what does it mean "windowing and truncation in fequency domain "

5 次查看（过去 30 天）

显示更早的评论

Zuhaib 2012-12-12

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/56440-what-does-it-mean-windowing-and-truncation-in-fequency-domain

采纳的回答： Image Analyst

how truncation is performed on image using different windows and does that window size depend on original image

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Image Analyst 2012-12-13

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/56440-what-does-it-mean-windowing-and-truncation-in-fequency-domain#answer_68384

Basically you multiply the FFT (spectrum, Fourier Domain) by something that zeros out or attenuates higher frequencies. This "truncates" the spectrum. You choose the window size. It does not depend on the original image size, except that if the width of the truncating window is too huge (wider than the spectrum), you wouldn't be truncating anything. So in a very indirect way it depends on the image size (because hte spectrum size depends on the image size and thus the largest truncating window depends on the image size), but not really directly.

3 个评论
显示 1更早的评论隐藏 1更早的评论

Image Analyst 2012-12-13

I suggest you try a variety of windows such as 32 by 64, 8 by 128, 16 by 16, and observe in each case how it affects the image, and try to understand why.

Zuhaib 2013-5-18

thank you for your assistance

请先登录，再进行评论。

更多回答（1 个）

Arthur 2012-12-12

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/56440-what-does-it-mean-windowing-and-truncation-in-fequency-domain#answer_68349

I used some thing like your question when i worked with Fourier transform. And the analysis could be on the frequecy domain (frequency spectrum)

Or a window of a cicle is used to generate the RMS value of a wave of many of cicles. step by step. (its a way of windowing).

I did not sure if it is your question.

4 个评论
显示 2更早的评论隐藏 2更早的评论

Arthur 2012-12-13

编辑：Arthur 2012-12-13

ok! I think it does not need, but I think it would facilitate the work if it were integer multiple of the main image. As the friend suggested

Image Analyst 2012-12-13

Nothing will be facilitated. Integer multiple (which of course won't have any effect whatsoever) or integer divisor (which is what I think you meant) - none of those are any better or easier than picking some arbitrary window width. It just doesn't matter.

请先登录，再进行评论。

请先登录，再回答此问题。