SPOTBLUE

Description

Parameters

spotblue(fili, dbic, filo)

Parameter descriptions

FILI

Specifies the path and file name of the SPOT multispectral image, in a GDB-supported format. Multispectral scenes from all SPOT satellites are supported.

DBIC

Specifies the input Red, Green, and Near Infrared band channels in the image.

FILO

Specifies the path and file name of the output image. The output will contain all content in the input file, as well as the simulated blue band.

Return Value

Returns: Execution status

Type:  PCI_INT

The return value is 0. This function returns only if it executes successfully; otherwise, it throws an exception.

Details

SPOTBLUE generates a simulated blue band from an multispectral image and adds the simulated blue band to the output. Multispectral scenes with red, green and near-infrared bands are supported.

The optional DBIC parameter specifies the input file channels that contain, at minimum, the red (R), green (G), and near-infrared (I) bands of the multispectral image.

After successful completion of processing, the output file will receive the original content transferred from the input, as well as a synthesized blue band added.

The simulated blue band is created according to the algorithm in the paper by Patra et al. (2006) listed in the References section. The blue band (B) is created as a linear combination of the three input bands as follows:

B = a + bG + cR + dI

The above coefficients are specific for unsigned 8bit and will be adjusted accordingly for image with other bit depth as described in the reference literature.

The natural color images (when the output color product is RGB), or synthesized blue band (when the output color product is Synthesized Blue Band) are intended for display and presentation. They should not be used for quantitative analyses, classification, or other information retrieval tasks.

Example

This example assumes the input file S4H1070726184402I_ortho.pix is available. Channel 1, 2, 3 correspond to red, green, near-infrared.

from pci.spotblue import spotblue

fili		= 'S4H1070726184402I_ortho.pix'
dbic		= [1,2,3]
filo		= 'S4H1070726184402I_ortho_RGB.pix'

spotblue(fili, dbic, filo)

Acknowledgements

SPOTBLUE was partially funded by PRECARN and the Department of Alberta Advanced Education and Technology.

The implemented algorithm was selected and tested by the Alberta Terrestrial Imaging Center.

References

Patra, S.K., M. Shekher, S.S. Solanki, R. Ramachandran and R. Krishnan, (2006). "A technique for generating natural color images from false color composite images." International Journal of Remote Sensing, 27(14): 2977-2989.