Name

filt_gaussb - Gaussian band-pass Fourier filter

Usage

output = filt_gaussb(image, sigma, center, pad)

Input

image

input image (can be either real or Fourier)

sigma

standard deviation of the Gaussian function in absolute frequency units `f_a`.

center

frequency in absolute frequency units `f_a` at which the filter reaches maximum (=1).

pad

logical flag specifying whether before filtering the image should be padded with zeroes in real space to twice the size (this helps avoiding aliasing artifacts). (Default pad = False).

Output

output

filtered image. Output image is real when input image is real or Fourier when input image is Fourier

Method

Fourier transform of the input image is multiplied by a radially symmetric Gaussian filter:

• `G(f) = exp(-(f-center)^2/(2 sigma^2))`

Reference

Gonzalez, R. F., Woods, R. E., 2002. Digital Image Processing. Prentice Hall, Upper Saddle River, NJ.

Author / Maintainer

Pawel A. Penczek

Keywords

category 1

FILTER

category 2

FOURIER

Files

filter.py

Maturity

stable

works for most people, has been tested; test cases/examples available.

Bugs

None. It is perfect.