[Insight-users] Binary Image segmentation

Sun Aug 5 13:49:43 EDT 2007

Hi Luis

Thanks for your comments. Please check this link :

http://www.gopalrk.com/forITKCommunity.html

If this link doesn´t work. Please check following.

Input Image : http://www.gopalrk.com/Input_Image.jpg

Output Image 1: http://www.gopalrk.com/Output_left_top.jpg

Output Image 2: http://www.gopalrk.com/output_Rt_Top.jpg

Output Image 3: http://www.gopalrk.com/Output_Bottom_Left.JPG

Please me know your comments, I will surely go through the approach we
discussed in previous email.

Thanks!

Sincerely
Gopal

Luis Ibanez wrote:
>
> Hi Gopal,
>
>
>      Thanks for better describing your problem.
>
>
> In your case, it seems that  what you are segmenting
> (rather classifying) are the symbols in the document.
>
> Is that right  ?
>
> It will still help a lot if you post somewhere a representative
> image of your problem.
>
>
>
> Before getting to a classification stage you will need to
> define appropriate *descriptors* that capture the uniqueness
> of each one of the symbols.
>
>
> Funny enough, you the first step is to start by considering
> your "binary" image as a grayscale images, and apply for
> example a Hessian image filter.
>
> Then pass the output of  Hessian filter to the EigenAnalysis
> filter and obtain the eigen vectors and eigen values at
> every pixel in your image.
>
> If your image is composed of letters, then you will be able
> to "detect" the linear part of the letters as "ridges"
> in intensity.
>
> You will also be able to detect the crossings between lines
> as regions where the two eigen values are similar.
>
> Look for example at:
>
>      http://www.itk.org/HTML/Curve2DExtraction.htm
>
> You will find the code of this application in the
> InsightApplications checkout.
>
> Note that this applications is only looking for ridges,
> and therefore uses a pattern recognition approach that
> is very specific to ridges.
>
> You may want to extend it in order to capture also
> corners, crossings.... etc.
>
>
> Do you already have a way of defining regions of interest
> around letters ? words ? in the document. If not, you should
> explore a method for it.
>
> Given a region of interest, and having detected particular
> features of the letter traits (ridges, corners, crossings,
> ends), you could use the combination of features in order
> to distinguish some letters from others.
>
> for example the letter "O" doesn't have crossings, ends,
> or corners), while the letter "A" has two crossings, two
> ends, one corner, and 5 segments that look like ridges.
>
>
> Note that code for analyzing vasculature has a lot in common
> with the problems that you will face when performing text
> recognition.
>
>
> Please give it a try at the Curve2DExtractor application,
> and let us know how it goes for you.
>
>
>     Regards,
>
>
>        Luis
>
>
> -------------------------------------
> gkaremore at scai.fraunhofer.de wrote:
>> Hello Dan
>>
>> Thanks for your effort in understanding the problem. I meant by word
>> segmenting is not with respect to medical(or other)image processing, my
>> application is Document image segmentation. In another words , It would
>> be
>> called as multiclass labeling problem. Please see following papers
>> related
>> to binary image segmentation.
>>
>> Bayesian decision feedback for segmentation of binary images
>> Kadaba, S.R.; Gelfand, S.B.; Kashyap, R.L. Acoustics, Speech, and Signal
>> Processing, 1995. ICASSP-95., 1995 International Conference on
>> Volume 4, Issue , 9-12 May 1995 Page(s):2543 - 2546 vol.4
>>
>> Strzelecki M., Segmentation of Binary Images Using Network of
>> Oscillators,
>> 2 Krajowa, Konferencja Komputerowe Systemy Rozpoznawania KOSYR 2001,
>> 28-31
>> May 2001
>>
>> Especially papers from "International Journal of Document Analysis and
>> Recognition (IJDAR) - Computer Imaging, Vision, PR and Graphics "
>>
>> My criterion to cluster is Shape:
>>
>> I want rectangular,square, and horz and verticle line component to be
>> labbled in separation to Text and graphics on the document(Under
>> segmentation/clustering/labeling).
>>
>> currently I am trying with "Feature extraction" section of ITK toolbox.
>> Results are not appreciable. So looking for a different approach using
>> ITK
>> library.
>>
>> Thanks in advance.
>>
>> Sincerely
>> Gopal
>>
>>
>> Dan Homerick wrote:
>>
>>>Hi Gopal,
>>>
>>>I'm not sure if I understand what you mean by segmenting a binary image.
>>>"Segmentation" is typically reducing a grayscale or color image so that
>>>only
>>>a few values are used, done in such a way that each color in the
>>> resulting
>>>image has some semantic meaning. If you're starting with a binary image,
>>>there's not much segmentation that can be done.
>>>
>>>It sounds like what you really want is to cluster (unconnected)
>>> components
>>>of your binary image into logical objects. By what criteria do you want
>>> to
>>>cluster them (spatial proximity, similarity of size, shape, other)? I
>>>don't
>>>think there will be a simple filter to accomplish that, but if you can
>>>provide more details of what you intend to do, the mailing-list may be
>>>able
>>>to provide some guidance.
>>>
>>>Cheers,
>>> - Dan
>>>
>>>On 8/2/07, gkaremore at scai.fraunhofer.de <gkaremore at scai.fraunhofer.de>
>>>wrote:
>>>
>>>>Dear All
>>>>
>>>>Does ITK help in segmenting binary images. In another words ITK
>>>>segmentation library provides function to segment only gray scale and
>>>>color image. Will ITK helpfull in segmenting binary images in  to
>>>>different clusters. (Tried Binary threshold filter, connected component
>>>>algorithms).
>>>>
>>>>Is there any other method by which we can segment binary image in ITK.
>>>>
>>>>Any comments would be appreciable.
>>>>
>>>>Sincerely
>>>>Gopal
>>>>
>>>>Research Scholar
>>>>Fraunhofer Institute
>>>>Germany
>>>>_______________________________________________
>>>>Insight-users mailing list
>>>>Insight-users at itk.org
>>>>http://www.itk.org/mailman/listinfo/insight-users
>>>>
>>>
>>
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