<meta content="groff -Thtml, see www.gnu.org" name="generator">

<meta content="text/css" name="Content-Style">

<title>TIFFReadDirectory</title>

TIFFReadDirectory

NAME

SYNOPSIS

DESCRIPTION

NOTES

RETURN VALUES

DIAGNOSTICS

SEE ALSO

NAME

       cols="2" cellspacing="0" cellpadding="0">

<big>TIFFReadDirectory − get the contents of the</big>

next directory in an open TIFF <big>file</big>

SYNOPSIS

       cols="2" cellspacing="0" cellpadding="0">

<big>#include <tiffio.h></big>

<big>int TIFFReadDirectory(TIFF</big>

*tif)

DESCRIPTION

       cols="2" cellspacing="0" cellpadding="0">

<big>Read the next directory in the specified file and</big>

make it the current directory. Applications only need to

call TIFFReadDirectory to read multiple subfiles in a

single TIFF <big>file— the first directory in a</big>

file is automatically read when TIFFOpen is

called.

NOTES

       cols="2" cellspacing="0" cellpadding="0">

<big>If the library is compiled with</big>

STRIPCHOP_SUPPORT <big>enabled, then images that have a</big>

single uncompressed strip or tile of data are automatically

treated as if they were made up of multiple strips or tiles

of approximately 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

       cols="2" cellspacing="0" cellpadding="0">

<big>If the next directory was successfully read, 1 is</big>

returned. Otherwise, 0 is returned if an error was

encountered, or if there are no more directories to be

read.

DIAGNOSTICS

       cols="2" cellspacing="0" cellpadding="0">

<big>All error messages are directed to the</big>

TIFFError(3TIFF) routine. All warning messages are

directed to the TIFFWarning(3TIFF) routine.

<big>Seek error accessing TIFF directory. An error</big>

occurred while positioning to the location of the

directory.

<big>Wrong data type %d for field "%s".</big>

The tag entry in the directory had an incorrect data type.

For example, an ImageDescription tag with a

SHORT <big>data type.</big>

<big>TIFF directory is missing required "%s"</big>

field. The specified tag is required to be present by

the TIFF <big>5.0 specification, but is missing. The</big>

directory is (usually) unusable.

<big>%s: Rational with zero denominator. A</big>

directory tag has a RATIONAL <big>value whose</big>

denominator is zero.

<big>Incorrect count %d for field "%s" (%lu,</big>

expecting %lu); tag ignored. The specified tag’s

count field is bad. For example, a count other than 1 for a

SubFileType tag.

<big>Cannot handle different per-sample values for</big>

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.

<big>Count mismatch for field "%s";</big>

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.

<big>Invalid TIFF directory; tags are not sorted in</big>

ascending order. The directory tags are not properly

sorted as specified in the TIFF <big>5.0</big>

specification. This error is not fatal.

<big>Ignoring unknown field with tag %d (0x%x). An</big>

unknown tag was encountered in the directory; the library

ignores all such tags.

<big>TIFF directory is missing requred</big>

"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.

<big>TIFF directory is missing requred</big>

"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.

<big>TIFF directory is missing requred</big>

"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

library to recover from this error.

<big>TIFF directory is missing requred</big>

"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 library to

recover from this error.

<big>TIFF directory is missing required</big>

"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.

<big>TIFF directory is missing required</big>

"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.

<big>Bogus "StripByteCounts" field, ignoring</big>

and calculating from imagelength. 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 missing value based on the file

size.

SEE ALSO

       cols="2" cellspacing="0" cellpadding="0">

<big>TIFFOpen(3TIFF),</big>

TIFFWriteDirectory(3TIFF),

TIFFSetDirectory(3TIFF),

TIFFSetSubDirectory(3TIFF),

libtiff(3TIFF)

<big>Libtiff library home page:</big>

http://www.remotesensing.org/libtiff/