FreeBSD manual

download PDF document: TIFFReadTile.3.pdf

TIFFReadTile(3TIFF) TIFFReadTile(3TIFF) NAME TIFFReadTile - read and decode a tile of data from an open TIFF file SYNOPSIS #include <tiffio.h> tsize_t TIFFReadTile(TIFF *tif, tdata_t buf, uint32_t x, uint32_t y, uint32_t 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. SEE ALSO TIFFCheckTile(3TIFF), TIFFComputeTile(3TIFF), TIFFOpen(3TIFF), TIFFReadEncodedTile(3TIFF), TIFFReadRawTile(3TIFF), libtiff(3TIFF) Libtiff library home page: http://www.simplesystems.org/libtiff/ libtiff December 16, 1991 TIFFReadTile(3TIFF)