How to Plot the discrete Fourier transform on an image ?

How to Plot the discrete Fourier transform on an image ?

[Image Analyst]

What does that mean? The FT of an image is another image, or probably two of them, a real image and a imaginary image. When I think of a plot I think of a line curve. So what are you thinking of when you say that you want to plot a complex image ON an image (presumably the space domain original image)?

[engineer 01]

Question is that

Write a matlab program to input an image

a-) Find the fourier transformation of the intensity values b-) plot the magnitude results obtained in (a) c-) plot the discrete fourier transformation d-)reverse the process e-) plot the image in (d)

i didnt understand this question i didnt find any anwser :(

[Image Analyst]

Perhaps it means to extract just one row of the FT image and plot that with the plot() function??? I'm not sure - it's your call.

[engineer 01]

yes exactly plot is plot() func.

Answer 1

[Youssef Khmou]

 %a
 I=I=im2double(imread('circuit.tif'));

 %b
 F=fftshift(fft2(I));    % surface(abs(F))

 %c
 plot(abs(F))     %  plot not surf 

 %d
 IF=ifft2(fftshift(F));

 %e
 figure, imshow(IF)

Answer 2

[Image Analyst]

Extract a line from the FFt image and plot it.

fftImage = fft2(grayImage);
fftImageRealPart = real(fftImage);
[rows, columns] = size(fftImageRealPart)
lineNumber = floor(rows/2); % Middle row
oneLine = fftImageRealPart(lineNumber, :);
plot(oneLine, 'r-', 'LineWidth', 2);
grid on;

I'm omitting the usual comments and other fancy display/plotting things that I usually include to make it shorter and simpler for you.