angle — gradient direction of edges
theta = angle(DeltaX, DeltaY)
M x N intensity images, resulting from convolution
with gradient masks in two orthogonal directions
DeltaX is zero,
theta is taken as PI/2.
The function angle obtains the gradient direction theta from images yielded from convolution with gradient masks in direction x and y (DeltaX and DeltaY, respectively).
initial_dir = PWD;
chdir (SIPDIR + 'images');
Img = imread('disks.bmp');
xbasc()
imshow(Img,2);
Dx = edge(Img,thresh=-1, direction='horizontal');
Dy = edge(Img,thresh=-1, direction='vertical');
t = angle(Dx,Dy);
imshow(t,[])
chdir(initial_dir);