Current File : //usr/man/man3tiff/TIFFReadScanline.3tiff

'\" te
.TH TIFFReadScanline 3tiff "05 Apr 2004" "" ""
.SH "NAME"
TIFFReadScanline \- read and decode a scanline of data from an open TIFF file
.SH "SYNOPSIS"
.sp
.nf
\f(CW#include <tiffio\&.h>
int TIFFReadScanline(TIFF* tif, tdata_t buf, uint32 row,
tsample_t sample)\fR
.fi
.sp
.SH ""
.PP
Read the data for the specified row into the user-supplied data buffer\&.
.SH "EXTENDED DESCRIPTION"
.PP
The data is returned decompressed and in the native byte- and bit-ordering,
but is otherwise packed as described below\&. The buffer must be large enough
to hold an entire scanline of data\&. Applications should call the routine \fBTIFFScanlineSize\fR to find out the size in bytes of a scanline buffer\&.
The \fBrow\fR parameter is always used by \fBTIFFReadScanline\fR\&. The \fBsample\fR parameter is used only if data is
organized in separate planes (PlanarConfiguration=2)\&.
.PP
The library attempts to hide bit- and byte-ordering differences between
the image and the native machine by converting data to the native machine
order\&. Bit reversal is performed if the \fBFillOrder\fR tag is
opposite to the native machine bit order\&. 16- and 32-bit samples are automatically
byte-swapped if the file was written with a byte order opposite to the native
machine byte order\&.
.SS "Diagnostics"
.PP
All error messages are directed to the \fBTIFFError(3tiff)\fR
routine\&.
.sp
.ne 2
.mk
\fBCompression algorithm does not support random access\&.\fR
.in +24n
.rt
Data was requested in a non-sequential order from a
file that uses a compression algorithm and that has \fBRowsPerStrip\fR greater than one\&. That is, data in the image is 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 accessed
sequentially, or the file should be converted so that each strip is made up
of one row of data\&.
.sp
.sp 1
.in -24n
.SH ""
.PP
Returns -1 if an error was encountered\&. Otherwise, returns 1\&.
.SH ""
.PP
See \fBattributes\fR(5)
for descriptions of the following attributes:
.sp
.TS
tab() allbox;
cw(2.750000i)| cw(2.750000i)
lw(2.750000i)| lw(2.750000i).
ATTRIBUTE TYPEATTRIBUTE VALUE
Availabilityimage/library/libtiff
Interface stabilityUncommitted
.TE
.sp
.SH ""
.PP
\fBlibtiff\fR(3), \fBTIFFOpen\fR(3tiff), \fBTIFFReadEncodedStrip\fR(3tiff), \fBTIFFReadRawStrip\fR(3tiff)
.SH ""
.PP
In C++, the \fBsample\fR parameter defaults to 0\&.
.PP
Reading subsampled YCbCR data does not work correctly because:
.sp
.in +2
\(bu
.mk
.in +3
.rt
For PlanarConfiguration=2, the size of a scanline is not calculated
on a per-sample basis\&.
.sp
.in -3
\(bu
.mk
.in +3
.rt
For PlanarConfiguration=1, the library does not unpack the
block-interleaved samples\&.
.sp
.in -3
.in -2
.PP
Use the strip- and tile-based interfaces to read these formats\&.
.PP
This man page was originally written by Sam Leffler\&. Updated by Breda
McColgan, Sun Microsystems Inc\&., 2004\&.
...\" created by instant / solbook-to-man, Thu 20 Mar 2014, 02:30
...\" LSARC 2003/085 libtiff, libjpeg, and libpng