APS

Description

Alters the ground pixel size (in meters) for the database file. APS works only if georeferencing units are either PIXEL or LONG/LAT. If georeferencing units are anything else (such as UTM or METER), use GEOSET to alter the pixel size.

Parameters

Name	Type	Caption	Length	Value range
FILE *	String	Input file name	1 - 192
PXSZ *	Float	Pixel ground-size, in meters	2 - 2	Default: 1.0,1.0

* Required parameter

Parameter descriptions

FILE

Specifies the name of the PCIDSK image file to be altered.

PXSZ

Specifies the horizontal (x) and vertical (y) dimensions of one image pixel, in meters.

Setting this size to a meaningful value is important for ground area calculations (in classification, for example).

Details

APS modifies the pixel ground size (PXSZ) for a specified image database (FILE). It overwrites the pixel size that was specified when the file was created by CIM. The pixel ground size is used for generating statistics and ground area calculations of classified data (performed by MLC and MLR).

APS alters the pixel size on a database file only if the output units for the georeferencing segment are "PIXEL" or "LONG/LAT". This avoids the possibility of inconsistency between the pixel size stored in the master header of the database file and the pixel size derived from the georeferencing segment.

Examples

Alter the ground size of the pixels in the file MSS.PIX to 30 meters in the x-direction and 40.3 meters in the y-direction, assuming that MSS.PIX has not been georeferenced.

EASI>FILE="mss.pix"
EASI>PXSZ=30,40.3

EASI>RUN APS
            

Change the pixel size of the demo image file irvine.pix to 5 by 5 meters. You must run GEOSET first, to default the georeferencing transform.

EASI>FILE="irvine.pix"
EASI>UPLEFT=
EASI>LORIGHT=
EASI>MAPUNITS="PIXEL"

EASI>RUN GEOSET
            

Use APS to alter the pixel size.

EASI>>PXSZ=5,5
EASI>RUN APS