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.simplesystems.org/libtiff/