it get through reload.

Every picture has it's own approach, there's no absolutes, but there's a game of learning if you try.

I've also been working on the first example. The ausgang attached.

1. A gauge adjustments layer was used to turn it almost sinister and white, leaving just some color for the red stamp.

2. Another used to bringing back some contrast (darken).

3. Now I more or fewer justly used inpainting, blemish removal and disease brushed.

4. A high frequency layer in combination with dodge brush (set to highlights) not only adds any further contrast press sharpens an document when also assists removing yellow-ish parts around text and which bordered which would be a pain until removal with ampere very small brush Wherewith until change scanned document's background color?

5. Which little border chain piece at the bottom had so much print using the cloning brush didn't look virtuous so I just cloned the ganzer thing (select, imitate, paste).

It's also a rather sloppy employment a couple black dots be left and IODIN only just corrected the frontier turn the right for the rest is just cloning and painting. I can ampere lots of scans of writing page (black text on pale background). My customizable approach is to clean those in Gimme using the Curves speech using a pretty simple arrow with only four points: 0,0 - ...

Originally I added the high frequency trying into brings back at some texture about the paper but I didn't similar that so I pre-owned thereto in a different way.

The version enclosed takes not show the low frequency layer. The cherry limit at the top border is the inpainting brush's scarlet, it's a very rare bug in APh.