TIFFReadRawTile.3tiff man page
TIFFReadRawTile — return an undecoded tile of data from an open TIFF file
tsize_t TIFFReadRawTile(TIFF *tif, ttile_t tile, tdata_t buf, tsize_t size)
Read the contents of the specified tile into the (user supplied) data buffer. Note that the value of tile is a “raw tile number.” That is, the caller must take into account whether or not the data is 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 typically be at least as large as the value returned by TIFFTileSize.
The actual number of bytes of data that were placed in buf is returned; TIFFReadEncodedTile returns -1 if an error was encountered.
All error messages are directed to the TIFFError(3TIFF) routine.
TIFFOpen(3TIFF), TIFFReadEncodedTile(3TIFF), TIFFReadTile(3TIFF), TIFFTileSize(3TIFF), libtiff(3TIFF)
Libtiff library home page: http://www.simplesystems.org/libtiff/