Counting teeth
This is an example of how to use Cell Mode in the MATLAB Editor.
Contents
Read in the image
gearImage = imread('gear.jpg');
imshow(gearImage)
Convert to grayscale and threshold
gearGray = rgb2gray(gearImage); gearBW = gearGray > 105; imshow(gearBW)
Remove the small spots
Clean up the image.
gearBW = bwareaopen(gearBW, 20); imshow(gearBW)
Fill in the holes
gearBW = imfill(gearBW, 'holes');
imshow(gearBW)
Find the circle that encloses the gear
rp = regionprops(double(gearBW), 'all'); xy = rp.ConvexHull; line(xy(:,1),xy(:,2),'Color','yellow','LineWidth',2)
Shrink the circle to expose the gears
[r,c] = size(gearBW); mask = poly2mask(xy(:,1), xy(:,2), r, c); maskEroded = imerode(mask, ones(16)); rp = regionprops(double(maskEroded), 'all'); xy = rp.ConvexHull; line(xy(:,1),xy(:,2),'Color','red','LineWidth',2)
Subtract the hub
teeth = gearBW; teeth(maskEroded) = 0; imshow(teeth)
Label and count the teeth
Output to the MATLAB command window is captured in the HTML file.
[teethLabel, numTeeth] = bwlabel(teeth); imshow(label2rgb(teethLabel, @jet)) numTeeth
numTeeth =
40
