TIFFWriteScanline
Section: Misc. Reference Manual Pages (3T)
Updated: December 16, 1991
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NAME
TIFFWriteScanline - write a scanline to an open
TIFF
file
SYNOPSIS
#include <tiffio.h>
int TIFFWriteScanline(TIFF* tif, u_char* buf, u_int row, u_int 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).
TIFFWriteScanline
returns -1 if it immediately detects an error
and 1 for a successful write.
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 attempts to hide bit- and byte-ordering differences
between the image and the native machine by converting data
from the native machine order.
Bit reversal is always done if the
FillOrder
tag is opposite to the native machine bit order.
Byte swapping of 16- and 32-bit samples is automatically
done when
Compression=1
(``no compression''), but otherwise is left to the
compression algorithms (which should generate compressed
data in the native byte ordering of the machine).
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(3T)
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.
DIAGNOSTICS
All error messages are directed to the
TIFFError(3T)
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(3T).
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(3T)
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(3T)
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
intro(3T),
TIFFOpen(3T),
TIFFWriteEncodedStrip(3T),
TIFFWriteRawStrip(3T)
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- NOTES
-
- DIAGNOSTICS
-
- BUGS
-
- SEE ALSO
-
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