tiffreadscanline(3tiff) [hpux man page]
TIFFReadScanline(3tiff) Introduction to Library Functions TIFFReadScanline(3tiff) NAME
TIFFReadScanline - read and decode a scanline of data from an open TIFF file SYNOPSIS
#include <tiffio.h> int TIFFReadScanline(TIFF* tif, tdata_t buf, uint32 row, tsample_t sample) DESCRIPTION
Read the data for the specified row into the user-supplied data buffer. EXTENDED DESCRIPTION
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 TIFFScanlineSize to find out the size in bytes of a scanline buffer. The row parameter is always used by TIFFReadScanline. The sample parameter is used only if data is organized in separate planes (PlanarConfiguration=2). 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 FillOrder tag is opposite to the native machine bit order. 16- and 32-bit samples are auto- matically byte-swapped if the file was written with a byte order opposite to the native machine byte order. Diagnostics All error messages are directed to the TIFFError(3tiff) routine. Compression algorithm doDataowasurequesteddin acnon-sequential order from a file that uses a compression algorithm and that has RowsPer- Strip 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. RETURN VALUES
Returns -1 if an error was encountered. Otherwise, returns 1. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWTiff | +-----------------------------+-----------------------------+ |Interface stability |External | +-----------------------------+-----------------------------+ SEE ALSO
libtiff(3), TIFFOpen(3tiff), TIFFReadEncodedStrip(3tiff), TIFFReadRawStrip(3tiff) NOTES
In C++, the sample parameter defaults to 0. Reading subsampled YCbCR data does not work correctly because: o For PlanarConfiguration=2, the size of a scanline is not calculated on a per-sample basis. o For PlanarConfiguration=1, the library does not unpack the block-interleaved samples. Use the strip- and tile-based interfaces to read these formats. This man page was originally written by Sam Leffler. Updated by Breda McColgan, Sun Microsystems Inc., 2004. SunOS 5.10 05 Apr 2004 TIFFReadScanline(3tiff)
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TIFFReadScanline(3tiff) Introduction to Library Functions TIFFReadScanline(3tiff) NAME
TIFFReadScanline - read and decode a scanline of data from an open TIFF file SYNOPSIS
#include <tiffio.h> int TIFFReadScanline(TIFF* tif, tdata_t buf, uint32 row, tsample_t sample) DESCRIPTION
Read the data for the specified row into the user-supplied data buffer. EXTENDED DESCRIPTION
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 TIFFScanlineSize to find out the size in bytes of a scanline buffer. The row parameter is always used by TIFFReadScanline. The sample parameter is used only if data is organized in separate planes (PlanarConfiguration=2). 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 FillOrder tag is opposite to the native machine bit order. 16- and 32-bit samples are auto- matically byte-swapped if the file was written with a byte order opposite to the native machine byte order. Diagnostics All error messages are directed to the TIFFError(3tiff) routine. Compression algorithm doDataowasurequesteddin acnon-sequential order from a file that uses a compression algorithm and that has RowsPer- Strip 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. RETURN VALUES
Returns -1 if an error was encountered. Otherwise, returns 1. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWTiff | +-----------------------------+-----------------------------+ |Interface stability |External | +-----------------------------+-----------------------------+ SEE ALSO
libtiff(3), TIFFOpen(3tiff), TIFFReadEncodedStrip(3tiff), TIFFReadRawStrip(3tiff) NOTES
In C++, the sample parameter defaults to 0. Reading subsampled YCbCR data does not work correctly because: o For PlanarConfiguration=2, the size of a scanline is not calculated on a per-sample basis. o For PlanarConfiguration=1, the library does not unpack the block-interleaved samples. Use the strip- and tile-based interfaces to read these formats. This man page was originally written by Sam Leffler. Updated by Breda McColgan, Sun Microsystems Inc., 2004. SunOS 5.10 05 Apr 2004 TIFFReadScanline(3tiff)