NEWGCP

Description

Reads a ground control point (GCP) segment from a PCIDSK file and extracts the forward and inverse transformations. These transformations are then used to calculate a new set of GCPs, which will be placed in the output file. Normally, IMGFUSE is used to automate the entire fusion process.

Parameters

newgcp(fili, dbseg, dbsn, dbsd, filo)

Name	Type	Caption	Length	Value range
FILI *	str	Input file name	1 -
DBSEG *	List[int]	Input segment number	1 -
DBSN *	str	Output segment name	1 - 8
DBSD	str	Output segment description	0 - 64
FILO *	str	Output file name	1 -

* Required parameter

Parameter descriptions

FILI

Specifies the name of the PCIDSK file that contains the transformation segment.

DBSEG

Specifies the number of the transformation text segment from the input file (FILI).

DBSN

Specifies a name (up to 8 characters) for the output GCP segment.

DBSD

Describes (in up to 64 characters) the contents or origins of the output GCP segment.

FILO

Specifies the name of the PCIDSK file to receive the new output GCP segment.

Details

NEWGCP reads a ground control point (GCP) segment from a PCIDSK file and extracts the forward and inverse transformations. NEWGCP is mainly used to create a new GCP segment that will allow a transformation of the image with REG.

NEWGCP loads in the forward and backward transformation matrices. The new GCP points are then saved to a GCP segment in the output file (FILO). Currently, only the backward transformation matrix is used. Using REG and specifying the new GCP segment, the image may be transformed back to its original coordinates.

This function should be used with TRANSFRM to convert the text segment (DBSEG) used in NEWGCP to the correct format.

Typically, IMGFUSE is used to automate the entire fusion process.

Example

Using text segment number 7 (DBSEG) generated by TRANSFRM and placed in FILI (p2.pix), calculate the new GCPs to perform a backward transformation. Save the new GCP segment in eltoro.pix, in a new segment.

from pci.newgcp import newgcp

fili	=	"p2.pix"
dbseg	=	[7]	# use text segment 7
dbsn	=	'GCP_seg'	# new GCP segment name
dbsd	=	'GCP segment to inverse transform this image'	# segment description
filo	=	'eltoro.pix'	# file to receive new GCP segment

newgcp( fili, dbseg, dbsn, dbsd, filo )