#  README.txt -- Contents of dbftp.essc.psu.edu/pub/data/las

This directory contains the source code of the LAS image analysis
software, release 7.4 (November 2001) as distributed by the USGS EROS
Data Center.  The unmodified EDC distribution is in files

    las_74_src.tar.gz
    lasinstall_74.txt
    release_notes_las74.txt
    tae_build_74.patch
    tae_build_patch_74.txt

The two tae_build* files were provided after the main release to patch
LAS to run under current versions of Linux.  The two Xwindows
applications, TIEPTS and XID (the image display module) do not work
correctly under LAS.  If anyone has successfully fixed them, other LAS
users would greatly appreciate sharing the fix.

So far as I can determine, LAS may be freely distributed.  The file
lasinstall_74.txt contains the following statement under the heading
"LAS Disclaimer":

    The USGS EROS Data Center (EDC) has provided LAS to outside
    users since 1983 and continues to provide limited support.
    Originally, the LAS and ADAPS system was developed to support
    research and development of image processing applications within
    NASA and the USGS and has migrated to provide special services
    for EDC image production.  Since the software is public-domain,
    it is available to any government or private institution.

Support for LAS development at EDC ended in 2004; as of early 2006, the
EDC site for distributing LAS was no longer accessible.

Several additional modules developed at Penn State may be of interest to
other users.  I have included them here.

    annoteps.tar.gz  Enhanced version of ANNOTATE, supporting standard
		     PostScript fonts.

    convert.tar.gz   Converts between LAS image format and many of the
		     formats supported by the ImageMagick "convert"
		     utility.  (Requires getimgsz.tar.gz).

    getimgsz.tar.gz  Returns LAS image size and data type to a TAE/LAS
		     procedure.

    histo2.tar.gz    Creates a two-dimensional histogram from two image
		     bands; output is in LAS image format.

    imdisplay.tar.gz Displays an LAS image using the ImageMagick
		     "display" utility.  This provides a limited display
		     capability for systems (currently Linux) on which
		     the LAS XID program does not work properly.

    mergefour.tar.gz Uses linear weighting functions to seamlessly merge
		     a two-by-two array of overlapping images which
		     typically represent the northwest, northeast,
		     southwest, and southeast quandrants of a region of
		     interest.

    regrid.tar.gz    Reprojects an image to a (usually) coarser grid,
		     computing the mean (for continous-valued images) or
		     mode (for categorical images, such as land cover
		     class) for all the input pixels covered by each
		     output grid cell.

    surface.tar.gz   Fits a smoothed surface to an elevation-dependent
		     variable using the algorithm described in
		     P. E. Thornton, S. W. Running, and M. A. White,
		     "Generating surfaces of daily meteorological
		     variables over large regions of complex terrain",
		     Journal of Hydrology 190 (1997), pp. 214-251.
		     CAUTION:  This program has not been extensively
		     tested or exercised.

    zoom.tar.gz	     Enhanced version of ZOOM, permitting adding random
		     variation to the input pixel value when expanding
		     the image, and taking the mean of the input pixels
		     when reducing the size of the image.

A version of the LAS HTML documentation customized for the Penn State
environment, including HTML versions of the TAE user and programmer
manuals, are available at http://dbwww.essc.psu.edu/lasdoc.

I have not completed our local port of LAS to Linux, nor have I
extensively exercised the Linux version.  There are some additonal
modifications which I hope to make available when I complete them.

Please direct questions and comments to raw@essc.psu.edu.

Dick White 
25 Apr. 2007

========================================================================
    Richard A. White
    Center for Environmental Informatics
    Earth and Environmental Systems Institute
    The Pennsylvania State University
    2217 Earth-Engineering Sciences Bldg.
    University Park, PA 16802-6813

    Tel. (814) 865-9905
========================================================================