Hough 변환의 실현

function [rho,theta,houghSpace] = houghTransform(theImage,thetaSampleFrequency)     %Define the hough space     theImage = flipud(theImage);     [width,height] = size(theImage);     rhoLimit = norm([width height]);     rho = (-rhoLimit:1:rhoLimit);               theta = (0:thetaSampleFrequency:pi);     numThetas = numel(theta);     houghSpace = zeros(numel(rho),numThetas);     %Find the "edge" pixels     [xIndicies,yIndicies] = find(theImage);     %Preallocate space for the accumulator array     numEdgePixels = numel(xIndicies);     accumulator = zeros(numEdgePixels,numThetas);     %Preallocate cosine and sine calculations to increase speed. In     %addition to precallculating sine and cosine we are also multiplying     %them by the proper pixel weights such that the rows will be indexed by     %the pixel number and the columns will be indexed by the thetas.     %Example: cosine(3,:) is 2*cosine(0 to pi)     %         cosine(:,1) is (0 to width of image)*cosine(0)     cosine = (0:width-1)'*cos(theta); %Matrix Outerproduct       sine = (0:height-1)'*sin(theta); %Matrix Outerproduct     accumulator((1:numEdgePixels),:) = cosine(xIndicies,:) + sine(yIndicies,:);     %Scan over the thetas and bin the rhos     for i = (1:numThetas)         houghSpace(:,i) = hist(accumulator(:,i),rho);     end     pcolor(theta,rho,houghSpace);     shading flat;     title('Hough Transform');     xlabel('Theta (radians)');     ylabel('Rho (pixels)');     colormap('gray'); end

 ：http://stackoverflow.com/questions/9916253/hough-transform-in-matlab-without-using-hough-function