TIFFReadTile(3)
read and decode a tile of data from an open
SYNOPSIS
#include <tiffio.h>
tsize_t TIFFReadTile(TIFF *tif, tdata_t buf, uint32 x, uint32 y, uint32 z, tsample_t sample)
DESCRIPTION
Return the data for the tile
containing
the specified coordinates. The data placed in
buf
are returned decompressed and, typically, in the native byte- and
bit-ordering, but are otherwise packed (see further below). The buffer must be
large enough to hold an entire tile of data. Applications should call the
routine
TIFFTileSize
to find out the size (in bytes) of a tile buffer. The
x
and
y
parameters are always used by
TIFFReadTile.
The
z
parameter is used if the image is deeper than 1 slice (ImageDepth>1).
The
sample
parameter is used only if data are organized in separate planes (PlanarConfiguration=2).
NOTES
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
TIFFReadTile
returns -1 if it detects an error; otherwise the number of bytes in the
decoded tile is returned.
DIAGNOSTICS
All error messages are directed to the
TIFFError(3TIFF)
routine.