User's Guide

MINMAX

Determines the minimum and maximum values in an image

Function:

Determines the minimum and maximum values of an image. If the information is already known, it is printed directly from the image data descriptor record (DDR). If not known, it is computed and the DDR file is updated. There are the standard options for reporting (i.e., Filename,TERM,LP).

Parameters:

IN

Input image. The input image may be BYTE, INTEGER*2, INTEGER*4, or REAL*4 data, and may belong to any user. Single- and multi-band images may be specified. Window and band options may be used, but if a window is specified, the image label will not be updated.

PRINT(TERM)

Output destination. The destination of the output.

  = --:        No Report
  = TERM:      Terminal.  Output is sent to the user's 
               terminal.
  = LP:        Line printer.  Output is sent to the 
               printer defined by $PRINTER.
  = Filename:  User-supplied filename.  Output is sent 
               to the user-supplied file with the 
               extension ".prt".

Examples:

1. LAS> minmax in="myimage.dat(10 10 100 100)" print=term

   MINMAX finds the minimum and maximum pixel values in the window (10 10 100 100) of image MYIMAGE.DAT. The output is written to the terminal with the DDR file being updated if not currently valid.

2. LAS> minmax in=myimages.group print=lp

   The minimum and maximum values are computed for each band in MYIMAGES.GROUP and their DDR files are updated if the user owns the image. The information is written to the printer.

3. LAS> minmax in="#user.imgfil" print=mnmxfil

   MINMAX determines the minimum and maximum values in the input image and write them to a disk file. NO changes are made to the user's file.

Description/Algorithm:

MINMAX checks the image data descriptor record (DDR ) to verify that the minimum and maximum values are valid. If so, these values are displayed. If not, the image is read with the minimum and maximum values retrieved. If windowing is not requested and the user running this routine is the owner of the file, the DDR file is updated. NOTE: the global $MINMAX need not be set.

Nonfatal Error Messages:

None.

Fatal Error Message:

1. [minmax-fatal] Fatal error encountered

   A fatal error was encountered during processing. Processing is terminated. The error message that is displayed immediately preceding this message is the specific error that was encountered.

User Notes:

None.