by：黄光耀
%% Step 1: Load Image rgb = imread(‘2019.png’); imshow(rgb) %% Step 2: Determine Radius Range for Searching Circles d = imdistline; delete(d) %% Step 3: Initial Attempt to Find Circles gray_image = rgb2gray(rgb); imshow(gray_image) [centers,radii] = imfindcircles(rgb,[35 43],‘ObjectPolarity’,‘dark’); %% Step 4: Increase Detection Sensitivity [centers,radii] = imfindcircles(rgb,[20 25],‘ObjectPolarity’,‘dark’, … ‘Sensitivity’,0.9); %%Step 5: Draw the Circles on the Image imshow(rgb) h = viscircles(centers,radii); [centers,radii] = imfindcircles(rgb,[20 25],‘ObjectPolarity’,‘dark’, … ‘Sensitivity’,0.92); length(centers) delete(h) % Delete previously drawn circles h = viscircles(centers,radii); %% Step 6: Use the Second Method (Two-stage) for Finding Circles [centers,radii] = imfindcircles(rgb,[20 25],‘ObjectPolarity’,‘dark’, … ‘Sensitivity’,0.92,‘Method’,‘twostage’); delete(h) h = viscircles(centers,radii); [centers,radii] = imfindcircles(rgb,[20 25],‘ObjectPolarity’,‘dark’, … ‘Sensitivity’,0.95); delete(h) viscircles(centers,radii); %% Step 7: Why are Some Circles Still Getting Missed? imshow(gray_image) %% Step 8: Find ‘Bright’ Circles in the Image [centersBright,radiiBright] = imfindcircles(rgb,[20 25], … ‘ObjectPolarity’,‘bright’,‘Sensitivity’,0.92); %% Step 9: Draw ‘Bright’ Circles with Different Color imshow(rgb) hBright = viscircles(centersBright, radiiBright,‘Color’,‘b’); %% Step 10: Lower the Value of ‘EdgeThreshold’ [centersBright,radiiBright,metricBright] = imfindcircles(rgb,[20 25], … ‘ObjectPolarity’,‘bright’,‘Sensitivity’,0.92,‘EdgeThreshold’,0.1); delete(hBright) hBright = viscircles(centersBright, radiiBright,‘Color’,‘b’); %% Step 11: Draw ‘Dark’ and ‘Bright’ Circles Together h = viscircles(centers,radii);
