TIFFOpen

Section: Misc. Reference Manual Pages (3T)
Updated: February 14, 1992
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NAME

TIFFOpen, TIFFFdOpen - open a TIFF file for reading or writing

SYNOPSIS

#include <tiffio.h>
TIFF* TIFFOpen(const char* filename, const char* mode)

TIFF* TIFFFdOpen(const int fd, const char* filename, const char* mode)

DESCRIPTION

TIFFOpen() opens a TIFF file whose name is filename and returns a handle to be used in subsequent calls to routines in libtiff. If the open operation fails, then a null handle is returned. The mode parameter specifies if the file is to be opened for reading (``r''), writing (``w''), or appending (``a''). When a file is opened for appending, existing data will not be touched; instead new data will be written as additional subfiles. If an existing file is opened for writing, all previous data is overwritten.

If a file is opened for reading, the first TIFF directory in the file is automatically read (also see TIFFSetDirectory(3T) for reading directories other than the first). If a file is opened for writing or appending, a default directory is automatically created for writing subsequent data. This directory has all the default values specified in TIFF Revision 6.0: BitsPerSample=1, ThreshHolding=bilevel art scan, FillOrder=1 (most significant bit of each data byte is filled first), Orientation=1 (the 0th row represents the visual top of the image, and the 0th column represents the visual left hand side), SamplesPerPixel=1, RowsPerStrip=infinity, ResolutionUnit=2 (inches), and Compression=1 (no compression). To alter these values, or to define values for additional fields, TIFFSetField(3T) must be used.

It is not possible to append data to a file that has a byte ordering opposite to the native byte ordering of a machine. That is, for example, the library will not allow a file with little-endian byte ordering to be appended to on a machine that has a native big-endian byte ordering.

TIFFFdOpen() is like TIFFOpen() except that it opens a TIFF file given an open file descriptor fd. The file's name and mode must reflect that of the open descriptor. The object associated with the file descriptor must support random access.

DIAGNOSTICS

All error messages are directed to the TIFFError(3T) routine. Likewise, warning messages are directed to the TIFFWarning(3T) routine.

"%s": Bad mode. The specified mode parameter was not one of ``r'' (read), ``w'' (write), or ``a'' (append).

%s: Cannot open. TIFFOpen() was unable to open the specified filename for read/writing.

Cannot read TIFF header. An error occurred while attempting to read the header information.

Error writing TIFF header. An error occurred while writing the default header information for a new file.

Not a TIFF file, bad magic number %d (0x%x). The magic number in the header was not (hex) 0x4d4d or (hex) 0x4949.

Not a TIFF file, bad version number %d (0x%x). The version field in the header was not 42 (decimal).

Cannot append to file that has opposite byte ordering. A file with a byte ordering opposite to the native byte ordering of the current machine was opened for appending (``a''). This is a limitation of the library.