GIF-FB(1)

NAME
gif-fb - display GIF file on frame buffer

SYNOPSIS

gif-fb [-F frame_buffer_file] [-c] [-i image_number] [-o] [-v] [-z] [GIF_file_name]

DESCRIPTION

gif-fb displays on a frame buffer the images described by a CompuServe GIF (Graphics Interchange Format) file.

  Options

-F frame_buffer_name
    Outputs to the specified frame buffer instead of the one specified by the FB_FILE environment variable (or the default frame buffer, if FB_FILE is not set). The frame buffer size requested will be the same as the input GIF screen size. The actual size obtained depends on details of the specific frame buffer.

-c
    Uses all 8 bits per channel for color maps supplied in the GIF file, overriding the color resolution specified in the GIF file. (While technically a violation of the GIF standard, apparently some GIF implementations assume this interpretation.)

-i
    Displays just the specified image (starting counting with 1), rather than displaying all images as the GIF specification requires.

-o
    (overlay) Skips the initial clearing of the frame buffer to the background color specified in the GIF file.

-v
    (verbose) Also prints information about the GIF images on the standard error output.

-z
    (zoom) Uses the zoom capability of the current framebuffer to make the image as large as possible on the screen while preserving a square aspect ratio to the pixels. This means that the zoom factor in X and Y will be equal to the smaller of the two possible zooms.

GIF_file_name
    Specifies the GIF input file to be translated, rather than reading the file from the standard input.

DISCUSSION

The GIF standard is far from an ideal specification for frame buffer images, but it has been widely accepted in the personal computer arena, and consequently there are a large number of images stored in GIF format on bulletin-board systems and other information services. Since most personal computer systems have GIF translators available for them, gif-fb provides a means of converting most images from such systems into a form suitable for processing with other BRL-CAD utilities.

Notice that multiple images within a single GIF file can achieve animation effects.

EXAMPLE

The following is a typical invocation:

    gif-fb image.gif

SEE ALSO

A Standard Defining a Mechanism for the Storage and Transmission of Raster-Based Graphics Information, June 15, 1987 (CompuServe Incorporated). libfb(3)

DIAGNOSTICS

Error messages are intended to be self-explanatory.

AUTHOR

Douglas A. Gwyn, BRL/VLD-VMB

COPYRIGHT

This software is Copyright (c) 1989-2021 by the United States Government as represented by U.S. Army Research Laboratory.

BUG REPORTS

Reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org