techniques for removing fringing?

Discussion in 'Digital Photography' started by Colin Brace, Apr 6, 2006.

  1. Colin Brace

    Colin Brace Guest

    Hi all,

    I am wondering if anyone can suggest a way of removing fringing from an
    image. I shot this picture, <http://lim.nl/dockworker%2020060403.jpg>,
    with the sun behind me, yet it was a very hazy day and I see notable
    cyan and purple fringing on the left and right sides resp. of the
    statute against the sky. Although I use gimp, photoshop techniques are
    welcome, as I can probably emulate them in the former.

    Thanks.

    --
    Colin Brace
    Amsterdam
    Colin Brace, Apr 6, 2006
    #1
    1. Advertising

  2. Colin Brace wrote:
    > Hi all,
    >
    > I am wondering if anyone can suggest a way of removing fringing from
    > an image. I shot this picture,
    > <http://lim.nl/dockworker%2020060403.jpg>, with the sun behind me,
    > yet it was a very hazy day and I see notable cyan and purple fringing
    > on the left and right sides resp. of the statute against the sky.
    > Although I use gimp, photoshop techniques are welcome, as I can
    > probably emulate them in the former.
    >
    > Thanks.


    Paint Shop Pro has an effective "CA Reduction" function built in.

    Works for PF as well as CA.

    David
    David J Taylor, Apr 6, 2006
    #2
    1. Advertising

  3. Colin Brace

    Paul Heslop Guest

    Colin Brace wrote:
    >
    > Hi all,
    >
    > I am wondering if anyone can suggest a way of removing fringing from an
    > image. I shot this picture, <http://lim.nl/dockworker%2020060403.jpg>,
    > with the sun behind me, yet it was a very hazy day and I see notable
    > cyan and purple fringing on the left and right sides resp. of the
    > statute against the sky. Although I use gimp, photoshop techniques are
    > welcome, as I can probably emulate them in the former.
    >
    > Thanks.
    >
    > --
    > Colin Brace
    > Amsterdam


    I can never get the prest Paintshop thing to work, but some time ago I
    found this method and this works for sure. Remember though to watch
    how you use the saturation slider, as although they look identical
    sometimes the fringing is a slightly different hue so it's worth
    trying different setting for different pics. This is exactly as i
    copied and pasted from somewhere on the web :O)
    ------------------------------------------------------

    a faster and better way — the Hue/Saturation/Lightness (HSL) tool. For
    details see the May 2003 Graphics column (available online here),
    which covered some of the hidden tricks of this under-used feature.

    Instructions for using HSL to remove purple fringing will vary
    slightly between programs, but they all follow the same basic process.
    Start by loading up your affected image. Now go to the HSL tool. In
    Photoshop, select Image-Adjustments-Hue/Saturation… In Photoshop
    Elements 2, select Enhance-Adjust Color-Hue Saturation… and in Paint
    Shop Pro 8 Adjust-Hue & Saturation-Hue/Saturation/Lightness.

    Here is the important step: click the blue channel. Do not adjust the
    master channel. Now adjust the saturation slider to around 80 per cent
    (you can fine-tune this later).

    If you are using Paint Shop Pro 8, move the colour wheel slowly around
    and watch the preview window. When you hit the right spot, the purple
    will vanish. Fine-tune the slider for maximum effect and click OK. If
    there are still traces of purple, repeat the process until you find
    the other tone.

    The Adobe products take guesswork out of the HSL adjustment step. When
    the blue channel is selected, the eye dropper tool will become
    available. Click the eyedropper on the left and use it to sample the
    purple fringe in your image. You can use the colour slider at the
    bottom to make finer adjustments (tip: you can also use the + and -
    keys to zoom in and out of the image while the HSL window is still
    open).

    Finally, you may find the image needs some minor tinkering and will
    probably appear a little washed out. Making fine adjustments to the
    Brightness/Contrast or Levels settings will correct these problems
    ---------------------------------------------

    --
    Paul (Everyone I know goes away in the end)
    -------------------------------------------------------
    Stop and Look
    http://www.geocities.com/dreamst8me/
    Paul Heslop, Apr 6, 2006
    #3
  4. Colin Brace <> wrote:
    > with the sun behind me, yet it was a very hazy day and I see notable
    > cyan and purple fringing


    I'm wondering: why cyan and purple? They're not complementary
    colors or anything...something to do with the properties of the sensor?
    I know about chromatic aberration, which would seem to explain purple,
    but I don't get cyan.

    --
    Oh to have a lodge in some vast wilderness. Where rumors of oppression
    and deceit, of unsuccessful and successful wars may never reach me
    anymore.
    -- William Cowper
    Jeremiah DeWitt Weiner, Apr 6, 2006
    #4
  5. Colin Brace

    Colin Brace Guest

    > I'm wondering: why cyan and purple? They're not complementary
    > colors or anything...something to do with the properties of the sensor?
    > I know about chromatic aberration, which would seem to explain purple,
    > but I don't get cyan.


    Ah, maybe cyan isn't quite the right way to describe. Here is a section
    of the image magnifed 550x: http://lim.nl/Screenshot-dsc01421-550x.jpg

    See what I mean? I am not quite sure what to call this color; maybe a
    shade of aquamarine or something?

    In any case, I am going to try the technique mentioned by Paul Heslop
    above.

    --
    Colin Brace
    Amsterdam
    Colin Brace, Apr 7, 2006
    #5
  6. Colin Brace <> wrote:
    > See what I mean? I am not quite sure what to call this color; maybe a
    > shade of aquamarine or something?


    No, I completely see what you're talking about - it's a kind of
    blue-green - I just don't understand why that particular color would be
    showing up in fringing. My curiosity is purely academic, anyway. :^)


    --
    Oh to have a lodge in some vast wilderness. Where rumors of oppression
    and deceit, of unsuccessful and successful wars may never reach me
    anymore.
    -- William Cowper
    Jeremiah DeWitt Weiner, Apr 7, 2006
    #6
  7. Colin Brace

    J. Clarke Guest

    Jeremiah DeWitt Weiner wrote:

    > Colin Brace <> wrote:
    >> See what I mean? I am not quite sure what to call this color; maybe a
    >> shade of aquamarine or something?

    >
    > No, I completely see what you're talking about - it's a kind of
    > blue-green - I just don't understand why that particular color would be
    > showing up in fringing. My curiosity is purely academic, anyway. :^)


    Where is that area located in relation to the center of the frame? If you
    look equidistant in the other direction do you see the same fringing but
    reversed? If you still have access to the location and similar lighting
    conditions can you try the same shot with the camera inverted and see if
    you get the same effect in the same place on the inverted frame?

    You said it was a very hazy day--could that be simply a partial rainbow due
    to the haze?

    If it was being displayed on a CRT or 3 CCD projector I'd say that it looked
    like a convergence problem--leads me to wonder if it could be simply an
    artifact of the arrangement of pixels on the sensor.

    --
    --John
    to email, dial "usenet" and validate
    (was jclarke at eye bee em dot net)
    J. Clarke, May 12, 2006
    #7
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Richard Dock

    What's with the obession with "Purple Fringing"?

    Richard Dock, Jul 22, 2003, in forum: Digital Photography
    Replies:
    23
    Views:
    841
    John Navas
    Jul 24, 2003
  2. Miro

    Re: Canon S50 blue fringing

    Miro, Aug 6, 2003, in forum: Digital Photography
    Replies:
    6
    Views:
    346
  3. Lucas

    Canon G5 i "purple fringing"...

    Lucas, Sep 25, 2003, in forum: Digital Photography
    Replies:
    2
    Views:
    491
    Lucas
    Sep 25, 2003
  4. Mike Engles

    Sigma SD10 Fringing

    Mike Engles, Oct 29, 2003, in forum: Digital Photography
    Replies:
    54
    Views:
    1,261
    Guest
    Nov 5, 2003
  5. Giuen
    Replies:
    0
    Views:
    751
    Giuen
    Sep 12, 2008
Loading...

Share This Page