User Commands                                       tiffmedian(1)



NAME
     tiffmedian - apply the median cut algorithm  to  data  in  a
     TIF file

SYNOPSIS
     tiffmedian [options] input.tif output.tif

DESCRIPTION
     tiffmedian applies the median cut algorithm to an RGB  image
     in input.tif, to generate a palette image that is written to
     output.tif.  The generated colormap  has,  by  default,  256
     entries.  The  image data is quantized by mapping each pixel
     to the closest color values in the colormap.

OPTIONS
     The following options are supported:

     -c              Specify a compression  scheme  to  use  when
                     writing image data:


                     -c lzw                  Lempel-Ziv and Welch
                                             algorithm.




                     -c none                 No compression.



                     -c packbits             PackBits compression
                                             algorithm.



                     -c zip                  Deflate  compression
                                             algorithm.


                     If no compression-related option  is  speci-
                     fied,  the  input-file compression algorithm
                     is used.


     -C              Specify the number of entries to use in  the
                     generated  colormap.  By  default,  all  256
                     entries or colors are used.







SunOS 5.11          Last change: 26 Mar 2004                    1






User Commands                                       tiffmedian(1)



     -f              Apply   Floyd-Steinberg   dithering   before
                     selecting a colormap entry.



     -r              Write data with a specified number  of  rows
                     per  strip.  By  default, the number of rows
                     per strip is selected so that each strip  is
                     approximately 8 kilobytes.



OPERANDS
     The following operands are supported:

     input.tif       The name of the input TIF file.



     output.tif      The name of the output file.



EXTENDED DESCRIPTION
     LZW compression can be specified together with  a  predictor
     value.  A  predictor  value of 2 causes each scanline of the
     output image to undergo horizontal differencing before being
     encoded.  A  predictor value of 1 forces each scanline to be
     encoded without differencing.

     LZW-specific options are specified  by  appending  a  colon-
     separated  list  to  the lzw option. For example, specify -c
     lzw:2 for LZW compression with horizontal differencing.

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Availability                 SUNWTiff                    
    
     Interface stability          Uncommitted                 
    


SEE ALSO
     Color Image Quantization  for  Frame  Buffer  Display,  Paul
     Heckbert, SIGRAPH proceedings, 1982, pp. 297-307.





SunOS 5.11          Last change: 26 Mar 2004                    2






User Commands                                       tiffmedian(1)



     pal2rgb(1), tiffinfo(1), tiffcp(1), tiffcmp(1), libtiff(3)

NOTES
     Updated by Breda McColgan, Sun Microsystems Inc., 2004.



















































SunOS 5.11          Last change: 26 Mar 2004                    3