IMG2DXB
                          Image to DXB

                               by
                         David L. Walker
                         Copyright 1990

     This program is provided on a shareware basis and is intended
for review by anyone. Continued use requires the payment of $25.00
to the author at the following address:

                         David L. Walker
                       Walker Engineering
                          P.O. Box 366
                    Staffordsville, VA 24167

LIMITATIONS:
     This program is a brute force approach to loading an Image
file into AutoCAD. The file types which can be read at this time
are limited to IMG files. The program has been tested only with
files written by GEM Images software when run with an Everex 2200
scanner (8.5" x 11") and is not expected to work with all IMG files
as produced by other brands of software. DXB files produced are
large but can be reduced in size by directing IMG2DXB to skip rows
and columns of points.

     The program is directed at knowledgeable users and does not
contain error checking. If there is sufficient interest, this and
other "bells and whistles" will be added at a latter date. It
should also be noted that the program does not run instantly and
can take 20 minutes to convert a full size 8.5 x 11 (on a 16 Mhz,
386 with a 80387). Reducing the size to a minimum by "cutting out"
while in Images will keep times as small as possible. Remember that
about 8.4 million possible points are being processed.

NOTES ON USAGE:
     When started, IMG2DXB asks for the IMG file name (without
Extension) and for a skip value. The DXB file is created with the
same name as the IMG file. The skip value instructs IMG2DXB to pass
over that many pixels when converting a line of scanned pixels and
to skip that many lines when writing the DXB file. The effect is
to leave a matrix of points in the DXB file which are adequate to
trace over when loaded into AutoCAD. At the same time the DXB and
DWG file sizes can be dramatically reduced. For my purposes a skip
value of 5 is typically used as a starting point. While running,
the program prints the value of the scan line being processed so
that the user doesn't give up to quickly. The exception to this is
the occurrence of "repeat lines" which are not reported. Since
hundreds of repeat lines may occur some patience is helpful. 


     The DXB file is always written with the points located on the
layer "Scanpt" and this layer is created in the DWG file when the
file is imported.

AUTHOR'S COMMENTS:
     This program has been useful in importing details into
engineering drawings, in particular perspective views of light
fixtures, etc. When time permits, a program to convert FAX format
to AutoCAD and back is planned. 

Trademarks: AutoCAD-Autodesk; GEM Images-Digital Research; Everex
2200-Everex.