Thickness measurements of an optical image

Hello everyone,

I wanted to achieve an ambitious goal of automating thickness measurements. We had a 2D slice of our coating and I wanted to construct a baseline where coating meets steel and make a histogram of thickness measurements based on the colour of the pixels.

E.G. Draw a square of Width x above the baseline and increase Y until a threshold is met. The threshold could be when the pixels change HEX/RGB/HSL to an excluded list (e.g. too dark) or some simpler approach.

Image below highlights my goal, does anyone know of an easy way to do this or if there is a script already available?

Best wishes,

Dr. Deacon

Answer 1

[yanqi liu]

im = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/930819/image.png');
bw = im2bw(im);
bw2 = imclose(imfill(bw, 'holes'), strel('disk', 9));
bw3 = bwareafilt(bw2, 1, 'smallest');
bw = bwareaopen(imclearborder(~logical(bw.*bw3)), 5);
s = sum(bw, 2);
[~,id] = max(s);
% bw = imclose(bw, strel('line', 15, 0));
figure; imshow(bw, []); hold on; plot([1 size(bw,2)], [id id], 'r-');

figure; imshow(im, []); 
hold on; plot([1 size(bw,2)], [id id], 'r-');
[r,c] = find(bw3);
cs = round(linspace(min(c), max(c), 30));
for i = 1 : length(cs)-1
    bwi = zeros(size(bw3));
    bwi(:, cs(i):cs(i+1)) = bw3(:, cs(i):cs(i+1));
    [ri, ci] = find(bwi);
    recti = [min(ci) min(ri) max(ci)-min(ci) id-min(ri)];
    hold on; rectangle('position', recti, 'EdgeColor', 'g', 'LineWidth', 2)
end