A Computational Introduction to Digital Image Processing, 2nd Edition

Image Segmentation 263

Python

In : c30 = fftshift(fft(cr[:,30]))

In : c30l = np.log(1+np.abs(c30))

In : plt.plot(c30l)

To obtain the Fourier slice, the easiest way is to rotate the transform of the image and then

read off the center row:

MATLAB/Octave

>> cl = log(1+abs(cf));

>> cl30 = imrotate(cl,30);

>> [rs,cs] = size(cl30);

>> plot(cl30(floor(rs/2),:))

or with

Python

In : cl = np.log(1+np.abs(cf))

In : cl30 = tr.rotate(cl,30,resize="True",order=3)

In : rs = cl30.shape[0]

In : plt.plot(cl30[rs/2,’’])

The results are shown in Figure 9.42. The plots are remarkably similar, with differences

accounted for by rounding errors and interpolation when rotating. This means, ...