Phase of an Image

Can anyon helpme in finding thenphase of this image

Answer 1

[Image Analyst]

No, not unless you can get the original gray scale image. You can't do it from a pseudocolored image. If you have the gray scale image, do this

1. subtract the mean: grayImage = double(grayImage) - mean2(grayImage);
2. take the fft2: FT = fft2(grayImage)

Something like:

grayImage = imread('cameraman.tif');
subplot(2, 2, 1);
imshow(grayImage, []);
title('Original Image', 'FontSize', 20);
grayImage = double(grayImage) - mean2(grayImage);
% Take the FFT.
FT = fft2(grayImage);
% Display the phase image.
subplot(2, 2, 2);
imagImage = imag(FT);
imshow(log(imagImage), [])
title('Imaginary part of FT Image', 'FontSize', 20);
% Display the magnitude image.
subplot(2, 2, 3);
realImage = real(FT);
imshow(log(realImage), [])
title('Real Part of FT Image', 'FontSize', 20);

[Arya Gopan]

This ismy Orginal Image I think this is in grey scale. Can you check whether the real and imag phase part I got fromthis image is correct

[Arya Gopan]

[Image Analyst]

I would have expected to see stronger peaks near the upper left corner and upper right corner due to the strong periodic oscillation (or a pair of peaks near the middle if you use fftshift() to translate the origin to the middle of the image). Perhaps it's not noticeable because we used log to display it. Try displaying without log.