FBQUANT

NAME

SYNOPSIS

fbquant [ -c<numcolors> ] [ -<type> ] [ -m<map> ] < rgb-image > mapped-image

DESCRIPTION

Converts a 3 plane red-green-blue color image into a mapped color image. Uses Heckbert's adaptive partitioning color quantizing algorithm. It is strongly suggested that you make the number of colors used a power of 2, but not necessary for proper operation of FBM.

If you wish to requantize an image that is already mapped (for example, to reduce the number of colors), use "gray2clr -u" to unmap the image first. This unmapping step is also necessary to resize a color image using fbext(1).

You may specify a particular color map with the -m option. The argument is another mapped color image.

Note that even if you specify fewer than 256 colors, some output formats (SUN and FBM) will still use 8 bits to store each color index. The color map will be the specified length.  

OPTIONS

-c<num>

number of colors to use for dithering. The range is 8 to 256, and the default is 256.

-m<map>

colormap option, specifies that the colormap from the map image is to be used to quantize he input. Colormaps may be efficiently stored by extracting very small rectangles from another color image:

       % fbext 0 0 1 1 < image.clr > map.clr

which stores a 1 pixel image with the desired map.

-F

FBM, format (by default, the default). You are guaranteed not to lose information by specifying FBM as the default.

-G

GIF, Compuserve GIF format.

-I

IFF format, interleaved bitmaps (ILBM), used by Amigas. It is recommended that you use 16 or 32 colors, because the EL Arts code limits IFF files to 6 planes, and most Amiga software cannot handle more than 32 colors anyway.

-S

sun, Sun rasterfiles (not run length encoded).

EXAMPLE

To convert a 24 bit Sun rasterfile to an 8 bit mapped color rasterfile:

    % fbquant -S < foo.24bit > foo.clr

To convert a 24 bit Sun rasterfile to a 32 color Amiga image:

    % fbext -a1.2 -w320 < foo.24bit | 
      fbquant -I -c32 > foo.iff

To convert an FBM format RGB color image to a 16 color GIF image:
    % fbext -a1.2 -w320 < foo.24bit | 
      fbquant -G -c16 > foo.gif  

SEE ALSO

BUGS

HISTORY

25-Jun-90 Michael Mauldin at Carnegie Mellon University

Release 1.0 mlm@cs.cmu.edu

07-Mar-89 Michael L. Mauldin at Carnegie Mellon University

Beta release (version 0.9) mlm@cs.cmu.edu

Index

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

EXAMPLE

SEE ALSO

BUGS

HISTORY