                                  [JS_DDB2JPEG]
                          (Version 1.0, 28 May 1998)

Program Description:

  Allows the user to convert a Jumpstart Collection Dynamic DataBase 
  (DDB) complex stripmap image to 8-bit JFIF (JPEG) format.



Program Usage:

     js_ddb2jpeg -i <infile> -o <outfile> -e -h -q [qf] -t [0-7]

       Options: -e       = Auto-contrast enhance output [Def: none]
                -h       = Dump Phoenix (ASCII) header [Def: none]
                -q [qf]  = Compression quality factor (5-95, Def:75)
                -t [0-7] = Convert specific tile of data
                           (ONLY for images whose height >= 1024)

Description of Arguments:

     <infile> : Input (complex) Jumpstart DDB stripmap image filename
     <outfile>: Output JPEG image filename
     -e       : Optional auto-enhancement switch
     -h       : Optional Phoenix header dump switch
     -q [qf]  : Optional compression factor switch
     -t [0-7] : Optional single tile conversion switch

Files Necessary to Compile:

     * Include : jpeglib.h   (Contains JPEG file defs.)
     * Library : JPEG libjpeg library (OS-dependent)
     * Source  : js_ddb2jpeg.c
                 read_switch.c
     * Make    : js_ddb2jpeg.mk (optional)


Compiling and Linking Code:

   You can compile js_ddb2jpeg either from the command line or by using the 
   included makefile (note: .mk file).

   a) Command line Method:

        % gcc -c read_switch.c [enter]
        % gcc -o js_ddb2jpeg js_ddb2jpeg.c read_switch.o libjpegSunOS.a -lm [enter]
      
      NOTE: You can use other C compilers. Edit .mk file as necessary. You also
            may need to re-make JPEG library if using non-Sun machine.

   b) Using the Makefile [js_ddb2jpeg.mk]:

      Perform the following steps:

        % make -f js_ddb2jpeg.mk        [Creates executable: js_ddb2jpeg]
        % make -f js_ddb2jpeg.mk clean  [Deletes object code            ]

