User's Guide

LIST

Generates a printer or terminal listing of pixel values of an image

Function:

Generates a listing of the pixel values of an image. The output can be directed to the terminal, file, or line printer.

If line printer output is requested, the number of pages is calculated and displayed. If the number of pages is greater than five, the user is prompted to indicate whether or not to continue.

Parameters:

IN
Input image. The data type of the input image may be BYTE, INTEGER*2, INTEGER*4, or REAL*4. The input image can be of any size, and it can be a single- or multi-band image. The user may specify a subwindow and/or subband to process a smaller image area. The window size of all input images need not be the same. The input images are not required to be of the same data type.

PRINT(TERM)
Output destination. The destination of the output.


  = 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".
This parameter indicates where to route the output listing of the pixel values in the specified subimage(s). If left at the default (TERM), the output from LIST will be sent to the terminal screen. LP will send a listing to the default printer. Specifying a file name will put a listing into that file name and append it with the extension .prt. Any combination of these three options is allowed.

Examples:

  1. LAS> list in=image.fil

    All the pixel values from IMAGE.FIL are displayed on the terminal screen.

  2. LAS> list in="image.fil(1,1,10,10)" print=(lp,term)

    Pixels 1 through 10 in lines 1 through 10 are written to the line printer and to the terminal screen.

  3. LAS> list in="image.dat(1,1,400,400:2,3)" print=lp

    Bands 2 and 3 of the input image IMAGE.DAT have a 400 x 400 window written to the printer. Since this print-out consists of more than five pages, the user is informed of the number being generated and is prompted whether or not to continue.

  4. LAS> list in="image.dat(1,1,400,400:2,3)" print=imglst

    Bands 2 and 3 of the input image IMAGE.DAT have a 400 x 400 window written to a disk file named IMGLST.PRT. It will be in the same format as the print file.

Description/Algorithm:

LIST processes one input band at a time. When the pixel values for one input image band are all output, LIST reinitializes the process for the next band (if more than one was requested).

Images with BYTE, INTEGER*2, INTEGER*4, or REAL*4 pixels may be output on the terminal screen, specified disk file, or the line printer. If printer output is chosen, the user is prompted whether or not to continue only if more than five pages of output will be generated. If terminal output is chosen, the pixel values are printed line by line.

Regardless of which output destination is chosen, the number of pixel values displayed on one line of output is determined by the input data type. BYTE, INTEGER*2, and INTEGER*4 pixels are written using integer formats, while REAL*4 values are written using an exponential format.

Nonfatal Error Message:

  1. [list-warn] Nonfatal error encountered

    The message that is displayed immediately preceding this message is the specific error that was encountered. Processing continues.

Fatal Error Messages:

  1. [list-fatal] Fatal error encountered--No output created

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

  2. [list-nospace] Unable to allocate enough buffer space

    LIST was unable to allocate the amount of space needed to process the image.

  3. [list-quit] LIST quitting--No output created

    If printer output is requested and the user does not respond with Y to the continuation prompt, this message is generated and processing terminates.

  4. [list-close] Error closing temporary file for fileutil

    A temporary file is created for LIST output as input to FILEUTIL, which routes to the PRINT parameter specifi- cation. When a fatal error occurs, this file needs to be closed. The above message message appears when this closing is unsuccessful.

User Notes:

  1. Be careful when listing multi-band images. If no window is given, each band is listed. As in the case of large images, this can be wasteful and should be done carefully.

  2. If the PRINT parameter is set to LP, the print file is routed to the system printer with a width of 132 columns. Keep in mind that if the TAE global $PRINTER is set to an alternate printer, the print file--headings included-- will, nonetheless, be sent in 132 column format. This may result in truncated listings and/or improperly formatted headings if the width of $PRINTER is not 132.