edu.harvard.hul.ois.jhove.module.jpeg
Class SpiffDir

java.lang.Object
  edu.harvard.hul.ois.jhove.module.jpeg.SpiffDir

public class SpiffDir
extends java.lang.Object

This class represents a SPIFF directory and the tags defined under it. A SPIFF directory consists of one or more APP8 segments, and may define ancillary images. It is always contained within the primary image stream.

Author:

Gary McGath

Constructor Summary

SpiffDir(JpegModule module)

Method Summary

void	appendThumbnailProps(java.util.List imageList) Appends any thumbnail properties that have been collected to the provided list.
void	readDirEntry(java.io.DataInputStream dstream, int length) Reads a directory entry, starting at the position after the APP8 marker and length.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SpiffDir

public SpiffDir(JpegModule module)

Method Detail

readDirEntry

public void readDirEntry(java.io.DataInputStream dstream,
                         int length)
                  throws java.io.IOException

Reads a directory entry, starting at the position after the APP8 marker and length. If the entry is for a thumbnail, create a Property for that thumbnail and add it to the thumbnail list. Other tags provide interesting information, some of which should go into properties, but for the moment we just handle the thumbnail and ignore other tags. An APP8 segment which is in a SPIFF file, and isn't the first APP8 segment (file header), is presumed to be a directory entry. These directory entries are a little inconvenient, because they can contain offsets to data in what we otherwise handle as a stream format. The offsets can be either to data within the block, or to faraway indirect data blocks. For the present version, we ignore offset data, which seems to be used only for the actual image bits (e.g., TNDATA).

Throws:

java.io.IOException

appendThumbnailProps

public void appendThumbnailProps(java.util.List imageList)

Appends any thumbnail properties that have been collected to the provided list.