MATLAB: Edge detection

Question

Hi,I have a question.

I have an image that I capture from a webcam,here is it: http://www.flickr.com/photos/48230201@N02/5653553606/in/photostream/

I use canny method to detect the edges of all objects this this image. Here is the result: http://www.flickr.com/photos/48230201@N02/5655801861/in/photostream/

How can I remove all noise and just retain the edge of two circles, boundary(two parallel rectangles) and fill in these areas white color,just like this:

http://www.flickr.com/photos/48230201@N02/5654383584/in/photostream/

And How can I determine where is the edge of circle or rectangle to do something like painting rectangle with red and circles with blue.

Thanks a lot.

Answer 1

let me preface - I am no image analyst, but it would seem that segmenting the the color dots would be easy since they are red & green. As for the outer boundary maybe the hough transform would be of some help?