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man pages section 5: File Formats

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Updated: Thursday, June 13, 2019
 
 

rasterfile (5)

Name

rasterfile - Sun's file format for raster images

Synopsis

#include <pixrect/rasterfile.h>

Description

rasterfile(5)                 File Formats Manual                rasterfile(5)



NAME
       rasterfile - Sun's file format for raster images

SYNOPSIS
       #include <pixrect/rasterfile.h>

DESCRIPTION
       A  rasterfile  is composed of three parts: first, a header containing 8
       integers; second, a (possibly empty) set of colormap values; and third,
       the  pixel  image, stored a line at a time, in increasing y order.  The
       image is layed out in the file as in a memory pixrect.   Each  line  of
       the image is rounded up to the nearest 16 bits.

       The header is defined by the following structure:

              struct rasterfile {
                   int  ras_magic;
                   int  ras_width;
                   int  ras_height;
                   int  ras_depth;
                   int  ras_length;
                   int  ras_type;
                   int  ras_maptype;
                   int  ras_maplength;
              };

       The ras_magic field always contains the following constant:

              #define   RAS_MAGIC 0x59a66a95

       The  ras_width,  ras_height,  and  ras_depth fields contain the image's
       width and height in pixels, and its depth in bits  per  pixel,  respec-
       tively.   The  depth  is either 1 or 8, corresponding to standard frame
       buffer depths.  The ras_length field contains the length  in  bytes  of
       the image data.  For an unencoded image, this number is computable from
       the ras_width, ras_height, and ras_depth fields,  but  for  an  encoded
       image  it  must  be  explicitly stored in order to be available without
       decoding the image itself.  Note: the length of the header and  of  the
       (possibly  empty)  colormap values are not included in the value of the
       ras_length field; it is only the image  data  length.   For  historical
       reasons,  files  of type RT_OLD will usually have a 0 in the ras_length
       field, and software expecting to encounter such files  should  be  pre-
       pared  to compute the actual image data length if needed.  The ras_map-
       type and ras_maplength fields contain the type and length in  bytes  of
       the  colormap values, respectively.  If ras_maptype is not RMT_NONE and
       the  ras_maplength  is  not  0,  then  the  colormap  values  are   the
       ras_maplength  bytes  immediately  after  the header.  These values are
       either  uninterpreted  bytes  (usually  with  the  ras_maptype  set  to
       RMT_RAW) or the equal length red, green and blue vectors, in that order
       (when the ras_maptype is  RMT_EQUAL_RGB).   In  the  latter  case,  the
       ras_maplength  must  be three times the size in bytes of any one of the
       vectors.



ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+-----------------------+
       |ATTRIBUTE TYPE |   ATTRIBUTE VALUE     |
       +---------------+-----------------------+
       |Availability   | x11/header/rasterfile |
       +---------------+-----------------------+
       |Stability      | Volatile              |
       +---------------+-----------------------+
                                 29 March 1994                   rasterfile(5)