NAME¶
TIFFReadEncodedTile - read and decode a tile of data from an open
TIFF file
SYNOPSIS¶
#include <tiffio.h>
int TIFFReadEncodedTile(TIFF *tif, ttile_t tile,
tdata_t buf, tsize_t size)
DESCRIPTION¶
Read the specified tile of data and place up to
size bytes of
decompressed information in the (user supplied) data buffer.
NOTES¶
The value of
tile is a ``raw tile number.'' That is, the caller must take
into account whether or not the data are organized in separate planes
(
PlanarConfiguration=2).
TIFFComputeTile automatically does this
when converting an (x,y,z,sample) coordinate quadruple to a tile number. To
read a full tile of data the data buffer should be at least as large as the
value returned by
TIFFTileSize.
The library attempts to hide bit- and byte-ordering differences between the
image and the native machine by converting data to the native machine order.
Bit reversal is done if the
FillOrder tag is opposite to the native
machine bit order. 16- and 32-bit samples are automatically byte-swapped if
the file was written with a byte order opposite to the native machine byte
order,
RETURN VALUES¶
The actual number of bytes of data that were placed in
buf is returned;
TIFFReadEncodedTile returns -1 if an error was encountered.
DIAGNOSTICS¶
All error messages are directed to the
TIFFError(3TIFF) routine.
SEE ALSO¶
TIFFOpen(3TIFF),
TIFFReadRawTile(3TIFF),
TIFFReadTile(3TIFF),
libtiff(3TIFF)
Libtiff library home page:
http://www.remotesensing.org/libtiff/