[Insight-users] Binary Image segmentation
gkaremore at scai.fraunhofer.de
gkaremore at scai.fraunhofer.de
Wed Aug 15 10:56:06 EDT 2007
Dear Luis
Thanks for your reply. The results are realy good using
/InsightApplications/Curves2DExtractor. But That I will need later to
extract each feature from an extracted image. Currently I am trying to
extract a part of image ie. http://www.gopalrk.com/Output_Bottom_Left.JPG
from original image http://www.gopalrk.com/Input_Image.jpg automatically.
This is the flow of my work.
Input Image -> CannyEdgeDetectionImageFilter
->MathematicalMorphologyGrayscaleFilters (Image after multiple Dilation)
->itkConnectedComponentImageFilter->RelabelComponentImageFilter
This will give me an image with different label and size.
My Requirement : I want to locate the position of centroid (Pixel
location) of each label. So that After getting the centroid location, I
can map that point in original image and crop a region of interest which I
want around the centroid point so as to get
http://www.gopalrk.com/Output_Bottom_Left.JPG from
http://www.gopalrk.com/Input_Image.jpg
After getting a this I will need your code Curves2DExtractor descibed in
your previous mail which is realy promising.
I am looking forward to hear from you.
Thanks!
Sincerely
Gopal Karemore
Zimmer no: 332
The Department of Bioinformatics
The Fraunhofer Institute for Algorithms and Scientific Computing
St. Augustin, Bonn
Germany 53754
Email : gkaremore at scai.fraunhofer.de
gopal.karemore at gmail.com
Contact: +49-2241-142537
Internet : http://www.gopalrk.com
Luis Ibanez wrote:
> Hi Gopal,
>
> Thanks for posting your images.
>
> They are quite interesting.
>
> ITK can provide you the low level "feature detection" functionalities that
> you need here. For example : line, corner, crossing detection.
>
> All based on analyzing the parametric space of the Hessian image.
>
> We just run a quick test with the application:
>
> /InsightApplications/Curves2DExtractor/Curves2DExtractor
>
> By loading as input image:
>
> Output_Bottom_Left.JPG
>
> Setting the Sigma value ( for the Hessian) to 0.8 and
> using the following parameters in the "Spatial Function" panel:
>
> Angle Z = 34.5
> Aperture X = 18.8
> Aperture Y = 3
> Apex Coordinates
> X= 0.3
> Y = 0
> Z = 1
> Top Plane = 0.05
> Bottom Plane = 2
>
> We put a screen shot of the results at:
>
> http://public.kitware.com/pub/itk/UsersITK/Curve2DExtractor/
>
>
> The results indicate that you should be able to extract many
> of the features, *BUT* you will need higher resolution images.
> (Maybe 5 to 10 times higher that what you sent. This need for
> higher resolution is related to the use of Second derivative
> operators in the Hessian.
>
>
> When you click on the button : "Parametric Space"
>
> You will see appearing a scatter plot of the pixel values
> in the parametric space. Different features (lines, corners, crossings)
> are located in different places of this parametric space. For example,
> Lines are located along in the plane Y=0, along the spine of a line
> that goes from the apex of the truncated pyramid to a middle point
> in the X axis.
>
>
> You will have to work out different spatial functions to capture the
> points
> corresponding to every particular feature.
>
>
> Please let us know if you have further questions,
>
>
> Thanks
>
>
> Luis
>
>
>
> -------------------------------------------------------------------------
> On 8/5/07, gkaremore at scai.fraunhofer.de <gkaremore at scai.fraunhofer.de>
> wrote:
>>
>> 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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>> >
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