src/tiff/tools/rasterfile.h

   1 /* $Header: /cvs/libtiff/tools/rasterfile.h,v 1.3 2003/11/12 19:14:33 dron Exp $ */
   2
   3 /*
   4  * Description of header for files containing raster images
   5  */
   6 struct rasterfile {
   7         char    ras_magic[4];           /* magic number */
   8         long    ras_width;              /* width (pixels) of image */
   9         long    ras_height;             /* height (pixels) of image */
  10         long    ras_depth;              /* depth (1, 8, or 24 bits) of pixel */
  11         long    ras_length;             /* length (bytes) of image */
  12         long    ras_type;               /* type of file; see RT_* below */
  13         long    ras_maptype;            /* type of colormap; see RMT_* below */
  14         long    ras_maplength;          /* length (bytes) of following map */
  15         /* color map follows for ras_maplength bytes, followed by image */
  16 };
  17 #define RAS_MAGIC       "\x59\xa6\x6a\x95"
  18 #define RAS_MAGIC_INV   "\x95\x6a\xa6\x59"
  19
  20         /* Sun supported ras_type's */
  21 #define RT_OLD          0       /* Raw pixrect image in 68000 byte order */
  22 #define RT_STANDARD     1       /* Raw pixrect image in 68000 byte order */
  23 #define RT_BYTE_ENCODED 2       /* Run-length compression of bytes */
  24 #define RT_EXPERIMENTAL 0xffff  /* Reserved for testing */
  25
  26         /* Sun registered ras_maptype's */
  27 #define RMT_RAW         2
  28         /* Sun supported ras_maptype's */
  29 #define RMT_NONE        0       /* ras_maplength is expected to be 0 */
  30 #define RMT_EQUAL_RGB   1       /* red[ras_maplength/3],green[],blue[] */
  31
  32 /*
  33  * NOTES:
  34  *      Each line of the image is rounded out to a multiple of 16 bits.
  35  *   This corresponds to the rounding convention used by the memory pixrect
  36  *   package (/usr/include/pixrect/memvar.h) of the SunWindows system.
  37  *      The ras_encoding field (always set to 0 by Sun's supported software)
  38  *   was renamed to ras_length in release 2.0.  As a result, rasterfiles
  39  *   of type 0 generated by the old software claim to have 0 length; for
  40  *   compatibility, code reading rasterfiles must be prepared to compute the
  41  *   true length from the width, height, and depth fields.
  42  */