How can we plot pixel difference histogram accurately?

Question

Omar Ali Muhammed 2021-3-8

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/766566-how-can-we-plot-pixel-difference-histogram-accurately

回答： Walter Roberson 2021-3-8

function PDH(img1,img2)
diffImage2 = imfilter(img2, [1, -1]);
diffImage1 = imfilter(img1, [1, -1]);
minValue1 = min(diffImage1(:));
maxValue1 = max(diffImage1(:));
minValue2 = min(diffImage2(:));
maxValue2 = max(diffImage2(:));
[counts2,edge2] = histcounts(diffImage2(:));
[counts1,edge1] = histcounts(diffImage1(:));
end

problem occures when trying plotting edge against counts cause size of edges always exceeds counts by one. However,

edges1 = linspace(minValue1, maxValue1, numel(counts1)) &

edges2 = linspace(minValue2, maxValue2, numel(counts2)) solve the problrm but the shape is not clear unless achieving decimation by certain number e.g 10.

plot(edges1, counts1, edges2, counts2); % Overlapped

plot(edges1(1:10:end), counts1(1:10:end), edges2(1:10:end), counts2(1:10:end));% looks better

Is there more accurate procedure to automatically fit the gragh with proper edges scaling.

Regards