140 lines
3.7 KiB
HTML
140 lines
3.7 KiB
HTML
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
|
||
|
|
<HTML><HEAD><TITLE>Manpage of TIFFReadScanline</TITLE>
|
||
|
|
</HEAD><BODY BGCOLOR=WHITE><FONT FACE="helvetica, sans, arial">
|
||
|
|
<H1>TIFFReadScanline</H1>
|
||
|
|
Section: Misc. Reference Manual Pages (3T)<BR>Updated: October 15, 1995<BR><A HREF="#index">Index</A>
|
||
|
|
<BR><A HREF="index.html">Return to Main Contents</A>
|
||
|
|
<HR>
|
||
|
|
|
||
|
|
<A NAME="lbAB"> </A>
|
||
|
|
<H2>NAME</H2>
|
||
|
|
|
||
|
|
TIFFReadScanline - read and decode a scanline of data from an open
|
||
|
|
<FONT SIZE="-1">TIFF</FONT>
|
||
|
|
file
|
||
|
|
<A NAME="lbAC"> </A>
|
||
|
|
<H2>SYNOPSIS</H2>
|
||
|
|
|
||
|
|
<B>#include <<A HREF="file:/usr/include/tiffio.h">tiffio.h</A>></B>
|
||
|
|
|
||
|
|
<BR>
|
||
|
|
|
||
|
|
<B>int TIFFReadScanline(TIFF* tif, tdata_t buf, uint32 row, tsample_t sample)</B>
|
||
|
|
|
||
|
|
<A NAME="lbAD"> </A>
|
||
|
|
<H2>DESCRIPTION</H2>
|
||
|
|
|
||
|
|
Read the data for the specified row into the (user supplied)
|
||
|
|
data buffer
|
||
|
|
<I>buf</I>.
|
||
|
|
|
||
|
|
The data are returned decompressed and, in the native byte-
|
||
|
|
and bit-ordering, but are otherwise packed (see further below).
|
||
|
|
The buffer must be large enough to hold an entire scanline of data.
|
||
|
|
Applications should call the routine
|
||
|
|
<I>TIFFScanlineSize</I>
|
||
|
|
|
||
|
|
to find out the size (in bytes) of a scanline buffer.
|
||
|
|
The
|
||
|
|
<I>row</I>
|
||
|
|
|
||
|
|
parameter is always used by
|
||
|
|
<I>TIFFReadScanline</I>;
|
||
|
|
|
||
|
|
the
|
||
|
|
<I>sample</I>
|
||
|
|
|
||
|
|
parameter is used only if data are organized in separate planes (<I>PlanarConfiguration</I>=2).
|
||
|
|
|
||
|
|
<A NAME="lbAE"> </A>
|
||
|
|
<H2>NOTES</H2>
|
||
|
|
|
||
|
|
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 done if the
|
||
|
|
<I>FillOrder</I>
|
||
|
|
|
||
|
|
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,
|
||
|
|
<P>
|
||
|
|
|
||
|
|
In C++ the
|
||
|
|
<I>sample</I>
|
||
|
|
|
||
|
|
parameter defaults to 0.
|
||
|
|
<A NAME="lbAF"> </A>
|
||
|
|
<H2>RETURN VALUES</H2>
|
||
|
|
|
||
|
|
<I>TIFFReadScanline</I>
|
||
|
|
|
||
|
|
returns -1 if it detects an error; otherwise 1 is returned.
|
||
|
|
<A NAME="lbAG"> </A>
|
||
|
|
<H2>DIAGNOSTICS</H2>
|
||
|
|
|
||
|
|
All error messages are directed to the
|
||
|
|
<I><A HREF="TIFFError.3t.html">TIFFError</A></I>(3T)
|
||
|
|
|
||
|
|
routine.
|
||
|
|
<P>
|
||
|
|
|
||
|
|
<B>Compression algorithm does not support random access</B>.
|
||
|
|
|
||
|
|
Data was requested in a non-sequential order from a file that
|
||
|
|
uses a compression algorithm and that has
|
||
|
|
<I>RowsPerStrip</I>
|
||
|
|
|
||
|
|
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.
|
||
|
|
<A NAME="lbAH"> </A>
|
||
|
|
<H2>BUGS</H2>
|
||
|
|
|
||
|
|
Reading subsampled YCbCR data does not work correctly
|
||
|
|
because, for
|
||
|
|
<I>PlanarConfiguration</I>=2
|
||
|
|
|
||
|
|
the size of a scanline is not calculated on a per-sample basis,
|
||
|
|
and for
|
||
|
|
<I>PlanarConfiguration</I>=1
|
||
|
|
|
||
|
|
the library does not unpack the block-interleaved samples; use
|
||
|
|
the strip- and tile-based interfaces to read these formats.
|
||
|
|
<A NAME="lbAI"> </A>
|
||
|
|
<H2>SEE ALSO</H2>
|
||
|
|
|
||
|
|
<I><A HREF="libtiff.3t.html">libtiff</A></I>(3T),
|
||
|
|
|
||
|
|
<I><A HREF="TIFFOpen.3t.html">TIFFOpen</A></I>(3T),
|
||
|
|
|
||
|
|
<I><A HREF="TIFFReadEncodedStrip.3t.html">TIFFReadEncodedStrip</A></I>(3T),
|
||
|
|
|
||
|
|
<I><A HREF="TIFFReadRawStrip.3t.html">TIFFReadRawStrip</A></I>(3T)
|
||
|
|
|
||
|
|
|
||
|
|
<HR>
|
||
|
|
<A NAME="index"> </A><H2>Index</H2>
|
||
|
|
<DL>
|
||
|
|
<DT><A HREF="#lbAB">NAME</A><DD>
|
||
|
|
<DT><A HREF="#lbAC">SYNOPSIS</A><DD>
|
||
|
|
<DT><A HREF="#lbAD">DESCRIPTION</A><DD>
|
||
|
|
<DT><A HREF="#lbAE">NOTES</A><DD>
|
||
|
|
<DT><A HREF="#lbAF">RETURN VALUES</A><DD>
|
||
|
|
<DT><A HREF="#lbAG">DIAGNOSTICS</A><DD>
|
||
|
|
<DT><A HREF="#lbAH">BUGS</A><DD>
|
||
|
|
<DT><A HREF="#lbAI">SEE ALSO</A><DD>
|
||
|
|
</DL>
|
||
|
|
<HR>
|
||
|
|
This document was created by
|
||
|
|
<A HREF="index.html">man2html</A>,
|
||
|
|
using the manual pages.<BR>
|
||
|
|
Time: 01:31:38 GMT, November 23, 1999
|
||
|
|
</BODY>
|
||
|
|
</HTML>
|