Find Threshold on Canny edge image problem
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Dear all experts,
I met a question about how to find the threshold values by giving a fixed edge percentage on canny edge detection problem. I use two 5x5 gradient filters. The code is showns below:
% convolve filterX and filterY with Image to get magnitude gradient and angle
Ix = conv2(Image,filterX); % filterX is a 5x5 gradient filter
Iy = conv2(Image,filterY); % filterY is a 5x5 gradient filter
magnitude = sqrt(Ix.^2+Iy.^2);
angle = atan2(Iy,Ix);
% How to find threshold based on the %percentage? The edge_percentage is the
% proportion of pixels supposed to be treated as potential edge points
max = max(max(magnitude));
min = min(min(magnitude));
% threshold = some percentage work
8 个评论
Image Analyst
2020-5-9
We have no idea what percentage of your objects you expect to be edge points. It depends on the image. Obviously a circle has the lowest proportion of edge points, while an asterisk * shaped blob will have a much higher percentage.
Tony123
2020-5-10
Image Analyst
2020-5-10
Again, it depends on the image. And you can set a threshold to get any binary image you want, but percentage of What? What is your reference? Attach your image.
Tony123
2020-5-11
KALYAN ACHARJYA
2020-5-11
Sorry I am not getting the question.
Image Analyst
2020-5-11
Make it easy for us to help you. Give us code to create filterX and filterY.
Tony123
2020-5-11
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