TIFFREADDIRECTORY(3tiff) LibTIFF TIFFREADDIRECTORY(3tiff)
NAME
TIFFReadDirectory - get the contents of the next directory in an open
TIFF file
SYNOPSIS
#include <tiffio.h>
int TIFFReadDirectory(TIFF *tif)
DESCRIPTION
Read the next directory in the specified file and make it the current
directory. Applications only need to call TIFFReadDirectory() to read
multiple subfiles in a single TIFF file—(the first directory in a file
is automatically read when TIFFOpen() is called.
NOTES
If the library is compiled with STRIPCHOP_SUPPORT enabled, then images
that have a single uncompressed strip or tile of data are automatically
treated as if they were made up of multiple strips or tiles of approxi-
mately 8 kilobytes each. This operation is done only in-memory; it does
not alter the contents of the file. However, the construction of the
"chopped strips" is visible to the application through the number of
strips [tiles] returned by TIFFNumberOfStrips() [TIFFNumberOfTiles()].
RETURN VALUES
If the next directory was successfully read, 1 is returned. Otherwise,
0 is returned if an error was encountered, or if there are no more di-
rectories to be read.
DIAGNOSTICS
All error messages are directed to the TIFFErrorExtR() routine. Like-
wise, warning messages are directed to the TIFFWarningExtR() routine.
Seek error accessing TIFF directory:
An error occurred while positioning to the location of the direc-
tory.
Wrong data type %d for field "%s":
The tag entry in the directory had an incorrect data type. For ex-
ample, an ImageDescription tag with a SHORT data type.
TIFF directory is missing required "%s" field:
The specified tag is required to be present by the TIFF 5.0 specifi-
cation, but is missing. The directory is (usually) unusable.
%s: Rational with zero denominator:
A directory tag has a RATIONAL value whose denominator is zero.
Incorrect count %d for field "%s" (%lu, expecting %lu); tag ignored:
The specified tag's count field is bad. For example, a count other
than 1 for a SubFileType tag.
Cannot handle different per-sample values for field "%s":
The tag has SamplesPerPixel values and they are not all the same;
e.g. BitsPerSample. The library is unable to handle images of this
sort.
Count mismatch for field "%s"; expecting %d, got %d:
The count field in a tag does not agree with the number expected by
the library. This should never happen, so if it does, the library
refuses to read the directory.
Invalid TIFF directory; tags are not sorted in ascending order:
The directory tags are not properly sorted as specified in the TIFF
5.0 specification. This error is not fatal.
Ignoring unknown field with tag %d (0x%x):
An unknown tag was encountered in the directory; the library ignores
all such tags.
TIFF directory is missing required "ImageLength" field:
The image violates the specification by not having a necessary
field. There is no way for the library to recover from this error.
TIFF directory is missing required "PlanarConfig" field:
The image violates the specification by not having a necessary
field. There is no way for the library to recover from this error.
TIFF directory is missing required "StripOffsets" field:
The image has multiple strips, but is missing the tag that specifies
the file offset to each strip of data. There is no way for the li-
brary to recover from this error.
TIFF directory is missing required "TileOffsets" field:
The image has multiple tiles, but is missing the tag that specifies
the file offset to each tile of data. There is no way for the li-
brary to recover from this error.
TIFF directory is missing required "StripByteCounts" field:
The image has multiple strips, but is missing the tag that specifies
the size of each strip of data. There is no way for the library to
recover from this error.
TIFF directory is missing required "StripByteCounts" field, calculating
from imagelength:
The image violates the specification by not having a necessary
field. However, when the image is comprised of only one strip or
tile, the library will estimate the missing value based on the file
size.
Bogus "StripByteCounts" field, ignoring and calculating from image-
length:
Certain vendors violate the specification by writing zero for the
StripByteCounts tag when they want to leave the value unspecified.
If the image has a single strip, the library will estimate the miss-
ing value based on the file size.
SEE ALSO
TIFFOpen (3tiff), TIFFCreateDirectory (3tiff), TIFFCustomDirectory
(3tiff), TIFFquery (3tiff), TIFFWriteDirectory (3tiff),
TIFFSetDirectory (3tiff), libtiff (3tiff)
AUTHOR
LibTIFF contributors
COPYRIGHT
1988-2023, LibTIFF contributors
4.5 Nov 23, 2023 TIFFREADDIRECTORY(3tiff)
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