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Introduction to the Fourier transform for image processing (2001)

cs.unm.edu

11–20 of 34 posts

Re: Introduction to the Fourier transform for image processing (2001)

#11
Tangent since it is not exclusive to image processing, but When I was studying Fourier Transforms at university I recall that the book "Fourier Series" by Gerogi P. Tolstov helped me a lot. Just throwing it out there in case it helps anyone, including to refresh the definitions the article starts with.

Re: Introduction to the Fourier transform for image processing (2001)

#15
post #7

A better way to eliminate image border effects isnt windowing, but mirrored periodic repetition.

But then this is equivalent to the cosine transform, isn't it? A much better trick than mirrored repetition seems to be the "periodic + smooth" decomposition: https://sbrisard.github.io/posts/20180212-on_the_periodic-pl...

Re: Introduction to the Fourier transform for image processing (2001)

#16
post #12

Nice explanation, but do we still need to use Playboy for reference images?

Conversely, where is the actual Lena reference image? 8-bit pixel depth, 512x512, uncompressed tiff format preferably. Is there a canonical persistent URI someplace?

Re: Introduction to the Fourier transform for image processing (2001)

#17
post #16
post #12

Nice explanation, but do we still need to use Playboy for reference images?

Conversely, where is the actual Lena reference image? 8-bit pixel depth, 512x512, uncompressed tiff format preferably. Is there a canonical persistent URI someplace?

https://web.archive.org/web/20160322020730/https://sipi.usc....

At this point archive services are the best bet for this kind of image.

Re: Introduction to the Fourier transform for image processing (2001)

#18
post #16
post #12

Nice explanation, but do we still need to use Playboy for reference images?

Conversely, where is the actual Lena reference image? 8-bit pixel depth, 512x512, uncompressed tiff format preferably. Is there a canonical persistent URI someplace?

Yes, the "Lenna Story" website: http://www.lenna.org/

A permanent link to the TIFF image itself is: http://www.lenna.org/lena_std.tif

Re: Introduction to the Fourier transform for image processing (2001)

#19
post #9

I always think most of mathematicians is genius. They can hold all concepts and relationships between thems in their mind. The result is the way they explain concepts to broader audience mostly failed. Abstract nonsense for no purpose. I'm fine with it... until i see the application to learn more about theory.

Are you asking what the practical application of 2D Fourier analysis is?

I use it every single day, to correct aberrations in electron microscope images that otherwise obliterates high spatial frequency features and information.

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