Analysis Enhancements
The following enhancements have been made to IDL's data-analysis functionality for the 7.1 release:
New Image Processing Filter Routines
Six new image filtering routines have been added to IDL in this release. All are written in the IDL language.
BANDPASS_FILTER
Applies a bandpass filter to a one-channel image.
BANDREJECT_FILTER
Applies a band reject filter on a one-channel image.
ESTIMATOR_FILTER
Applies an order statistic noise-reduction filter to a one-channel image.
LEAST_SQUARES_FILTER
Reduces degradation and noise in an image based on the mean and variance of the degradation and noise.
MEAN_FILTER
Applies mean filter noise reduction on a one- or multi-channel image.
WIENER_FILTER
Reduces degradation and noise in an image by statistically comparing it with an undegraded image.
CENTER keyword to FFT
The CENTER keyword to the FFT procedure calculates a centered Fourier transform. In the forward direction, the resulting Fourier transform has the zero frequency location shifted to the center of the array. In the reverse direction, the input is assumed to be a centered Fourier transform.
This keyword is added as a convenience. The following two examples are equivalent:
Example One: Without the CENTER Keyword
imageSize = SIZE(image, /DIMENSIONS) fftUncentered = FFT(image) center = imageSize/2 + 1 fftCentered = SHIFT(fftUncentered, center)
Example Two: With the CENTER Keyword
