NAME

       TIFFWriteScanline - write a scanline to an open TIFF file

SYNOPSIS

       #include <tiffio.h>

       int TIFFWriteScanline(TIFF *tif, tdata_t buf, uint32_t 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/

libtiff                                         December 16, 1991                       TIFFWriteScanline(3TIFF)