Calculate the image gradient
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I use the function imgradientxy to get the Gx and Gy firstly. Then obtain the direction of the gradient.
some codes like:
% code
b = zeros(100);
b(1:4:end,:) = 1;
[Gx, Gy] = imgradientxy(b);
theta = atan(Gy./Gx);
The image only has some horizontal lines. So The Gx is all zeros and the theta have a lot NAN. What should I do to get the gradient for this image and for other?
2 个评论
naser telesi
2017-3-1
if Gx is zero then let Gx = 1 to avoid divide by zero problem
Matt J
2017-3-1
if Gx is zero then let Gx = 1 to avoid divide by zero problem
But theta will be wrong...
采纳的回答
Matt J
2013-9-23
Use atan2 instead
theta=atan2(Gy,Gx);
2 个评论
Donghui Sun
2013-9-23
Image Analyst
2013-9-23
Like I said, imgradient() already gives that to you as Gdir - see the help. No need to do it yourself with atan2.
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