src/tiff/man/TIFFswab.3tiff

   1 .\"
   2 .\" Copyright (c) 1988-1997 Sam Leffler
   3 .\" Copyright (c) 1991-1997 Silicon Graphics, Inc.
   4 .\"
   5 .\" Permission to use, copy, modify, distribute, and sell this software and
   6 .\" its documentation for any purpose is hereby granted without fee, provided
   7 .\" that (i) the above copyright notices and this permission notice appear in
   8 .\" all copies of the software and related documentation, and (ii) the names of
   9 .\" Sam Leffler and Silicon Graphics may not be used in any advertising or
  10 .\" publicity relating to the software without the specific, prior written
  11 .\" permission of Sam Leffler and Silicon Graphics.
  12 .\"
  13 .\" THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
  14 .\" EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
  15 .\" WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  16 .\"
  17 .\" IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
  18 .\" ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
  19 .\" OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  20 .\" WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
  21 .\" LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  22 .\" OF THIS SOFTWARE.
  23 .\"
  24 .if n .po 0
  25 .TH SWAB 3TIFF "November 04, 2004" "libtiff"
  26 .SH NAME
  27 TIFFGetBitRevTable, TIFFReverseBits, TIFFSwabShort, TIFFSwabLong,
  28 TIFFSwabArrayOfShort, TIFFSwabArrayOfLong \- byte- and bit-swapping routines
  29 .SH SYNOPSIS
  30 .B "#include <tiffio.h>"
  31 .sp
  32 .BI "const unsigned char* TIFFGetBitRevTable(int " reversed ")"
  33 .br
  34 .BI "void TIFFReverseBits(u_char *" data ", unsigned long " nbytes ")"
  35 .br
  36 .BI "void TIFFSwabShort(uint16 *" data ")"
  37 .br
  38 .BI "void TIFFSwabLong(uint32 *" data ")"
  39 .br
  40 .BI "void TIFFSwabArrayOfShort(uint16 *" data ", unsigned long " nshorts ")"
  41 .br
  42 .BI "void TIFFSwabArrayOfLong(uint32 *" data ", unsigned long " nlongs ")"
  43 .SH DESCRIPTION
  44 The following routines are used by the library to swap
  45 16- and 32-bit data and to reverse the order of bits in bytes.
  46 .PP
  47 .IR TIFFSwabShort
  48 and
  49 .IR TIFFSwabLong
  50 swap the bytes in a single 16-bit and 32-bit item, respectively.
  51 .IR TIFFSwabArrayOfShort
  52 and
  53 .IR TIFFSwabArrayOfLong
  54 swap the bytes in an array of 16-bit and 32-bit items, respectively.
  55 .PP
  56 .IR TIFFReverseBits
  57 replaces each byte in
  58 .I data
  59 with the equivalent bit-reversed value. This operation is performed with a
  60 lookup table, which is returned using the
  61 .IR TIFFGetBitRevTable
  62 function.
  63 .I reversed
  64 parameter specifies which table should be returned. Supply
  65 .I 1
  66 if you want bit reversal table. Supply
  67 .I 0
  68 to get the table that do not reverse bit values. It is a lookup table that can
  69 be used as an
  70 .IR "identity function" ;
  71 i.e.
  72 .IR "TIFFNoBitRevTable[n] == n" .
  73 .SH DIAGNOSTICS
  74 None.
  75 .SH "SEE ALSO"
  76 .BR libtiff (3TIFF)
  77 .PP
  78 Libtiff library home page:
  79 .BR http://www.remotesensing.org/libtiff/