NAME
      float_to_exp - Convert floating point values
           into "exponential" pixels.

 SYNOPSIS
      #include <rle.h>

      float_to_exp( count, floats, pixels )
      int count;
      float * floats;
      rle_pixel * pixels;

 DESCRIPTION
      The function float_to_exp converts count
      floating point numbers (pointed to by floats)
      into count+1 bytes (pointed to by pixels)
      using an "exponential" format.  This format
      generates count pixels as eight bit
      "mantissa" values, and another byte
      containing a common exponent for all of the
      data values.  This format has a wider dynamic
      range of values with little extra overhead.
      The inverse mapping is
           float expnt, flt_val;
           rle_pixel exponent, val;
           expnt = ldexp( 1/256.0, (int)exponent - 127 );
           flt_val = (float)val * expnt;

      Files containing exponential data may be
      converted into displayable images using the
      unexp(1) command. Unexp should be used before
      using any tools that perform arithmetic on
      pixel values, or displaying the image.  Unexp
      expects files containing exponential data to
      have an "exponential_data" picture comment.

 SEE ALSO
      unexp(1), rle_putcom(3), librle(3), RLE(5).

 AUTHOR
      John W. Peterson, based on code by Spencer
      Thomas.
      University of Utah







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