User's Guide

IMDISPLAY

Display an LAS image using the ImageMagick "display" utility.

Function:

IMDISPLAY uses the ImageMagick "display" utility to display a one- or three-band LAS image. Band selection and image windowing are supported.

If the image data type is not byte, the minimum value for all specified bands and the maximum for all specified bands are determined; program MAP is used to adjust the range to 0-255.

Parameters:

IN
Name of LAS image to display. The image specification may contain spatial and/or spectral windowing, and may specify a logical image comprised of two or three actual image files. However, the total number of input bands specified must be either 1 or 3.

Examples:

  1. LAS> imdisplay in=newdem

    A single channel image is converted from type I*4 to type BYTE, with the values adjusted to range from 0 to 255, and then displayed.

  2. LAS> imdisplay in="many_channel_image(101,251,600,800:6,12,18)"

    The specified spatial window of three bands selected from an input image having a larger number of bands are displayed.

Description/Algorithm:

The specified bands and spatial window of the input image is copied to a temporary file. The dimensions, number of bands, and data type of this temporary image are determined.

If the data type is not BYTE, IMDISPLAY uses process MAP to adjust the range from the minumum value of any band to the maximum value of any band in the temporary file to the range 0 to 255, with image data type BYTE.

When the user exits the ImageMagick "display" utility, IMDISPLAY deletes the temporary files.

Nonfatal Error Messages:

    None.

Fatal Error Messages:

  1. [imdisplay-bands] "Input must have either 1 or 3 bands"

    The ImageMagick "display" utility primarily supports images having either one or three bands. IMDISPLAY cannot handle other types of input.

User Notes:

  1. The ImageMagick "display" module must be available in one of the binary directories included in the user's PATH variable.

  2. Although ImageMagick claims to support image depths of both 8 and 16 bits, the LAS DISPLAY currently only supports 8-bit image depth.