detect shape in image

How can I detect shape(circle,square,triangle) in RGB image(forexample: apple=circle, bread=square)?

Answer 1

[Selva Karna]

RGB = imread('your image'); imshow(RGB); I = rgb2gray(RGB); threshold = graythresh(I); bw = im2bw(I,threshold); imshow(bw) % remove all object containing fewer than 30 pixels bw = bwareaopen(bw,30);

% fill a gap in the pen's cap se = strel('disk',2); bw = imclose(bw,se);

% fill any holes, so that regionprops can be used to estimate % the area enclosed by each of the boundaries bw = imfill(bw,'holes');

imshow(bw) [B,L] = bwboundaries(bw,'noholes');

% Display the label matrix and draw each boundary imshow(label2rgb(L, @jet, [.5 .5 .5])) hold on for k = 1:length(B) boundary = B{k}; plot(boundary(:,2), boundary(:,1), 'w', 'LineWidth', 2) end

[Sahar Mahmoudi]

I run your code but the answer in not related to the automatic shape detection.