TIFFWriteScanline(3TIFF)                              TIFFWriteScanline(3TIFF)



NAME
       TIFFWriteScanline - write a scanline to an open TIFF file

SYNOPSIS
       #include <tiffio.h>

       int TIFFWriteScanline(TIFF *tif, tdata_t buf, uint32 row, tsample_t
       sample)

DESCRIPTION
       Write data to a file at the specified row. The sample parameter is used
       only if data are organized in separate planes (PlanarConfiguration=2).
       The data are assumed to be uncompressed and in the native bit- and
       byte-order of the host machine. The data written to the file is
       compressed according to the compression scheme of the current TIFF
       directory (see further below). If the current scanline is past the end
       of the current subfile, the ImageLength field is automatically
       increased to include the scanline (except for PlanarConfiguration=2,
       where the ImageLength cannot be changed once the first data are
       written). If the ImageLength is increased, the StripOffsets and
       StripByteCounts fields are similarly enlarged to reflect data written
       past the previous end of image.

NOTES
       The library writes encoded data using the native machine byte order.
       Correctly implemented TIFF readers are expected to do any necessary
       byte-swapping to correctly process image data with BitsPerSample
       greater than 8. The library attempts to hide bit-ordering differences
       between the image and the native machine by converting data from the
       native machine order.

       In C++ the sample parameter defaults to 0.

       Once data are written to a file for the current directory, the values
       of certain tags may not be altered; see TIFFSetField(3TIFF) for more
       information.

       It is not possible to write scanlines to a file that uses a tiled
       organization.  The routine TIFFIsTiled can be used to determine if the
       file is organized as tiles or strips.

RETURN VALUES
       TIFFWriteScanline returns -1 if it immediately detects an error and 1
       for a successful write.

DIAGNOSTICS
       All error messages are directed to the TIFFError(3TIFF) routine.

       %s: File not open for writing .  The file was opened for reading, not
       writing.

       Can not write scanlines to a tiled image.  An attempt was made to write
       a scanline to a tiled image. The image is assumed to be organized in
       tiles because the TileWidth and TileLength tags have been set with
       TIFFSetField(3TIFF).

       Compression algorithm does not support random access.  Data was written
       in a non-sequential order to a file that uses a compression algorithm
       and that has RowsPerStrip greater than one. That is, data in the image
       is to be stored in a compressed form, and with multiple rows packed
       into a strip. In this case, the library does not support random access
       to the data. The data should either be written as entire strips,
       sequentially by rows, or the value of RowsPerStrip should be set to
       one.

       %s: Must set "ImageWidth" before writing data.  The image's width has
       not be set before the first write.  See TIFFSetField(3TIFF) for
       information on how to do this.

       %s: Must set "PlanarConfiguration" before writing data.  The
       organization of data has not be defined before the first write.  See
       TIFFSetField(3TIFF) for information on how to do this.

       Can not change "ImageLength" when using separate planes. Separate image
       planes are being used (PlanarConfiguration=2), but the number of rows
       has not been specified before the first write. The library supports the
       dynamic growth of an image only when data are organized in a contiguous
       manner (PlanarConfiguration=1).

       %d: Sample out of range, max %d.  The sample parameter was greater than
       the value of the SamplesPerPixel tag.

       %s: No space for strip arrays .  There was not enough space for the
       arrays that hold strip offsets and byte counts.

BUGS
       Writing subsampled YCbCR data does not work correctly because, for
       PlanarConfiguration=2 the size of a scanline is not calculated on a
       per-sample basis, and for PlanarConfiguration=1 the library does not
       pack the block-interleaved samples.

SEE ALSO
       TIFFOpen(3TIFF), TIFFWriteEncodedStrip(3TIFF),
       TIFFWriteRawStrip(3TIFF), libtiff(3TIFF)

       Libtiff library home page: http://www.remotesensing.org/libtiff/



libtiff                        December 16, 1991      TIFFWriteScanline(3TIFF)
