AUTOREG

Description

The automatic registration function, given a reference image and a second input image (target image), applies a filtering and correlation process to determine the best affine transformation for registering the input image to the reference image.

Parameters

Name	Type	Caption	Length	Value range
FILI_REF *	String	Input reference image file	1 - 192
DBIC_REF	Integer	Input reference channel	0 - 1	Default: 1
FILI_IMA *	String	Input image file	1 - 192
DBIC_IMA	Integer	Input image channel	0 - 1	Default: 1
FILO *	String	Output file name	1 - 192
WCHUNKS	Integer	Whitening chunk size	0 - 1	8 - 32 Default: 32
CG_XOFF	Integer	Correlation grid X offset	0 - 1	32 - Default: 128
CG_YOFF	Integer	Correlation grid Y offset	0 - 1	32 - Default: 128
PATCH	Integer	Correlation patch size	0 - 1	0 - Default: 16
SEARCH	Integer	Correlation search window	0 - 1	0 - Default: 32
PFA	Float	Probability of false alarm	0 - 1	0 - Default: 0.10
ISONOFAC	Float	Isolated noise factor	0 - 1	0 - Default: 0.10
REPORT	String	Report mode	0 - 192	Quick links
MONITOR	String	Monitor mode	0 - 3	ON, OFF Default: ON

* Required parameter

Parameter descriptions

FILI_REF

Specifies the input reference image file to which the input image file will be registered.

DBIC_REF

Specifies the image channel that contains the reference image.

FILI_IMA

Specifies the input image file to be registered to the reference image.

DBIC_IMA

Specifies the image channel that contains the image to be registered.

FILO

Specifies the output image file to receive the registered image output.

WCHUNKS

Specifies the size of the chunk of data used to whiten (edge enhance) the reference image and the image to be registered. This value must be a power of 2, and 32 or less. Normally a value 32 is best. A value of 16 will increase processing speed, but at the cost of accuracy.

CG_XOFF

Specifies the correlation grid X offset. This offset is used to ensure that no edge effects are included in the whitening or correlation of the data. The correlation grid X offset must be greater than or equal to half of the search size.

CG_YOFF

Specifies the correlation grid Y offset. This offset is used to ensure that no edge effects are included in the whitening or the correlation of the data. The correlation grid Y offset must be greater than or equal to half of the search size.

PATCH

Specifies the correlation patch size, that is, the size of the image chip for cross-correlation.

SEARCH

Specifies extent of the correlation search range which is the expected mis-registration. The search size must be greater than or equal to the correlation patch size.

PFA

Specifies the probability of false alarm. Decreasing this parameter removes control points that are not likely to be due to image structure.

ISONOFAC

Specifies the isolated noise factor. This parameter is not normally set by the user.

REPORT

Specifies where to direct the generated report.

Available options are:

• TERM: generates a report on the terminal (default)
• DISK: generates a report on file "IMPRPT.LST"
• OFF: turns off report generation
• <filename>: appends a report to the specified file

MONITOR

The program progress can be monitored by printing the percentage of processing completed. A system parameter, MONITOR, controls this activity.

Available options are:

• ON: Turns the monitor ON (default)
• OFF: Turns the monitor OFF (recommended if running in batch or background mode)

Details

Example

Register channel 2 with channel 1 as the reference image. Place the output GCP points into a new GCP segment on the output file (FILO). Set the PATCH to 16 and then set the SEARCH to 32. Use a correlation grid offset of 128 pixels in the X and Y dimensions (CG_XOFF and CG_YOFF). The probability of false alarm (PFA) and the isolation noise factor (ISONOFAC) are both set to 0.1 and 32 whitening chunks (WCHUNKS) are chosen.

EASI>fili_ref	=	"pan_2000.pix"
EASI>dbic_ref	=	1
EASI>fili_ima	=	"pan_2000.pix"
EASI>dbic_ima	=	2
EASI>filo	=	"pan_2000.pix"
EASI>wchunks	=	32
EASI>cg_xoff	=	128
EASI>cg_yoff	=	128
EASI>patch	=	16
EASI>search	=	32
EASI>pfa	=	0.1
EASI>isonofac	=	0.1

EASI>RUN AUTOREG