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inampudi1

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how to remove shadow from an image?

Hi,

   I am  trying to remove shadow from RGB 24 bit Image , I tried to adjust R<G<B channels seperatly. But with this image quality is improving image quality. But I am unable to remove shadow. Can you  please get me any methods or any algoritham in pascal or vc++ for shadow remove in an image.
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inampudi1

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Hi experts,

i am waiting for reply of this question. Please give me solution.
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What do you mean with shadow? Dark parts in the image? Can you give an example?
Hi,

   Actually some images will have shadows, which are taken during time of sunset. I want to get a good algorithm in vc++ or delphi. I am finding some Pdf's in net, they are full of mathematical formula's I need algorithm in C or Pascal. I am attaching the file please see it.

  I got output corected image from net.
shadow-input.JPG
shadow-output.JPG
This is a very complex task. I'm not sure if an algorithm what can do this exists just like that at all...
Hi,


    Please check if any of the algorithm gives at least  partial results. Then I will try to improve it.


   
I don't have an algorithm for this.
Hi experts,


            I saw some of the  articles in the link  given below.And some pdf's also.

                      http://ivrgwww.epfl.ch/~fredemba/shadows.html
                      http://www.cs.sfu.ca/~mark/ftp/Eccv02/shadowless.pdf
                      http://spie.org/x26321.xml?highlight=x2410&ArticleID=x26321
                 But all are giving some differentiation and integration and summation  formulas. But I am not strong in  
                 mathematics. Please can you check the links and can you guide me how to convert the algorithms into C or  
                 Pascal.
       

   
Hi experts,

    In some article I got the point that...."simply adding a constant value, in the log-domain, to the shadow regions resulted in good quality removal."  How to get log domain of an image here?

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ozo
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Hi experts

  Above link is asking login Id . I dont have  Login Id. do we need to pay some amount for getting register?
Hi Ozo,

           Please explain me in details about,"one simple technique is to supress the low frequencies in the Fourier transform of the log of the luminance"