thm.white noise remove2

From DavinciWiki

Description

White noise removal algorithm for THEMIS radiance cubes

Each band of radiance is converted into a percentage of the luminosity, the integral of the radiance over all bands. This 'relative color space' is then convolved and then multiplied by the luminosity to regain radiance units. The assumption behind the algorithm is that no two adjacent pixels in any band should contribute a signifantly large difference in the percentage of the total luminosity. This assumption is obviously wrong, but it is useful for accentuating geomorphological information while corrupting the spectra.

This algorithm is part of a more robust white noise removal process involving pca called rmnoise_pca. When used by itself the data is unusable for spectral information or to produce meaningful emissivities.

Arguments and Return Values

Arguments: A THEMIS radiance cube

Return Value: A THEMIS radiance cube with white noise removed

Usage

Syntax: thm.white_noise_remove2(data = VAL [, filt = INT] [, b10 = INT] [, ignore = FLOAT])

'data' - Any 3-D radiance array.

'filt' - An optional size of the smoothing kernel. Default is 7.

'b10' - An optional z location of THEMIS band 10. Default is 10.

'ignore' - An optional non-data pixel value. Default is -32768.

Examples

dv> a
358x1500x10 array of float, bsq format [21,480,000 bytes]

dv> a1=thm.white_noise_remove2(a)
358x1500x10 array of float, bsq format [21,480,000 bytes]

Images

Images in order are: Original radiance, radiance with white noise removed and emissivity after white noise removal