Why are the results produced by fft2 and those produced by fft different?

조회 수: 3 (최근 30일)
William
William 2017년 7월 29일
편집: William 2022년 9월 13일
I conducted Fourier transform on an imag through two operations:
Firstly:
pic='pic.jpg';
pic_read=rgb2gray(double(imread(pic)));
results1= fft2(pic_read);
Secondly:
for c=1:size(pic_read,2)
fft_column(:,c)=fft(pic_read(:,c));
end
for r=1:size(pic_read,1)
results2(r,:)= fft(fft_column(r,:));
end
isequal(results1,results2)
ans =
0
I want to know why the results of the two above operations are different ?
Thanks

답변 (1개)

Ahmed raafat
Ahmed raafat 2017년 7월 30일
use tic toc commands
tic
... your code...
t=toc; % time in second
freq=your images/t
  댓글 수: 2
William
William 2017년 7월 30일
Thank you. But are you sure that you answered the right question?
Ahmed raafat
Ahmed raafat 2017년 7월 30일
I guess this is the only method to calculate the time

댓글을 달려면 로그인하십시오.

카테고리

Help CenterFile Exchange에서 傅里叶分析和滤波에 대해 자세히 알아보기

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!