IMAGELG2

Description

Finds the natural logarithm values in image channels, between two image files or within one image file.

Parameters

Name	Type	Caption	Length	Value range
FILI *	String	Input file name	1 - 192
FILO	String	Output file name	0 - 192
DBIC *	Integer	Input raster channel(s)	1 -
DBOC	Integer	Output raster channel(s)	0 -
EMPTYVL	Float	Replacement for invalid numeric value	0 - 1	0.0 - 100000.0 Default: 0.0
MONITOR	String	Monitor mode	0 - 3	ON, OFF Default: ON

* Required parameter

Parameter descriptions

FILI

Specifies the name of the PCIDSK file from which image data is to be converted to natural logarithm values.

FILO

Specifies the name of the output file to receive the natural logarithm of the input image channels.

If the specified output file does not exist, a new PCIDSK file is created. By default, the georeferencing information from the input is copied to the new output file.

DBIC

Specifies the input raster channel(s) to be processed.

Ranges of channels or segments can be specified with negative values. For example, {1,-4,10} is internally expanded to {1,2,3,4,10}. When you are not specifying a range in this way, only 48 numbers can be specified explicitly.

DBOC

Specifies the output image channel(s) produced by taking the natural logarithm of the input image channel(s) (DBIC).

If the output file (FILO) does not already exist, this parameter should be empty.

Duplicate output channels are NOT allowed. The total number of input channels (DBIC) must be equal to the total number of output channels (DBOC).

Output channels must be 32-bit real.

Ranges of channels or segments can be specified with negative values. For example, {1,-4,10} is internally expanded to {1,2,3,4,10}. When you are not specifying a range in this way, only 48 numbers can be specified explicitly.

EMPTYVL

Specifies the number used as replacement for invalid numerical values.

The default value is 0.0.

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

IMAGELG2 takes all the pixel values from the input channel(s) and calculates the natural logarithm value, placing those values in the output channel(s). If an invalid value exists, the value specified in the Replacement Value (EMPTYVL) parameter is used instead.

The output channel(s) must be 32-bit real.

Example

Calculate natural logarithm values for channels 1 to 5 of irvine.pix.

EASI>fili	=	"irvine.pix"	! input file
EASI>filo	=	"orvine.pix"	! output file (will be created)
EASI>dbic	=	1, -5	! input channels
EASI>dboc	=		! five 32R channels will be created
EASI>emptyvl	=		! use default of 0.0

EASI>RUN IMAGELG2