CROSSMOD

Description

Cross-correlates the 'original' image band with the 'reference' band to produce B0 and B1 coefficient matrices. Normally, IMGFUSE is used to automate the entire fusion process. IMGLOCK can be used to automate the image locking process.

Parameters

Name	Type	Caption	Length	Value range
FILI_ORG *	String	Input file name (original image)	1 - 192
FILI_REF *	String	Input file name (reference image)	1 - 192
FILO *	String	Output file name	1 - 192
DBIC_REF *	Integer	Input reference image channels	1 - 1
DBIC_ORG *	Integer	Input original image channel	1 - 1
DBOC_B0 *	Integer	Output channel for B0	1 - 1
DBOC_B1 *	Integer	Output channel for B1	1 - 1
MAXGAIN	Float	Maximum model gain	0 - 1	0.0 - 255.0 Default: 3.0
KSIZE	Integer	Kernel size	0 - 1	1 - 100 Default: 7
REPORT	String	Report mode	0 - 192	Quick links
MONITOR	String	Monitor mode	0 - 3	ON, OFF Default: ON

* Required parameter

Parameter descriptions

FILI_ORG

Specifies the PCIDSK file that contains the image data to be locally modeled by the reference file. The dimensions of FILI_ORG and FILI_REF must be the same.

FILI_REF

Specifies the PCIDSK file that contains the reference image data. The dimensions of FILI_ORG and FILI_REF must be the same.

FILO

Specifies the output PCIDSK file to receive the B0 and B1 (32R) coefficient images.

DBIC_REF

Specifies the image channel to be used as the image reference in the algorithm. This should be an 8-bit unsigned image channel.

DBIC_ORG

Specifies the input channel that contains the original image. This should be an 8-bit unsigned image channel.

DBOC_B0

Specifies the image channel to receive the output B0 image. This should be a 32-bit real image channel.

DBOC_B1

Specifies the image channel to receive the output B1 image. This should be a 32-bit real image channel.

MAXGAIN

Specifies the maximum model gain to be used for the modeling process.

Lower maximum gain values reduce the tendency of the algorithm to introduce noise into otherwise low texture or structured areas such as water regions. A typical starting value for this parameter is 3. If there is resulting noise in the water regions, reduce the maximum gain value. Note that reducing this value to less than 1 will result in blurred edges.

KSIZE

Specifies the size of the linear kernels over which the cross-correlation modeling is performed.

Correlation is performed on a window size of ( 2 * KSIZE + 1 ) pixels. Sizes of less than 3 will produce noisier images; sizes greater than 7 will blur edges.

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

CROSSMOD performs a cross correlation between the reference image and the original image. A horizontal and vertical kernel of KSIZE length is created. As this kernel scans across the window, the merit of both the horizontal and vertical kernels is evaluated. The correlation coefficients (B0 and B1) of the kernel with the best merit are then saved to the output file.

When spatial enhancement is performed, the amount of detail from the reference image that will be fused into the output image can be controlled by specifying the maximum gain (MAXGAIN); this parameter sets the upper limit of the B1 coefficient of the kernel with the best merit. For example, setting the maximum gain to 0 produces the original input file as output; there will be no spatial enhancement.

Example

In the multispectral image database ms.pix, cross model channel 3 (the original image) with channel 2 (the reference image), and place the B0 image to channel 11 and the B1 image to channel 12 in ms.pix. Use a window width of 100 pixels, MAXGAIN of 3, and a kernel size of 7.

EASI>fili_org	=	"ms.pix"
EASI>fili_ref	=	"ms.pix"
EASI>filo	=	"ms.pix"
EASI>dbic_org	=	3
EASI>dbic_ref	=	2
EASI>dboc_b0	=	11
EASI>dboc_b1	=	12
EASI>maxgain	=	3
EASI>ksize	=	7

EASI>RUN CROSSMOD