max radial frequency of an image

@image analyst sr, i want to find the maximum radial frequency of an image. can u please help me how to get it.

Thanx

Answer 1

[Image Analyst]

How are you defining max? The max frequency is defined by the sampling distance, though your actual image may not have frequencies that approach that. For example your max frequency may be 1/1000 but if you have a really smooth broad Gaussian in the image, your max Frequency may be only a quarter of that or less.

[parul mittal]

Sr I have to find the polar fourier transform of the image for that I need the values maximum radial frequency and maximum angular frequency. Kindly guide me Sr how can I get them..

Thanx

[Image Analyst]

The maximum radial frequency that is capable of being recorded depends solely on how many pixels you have in the x or y direction. Whether you actually have any frequencies that high depends on your image content. It could be that anything way out there is simply noise. I don't know of any special code for polar fft. Just use regular fft. You could always create two new images from the cartesian image where you have the radius and the angle computed from each frequency component (each pixel in the cartesian FFT image).