Package com.drew.imaging.tiff

Class TiffReader

java.lang.Object

com.drew.imaging.tiff.TiffReader

public class TiffReader
extends Object

Processes TIFF-formatted data, calling into client code via that TiffHandler interface.

Constructor Summary

Constructors

Constructor	Description
TiffReader()

Method Summary

Modifier and Type	Method	Description
private static int	calculateTagOffset(int ifdStartOffset, int entryNumber)	Determine the offset of a given tag within the specified IFD.
static void	processIfd(TiffHandler handler, RandomAccessReader reader, Set<Integer> processedIfdOffsets, int ifdOffset, int tiffHeaderOffset)	Processes a TIFF IFD.
private static void	processTag(TiffHandler handler, int tagId, int tagValueOffset, int componentCount, int formatCode, RandomAccessReader reader)
void	processTiff(RandomAccessReader reader, TiffHandler handler, int tiffHeaderOffset)	Processes a TIFF data sequence.

Methods inherited from class java.lang.Object

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

Constructor Details

TiffReader

public TiffReader()

Method Details

processTiff

public void processTiff(RandomAccessReader reader,
 TiffHandler handler,
 int tiffHeaderOffset)
                 throws TiffProcessingException,
IOException

Processes a TIFF data sequence.

Parameters:

reader - the RandomAccessReader from which the data should be read

handler - the TiffHandler that will coordinate processing and accept read values

tiffHeaderOffset - the offset within reader at which the TIFF header starts

Throws:

TiffProcessingException - if an error occurred during the processing of TIFF data that could not be ignored or recovered from

IOException - an error occurred while accessing the required data

processIfd

public static void processIfd(TiffHandler handler,
 RandomAccessReader reader,
 Set<Integer> processedIfdOffsets,
 int ifdOffset,
 int tiffHeaderOffset)
                       throws IOException

Processes a TIFF IFD. IFD Header:

• 2 bytes number of tags

Tag structure:

• 2 bytes tag type
• 2 bytes format code (values 1 to 12, inclusive)
• 4 bytes component count
• 4 bytes inline value, or offset pointer if too large to fit in four bytes

Parameters:

handler - the TiffHandler that will coordinate processing and accept read values

reader - the RandomAccessReader from which the data should be read

processedIfdOffsets - the set of visited IFD offsets, to avoid revisiting the same IFD in an endless loop

ifdOffset - the offset within reader at which the IFD data starts

tiffHeaderOffset - the offset within reader at which the TIFF header starts

Throws:

IOException - an error occurred while accessing the required data

processTag

private static void processTag(TiffHandler handler,
 int tagId,
 int tagValueOffset,
 int componentCount,
 int formatCode,
 RandomAccessReader reader)
                        throws IOException

Throws:

IOException

calculateTagOffset

private static int calculateTagOffset(int ifdStartOffset,
 int entryNumber)

Determine the offset of a given tag within the specified IFD.

Parameters:

ifdStartOffset - the offset at which the IFD starts

entryNumber - the zero-based entry number