CDQB

Description

CDQB reads QuickBird, WorldView-1, and WorldView-2 imagery from a TIFF- or NITF-format CD when satellite orthorectification is required. CDQB automatically creates a PCIDSK file, reads all the requested imagery channels from CD, and saves the satellite path information to a segment. The output file from CDQB is used as input to CATALYST Professional OrthoEngine.

Parameters

cdqb(fili, filo, linkfile, cdic, tex1)

Name	Type	Caption	Length	Value range
FILI*	str	Input file name	1 -
FILO*	str	Output file name	1 -
LINKFILE	str	Create linked file	0 - 3	YES | NO Default: NO
CDIC	List[int]	CD input channel(s)	0 - 8	1 -
TEX1	str	Descriptive text	0 - 64

* Required parameter

Parameter descriptions

FILI

Specifies the full path and file name of the input product image file.

FILO

Specifies the name of the PCIDSK file that will receive the processed data. The output file is created automatically and must not already exist.

LINKFILE

Specifies whether to create a linked output file.

If YES, the function creates an output file in which the image channel is linked to the original imagery channel. The orbital segment will still be created in the specified output file.

If NO, the function creates a new PCIDSK output file to receive the data. This is the default behavior.

CDIC

Specifies the list of channels to read from the CD. Up to 16 channels may be specified.

For each channel, a corresponding channel is created in the output PCIDSK file. Duplicate channels are NOT allowed.

If LINKFILE is set to YES, all channels are linked.

If this parameter is not specified, all channels are transferred.

TEX1

Optionally specifies a line of text that describes the file. Typically, this contains information that identifies the location of the data and the CD reference number.

Details

CDQB is part of the satellite orthorectification component. It reads both QuickBird and WorldView (WorldView-1 and WorldView-2) data sets in TIFF or NITF format when satellite orthorectification is required. The corresponding metadata file must also exist in the same directory. CDQB automatically creates a PCIDSK file, reads all the requested imagery channels from CD, and saves the satellite path information in a segment.

CDQB extracts the geographic coordinates from the CD on the scene center and on the 4 corner points. The values are stored in the output orbit segment. These points can be used as ground control point (GCP) input for an approximate correction, which is useful when GCPs are unavailable for an area. Note, however, that using geographic coordinates may not produce very accurate results.

If the LINKFILE parameter is set to NO, the generated file is automatically created with the dimensions required to hold all of the requested data. Ensure that sufficient disk space is available before running CDQB. If LINKFILE is set to YES, the image channel is not created; it is linked to the image channel of FILI. For stereo data, the LINKFILE parameter is ignored and a new file is created because rotation is required when reading the data.

Example

The user has received a QuickBird product in Tiff format CD and wishes to perform orthorectification on the data. The user wishes to extract channel 1 and store them in the file qb.pix.

from pci.cdqb import *

fili = r"/cdrom/02APR18160856-P1BS-000000010813_01_P001.TIF" 	# Linux/Unix
fili = r"D:\02APR18160856-P1BS-000000010813_01_P001.TIF" 	# Windows
filo = "qb.pix"					# output file name
cdic = [1]					# input channel number
linkfile = "NO"
tex1 = "Richmond Hill, Canada"

cdqb (fili, filo, linkfile, cdic, tex1)

References

Toutin, Th. "Analyse math\u00c3\u00a9matique des possibilit\u00c3\u00a9s cartographiques du syst\u00c3\u00a8me SPOT". Th\u00c3\u00a8se de Docteur-Ing\u00c3\u00a9nieur en Sciences G\u00c3\u00a9od\u00c3\u00a9siques, ENSG, Paris, France, 1985.

Toutin, Th. and Carbonneau Y. "La multi-st\u00c3\u00a9r\u00c3\u00a9oscopie pour les corrections d'images SPOT-HRV", Canadian Journal of Remote Sensing, Vol. 15, No. 2 (September 1989) p110. (Also available in English from the Canada Centre for Remote Sensing.)