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Thread: Photo repair showcase - removing paper texture and scratches

  1. #1
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    Default Photo repair showcase - removing paper texture and scratches

    When scanning a photo printed on textured paper, the texture will show up in the scanned image which is very difficult to remove, as seen in the following image:



    If the texture is a fixed pattern type like the above picture, then there is a useful technique I recently discovered that can reduce the appearance of the texture. This technique does not ivolve using noise reduction software such as Neat Image or using blurring, and there is actually some gain in details as compared with using noise reduction software.

    Here's the repaired photo using this technique, with additional processing with the healing brush to repair the scratches:



    What do you think of the result of this technique? And can you guess how it was done?

    - Roy
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

  2. #2

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    Hmmm.....did you scan the photo twice?

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    Quote Originally Posted by jopel
    Hmmm.....did you scan the photo twice?
    Yes!
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

  4. #4

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    Quote Originally Posted by jopel
    Hmmm.....did you scan the photo twice?
    Sorry but what do you mean by scan the pic twice? Care to explain?

    Thanks.

  5. #5

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    after you scan the first round, rotate the photo (abt 3-5degree) and scan again.
    in PS align the images.

    no easy task tough. a bit of trial and error for me.

  6. #6

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    Why not just use band-pass filter on the frequency spectrum of the image? isn't that easier?

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    Quote Originally Posted by jopel
    after you scan the first round, rotate the photo (abt 3-5degree) and scan again.
    in PS align the images.

    no easy task tough. a bit of trial and error for me.
    Actually the photo is rotated 180 degrees for the second scan. That way the intensity variances caused by the texture is reversed on the second scan and so they cancel each other pretty well when the 2 scans are overlapped.
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

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    Quote Originally Posted by AReality
    Why not just use band-pass filter on the frequency spectrum of the image? isn't that easier?
    I have not tried that...but my guess is, since the frequency of the texture is in the same range as some parts of the image itself, such filtering will likely result in loss of details.

    Thanks for the suggestion and I will try that later.
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

  9. #9

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    Quote Originally Posted by roygoh
    What do you think of the result of this technique? And can you guess how it was done?

    - Roy
    Wah, like exam question!

    Thanks for the sharing and the lesson :-)

  10. #10
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    did scanning it twice reduce the paper tear? mmm how did it do that?

    paper texture i can understand.. but paper tear?

    so if i scanned it 4 times at 90degrees apart can i remove even more texture pattern?
    “How fortunate for leaders that men do not think.” - Adolf Hitler

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    Quote Originally Posted by yanyewkay
    did scanning it twice reduce the paper tear? mmm how did it do that?

    paper texture i can understand.. but paper tear?

    so if i scanned it 4 times at 90degrees apart can i remove even more texture pattern?
    Haha...no lah..the tear marks were removed by the healing brush. Very labour intensive versus using the dust and scratch removal function, but the results are much better.

    If the photo has been folded, I believe scanning in 2 directions and stacking the scans would help to reduce the creases also.

    If the paper texture is random pattern, then scanning in all 4 directions will probably help better in reducing the texture pattern in the scanned image.

    This is the same effect as diffused flash photography. The LED light source souce of my flatbed scanner is located on one side of the CCD sensor strip, so it brings out the texture in the form of uneven illumination. scanning in opposite directions and blending the scans is equivalent to having a scanner with LEDs on both sides of the CCD sensor strip.
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

  12. #12
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    good technique thanks for sharing
    “How fortunate for leaders that men do not think.” - Adolf Hitler

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