How to draw this fractal using MATLAB?

Draw a rectangle over an object using Matlab

• I have an image which contains a coin image. Shape of the coin may be rectangle, square, circle, oval and etc. I want to draw a rectangle over the coin and segment the coin from it's background. I can't give x or y values of the rectangle, since coin may be in anywhere in the image. Does anyone know how to do this?

• Answer:

  My answer below assumes that you have already identified the coin and you have a cleaned image (binary would be nice) that you can work with. coin=load('penny.mat'); %#load matlab's stock image img=zeros(256,256); img(65:192,65:192)=coin.P;%# this is an approximation to the sort of image that I think you have Now we need the extents of the image in order to know the size of the bounding rectangle. Since the array is non-zero where there's an image and zero elsewhere, the following gives the length of the sides. sideX=sum(sum(img,1)>0); sideY=sum(sum(img,2)>0); Find the centroid of the image using kmeans. [indX,indY]=ind2sub(size(img),find(img(:)>0)); [~,centroid]=kmeans([indX,indY],1); Now finally overlay the rectangle on top of the image. imagesc(img);colormap(gray);hold on rectangle('Position',([centroid,sideX,sideY]-[sideX,sideY,0,0]/2),'EdgeColor','w');hold off Result: If you have a noisy image (i.e., it's not uniformly zero outside the image, then you'd have to set a threshold to find the bounding box)