shape and color detection

hi sir, after I did color segmentation using HSV color threshold, I want to eliminate the undesired shapes.for example I want to do shape detection. How can I set the area and parameter that I want and eliminate the undesired shapes.I m currently working on road sign detection.based on color segmentation demos: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

it works perfect for color detection. then how can I modify the code so as it can be used for shape detection?many thanks!!!

[Image Analyst]

Sorry - I won't have time to answer this for at least a week - I'm headed off for a week vacation.

[Tulips]

have a good vacation!!!hope that u can spend time guide me answering this question .by the way I m waiting ur answer!

[Ryan]

is post 8 what you're looking for? http://www.mathworks.com/matlabcentral/newsreader/view_thread/295271 (written by Image Analyst)

[Tulips]

hello..actually I'd done the color detection using HSV.It can detect the color for square/circle.However, there're noise of the same color in the image but these noises that not the shape I want..for example.to detect triangular red color, there's also has red blob that is not triangular shape.how can I eliminate that not triangular shape?pls guide me!

[Ryan]

The code in the shared link tells you how to locate shapes, so you could locate the shapes and then do the color detection using HSV on those located shapes. Can you upload a sample image so we can see what we're dealing with?

[Tulips]

here is the link http://www.flickr.com/photos/77154085@N06/7354365440/in/photostream

I just want the circular shape sign(cannot U turn) only.How cud I eliminate other shapes?thanks in advance!

[Ryan]

try another bwareaopen operation with a high value, the area of the circle seems >>> than the pillars.

[Tulips]

how to code it?cant get it.using regionprops?how to do loops if I wanna remove unwanted noise?

[Tulips]

sir I did used this equation in my code circularities = Perimeter^2/(4 * pi (area) and I got the circularities values for the object detection. How can I eliminate the shape that I dont want?in my plotting image it show all detected objects.I want to just only get the circular shape and remove noncircular shape.