how to implement these equations in Matlab?
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I have the following equations
where 
and 
represent the first-order derivative of matrix I . I tried to implement these equations in matlab using the following lines:
and represent the first-order derivative of matrix I . I tried to implement these equations in matlab using the following lines: fx = diff(I,1,2);
fx = padarray(fx, [0 1 0], 'post');
fy = diff(I,1,1);
fy = padarray(fy, [1 0 0], 'post');
Gx = -log10(fx);
Gy = -log10(fy);
however, the value of Gx and Gy are complex numbers which means that these equations don't implemented correctely. does anyone know how to implement these equations correctely in matlab? any help will be appreciated.
5 个评论
VBBV
2020-10-2
编辑：Walter Roberson
2020-10-2
fx = padarray(fx,[0 1],0,'post');
Similarly for fy. The second argument in pad array is size of matrix. Third arg is value
ghada sandoub
2020-10-2
VBBV
2020-10-2
编辑：Walter Roberson
2020-10-2
May be use natural log instead of decimal log
Gx = -log(fx);
John D'Errico
2020-10-2
natural log vs log10 is irrelevant. If one gives complex, than so will the other.
The log of a negative number is complex. Taken to ANY base.
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