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NAME
    img2xes - Convert various types of image files into an XES-formatted
    hexadecimal data file

SYNOPSIS
    perl img2xes.pl [-width=*integer*] [-x=*integer*] [-height=*integer*]
    [-y=*integer*] [-depth=*string*] [-pixelwidth=*number*]
    [-memwidth=*number*] [-address=*integer*] [-ifile=*filename*]
    [-ofile=*filename*]

    perl img2xes.pl -help

DESCRIPTION
    img2xes converts image files into hexadecimal data files in the XES
    format. These hex files can be downloaded into the memory on an XS Board
    and displayed on a VGA monitor.

OPTIONS
    -width *integer*
        Sets width of the image (in pixels) that will be displayed on the
        VGA monitor. This is not necessarily the same as the width of the
        image in the image file. The default value is 800.

    -x *integer*
        Same as the -width option.

    -height *integer*
        Sets height of the image (in scanlines) that will be displayed on
        the VGA monitor. This is not necessarily the same as the height of
        the image in the image file. The default value is 600.

    -y *integer*
        Same as the -height option.

    -depth *string*
        Sets the depth of the image that will be displayed on the VGA
        monitor. This is not necessarily the same as the depth of the image
        in the image file. The depth is expressed as a string with the
        format *R+G+B* where R, G and B are the number of bits of resolution
        of the red, green and blue components of the colors displayed on the
        monitor. The default value is 3+2+3.

    -pixelwidth *integer*
        Sets the width (in bits) of a pixel. A pixel should be at least
        R+G+B bits wide. The default value is 8.

    -memwidth *integer*
        Sets the width (in bits) of the memory word that contains one or
        more pixels. The memory width should be at least as wide as the
        pixels. The default value is 16.

    -address *hex or octal address*
        Sets the starting address in memory for the hexadecimal image data.
        The image data proceeds upward from there. The address is
        interpreted as an octal number unless you precede it with an initial
        "0x" to indicate it is a hexadecimal address. The default value is
        0.

    -ifile *filename*
        Gives the name of the file containing the image data. The suffix of
        *filename* is used to determine the type of the image data as
        follows:

        .bmp Windows bitmap file.
        .png PNG file.
        .gif GIF file.
        .tif TIF file.
        .jpeg, .jpg JPEG file.
        .pgm Portable gray-map file.
        .ppm Portable pixel-map file.
        .pnm Portable any-map file.

        If -ifile is not used, then the image data is read from the standard
        input and is assumed to be in portable any-map format.

    -ofile *filename*
        Gives the name of the file where the XES-formatted hexadecimal data
        will be stored. If -ofile is not used, then the hexadecimal data is
        written to the standard output.

DIAGNOSTICS
    img2xes will abort if it does not recognize the suffix of the input
    image file or if the following contraint is not met:

        R+G+B <= pixel width <= memory width

EXAMPLES
    For the XSA Boards using the VGA generator circuit described in
    http://www.xess.com/appnotes/an-101204-vgagen.pdf, here are the commands
    to convert a JPEG file and produce an 800 x 600 display with pixel
    widths of 4, 8 and 16. (We will not explicitly set some options since
    the default settings will work in this case)

        perl img2xes.pl -depth 1+1+1 -pixelwidth 4 -ifile image.jpg -ofile
        image.xes

        perl img2xes.pl -depth 3+2+3 -pixelwidth 8 -ifile image.jpg -ofile
        image.xes

        perl img2xes.pl -depth 3+3+3 -pixelwidth 16 -ifile image.jpg -ofile
        image.xes

    To display a PNG file on a 1024 x 768 display, then do this:

        perl img2xes.pl -x 1024 -y 768 -depth 1+1+1 -pixelwidth 4 -ifile
        image.png -ofile image.xes

        perl img2xes.pl -x 1024 -y 768 -depth 3+2+3 -pixelwidth 8 -ifile
        image.png -ofile image.xes

        perl img2xes.pl -x 1024 -y 768 -depth 3+3+3 -pixelwidth 16 -ifile
        image.png -ofile image.xes

ENVIRONMENT
    img2xes requires a perl interpreter for its execution. You can get a
    free perl interpreter for Windows at www.activestate.com. You already
    have a perl interpreter if you are running linux, solaris or unix.

    img2xes requires the *netpbm* suite of image conversion programs in
    order to convert the various image file formats. You can get these from
    http://netpbm.sourceforge.net. Once installed, you need to place the
    *netpbm* directory in your path or store it directly in the
    $netpbm_bin_dir variable in img2xes.pl.

FILES
    None.

CAVEATS
    None.

BUGS
    Portable bitmap files (.pbm) are not handled, yet.

RESTRICTIONS
    None.

NOTES
    img2xes takes the red, green and blue component values of each pixel in
    the image file and does the following:

    1.  Each color component is truncated to the number of bits specified
        for that component by the -depth option.

    2.  The truncated color components are concatenated with the blue
        component in the least-significant bit positions, the red component
        in the most-significant bit positions, and the green component in
        between.

    3.  The concatenated components are placed into the least-significant
        bit positions of a pixel field whose width is set using the
        -pixelwidth option. Any unused bits in the upper portion of the
        pixel field are set to zero.

    4.  Pixel fields are concatenated until no more will fit into a memory
        word whose width is set using the -memwidth option. Pixel *N*
        occupies the least-significant bit positions while pixels *N+1*,
        *N+2*, ... occupy successively more-significant bit positions in the
        memory word.

    5.  The memory word is chopped into eight-bit bytes and output as
        two-digit hexadecimal values starting with the most-significant byte
        and proceeding to the least-significant byte.

SEE ALSO
    The most-current version of img2xes.pl can be found at
    http://wwww.xess.com/ho07000.html.

AUTHOR
    Dave Vanden Bout, X Engineering Software Systems Corp.

    Send bug reports to bugs@xess.com.

COPYRIGHT AND LICENSE
    Copyright 2004 by X Engineering Software Systems Corporation.

    This library is free software; you may redistribute it and/or modify it
    under the same terms as Perl itself.

HISTORY
    10/12/04 - Version 1.0