Recover a single illuminant from a hyperspectral image
Contents
Syntax:
L = recover_global_illuminant(I);
L = recover_global_illuminant(I, options);
L = recover_global_illuminant(I, options, DEBUG);
Description:
Recover a single global illuminant from a hyperspectral image.
Input:
I: hyperspectral image stored as a 3D array.
options: Structure with the following fields
bitdepth: Is the data type for the spectral cube, i.e. number of bits per
spectral measurement. By fault this is 16.
method: Selects between the following methods
'HRK': Employs the method of Huynh and Robles-Kelly (A Solution of the
Dichromatic Model for Multispectral Photometric Invariance, International
Journal of Computer Vision, 2010).
'FS': Uses the method of Finlayson and Schaefer (Convex and Non-convex Illuminant
Constraints for Dichromatic Colour Constancy, CVPR 2001).
'GW': Uses the Grey World method.
'SG': Uses the Shade of Grey method.
'WP': Uses the White Patch method.
'1stOGE': Uses the 1st order Grey Edge method.
'2ndOGE': Uses the 2nd order Grey Edge method.
drate: Image downsampling rate for the Grey World, Shade of Grey,
White Patch and Grey Edge methods. The default is 1,
i.e. no downsampling.
shadeOfGreyOrder: The order of the L^p mean used for the Shade of Grey method.
The default is 1.
alpha: The value for the regularisation term used for the HRK
(Huynh and Robles-Kelly) method. The default is 50.
patches: Pre-selected patch geometry (can be left empty). This could be a set
of geometry data for image patches whose format is
[Top_left_y, top_left_x, height, width].
DEBUG: Defines the level of debugging information shown at execusion time (0<DEBUG<6).
the default is 0.
Output:
L: a 2D array of size (1 x bands), where bands is the number of wavelength
indexed bands in the input image.
See also:
recover_multi_illuminant