PCTINT

Description

PCTINT interpolates between non-zero colors in a pseudocolor table (PCT).

Parameters

Name	Type	Length	Value range
InputPCT: Pseudocolor table segment  *	PCT port	1 - 1
OutputPCT: Interpolated PCT layer	PCT port	0 - 1
Report	String	0 - 192	See parameter description

* Required parameter

Parameter descriptions

InputPCT: Pseudocolor table segment

Specifies the pseudocolor table segment (type 121) that holds the pseudocolor table to be interpolated.

OutputPCT: Interpolated PCT layer

Specifies the output layer consisting of the interpolated pseudocolor table.

Report

Specifies where to direct the generated report.

Available options are:

• LOG: generates a report on the terminal (default)
• <modulename.RPT>: appends a report to the module's RPT file
• DISK: generates a report on file "IMPRPT.LST"

Details

PCTINT is used to interpolate non-zero color ranges in a pseudocolor table PCT segment between pre-initialized color values. All values to be interpolated should be black (0,0,0) before running PCTINT.

A typical use of PCTINT is to interpolate colors between known codings. For instance, specific colors might be attached to elevations of 10, 20, 30, and 40 meters, but with PCTINT it is possible to show gradual changes between these values.

A simple linear interpolation scheme is used to compute the new value of (0,0,0) PCT entries based on the previous and next non- zero color entry. If there are no previous and next colors, the (0,0,0) entries will not be replaced. Thus a range of zeros at the beginning or end of the table will remain zero.

Although pure black (0,0,0) values may not be used as a real color, it is possible to use near black (0,0,1) or (1,1,1) instead.