TIFFWRITESCANLINE(3tiff) LibTIFF TIFFWRITESCANLINE(3tiff)
NAME
TIFFWriteScanline - write a scanline to an open TIFF file
SYNOPSIS
#include <tiffio.h>
TIFFWriteScanline(3) *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() 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 TIFFErrorExtR() 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().
"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() 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() 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)
AUTHOR
LibTIFF contributors
COPYRIGHT
1988-2022, LibTIFF contributors
4.7 September 11, 2024 TIFFWRITESCANLINE(3tiff)
tiff 4.7.0 - Generated Thu Oct 3 14:41:37 CDT 2024