org.w3c.tools.jpeg
Class ExifData

java.lang.Object
  org.w3c.tools.jpeg.ExifData

public class ExifData
extends java.lang.Object

An internal API for decoding EXIF data.

This class identifies a byte array as valid EXIF and provides methods for converting the internal representation of types to equivalent Java types.

This is a separate class in order to facilitate writing decoders for unknown fields.

Special note: string values are %-encoded to protect the caller from values that might not be legitimate UTF-8 strings.

Bugs:

The EXIF format includes unsigned integers which aren't directly available in Java. Unless I'm mistaken, they'd have to be turned into longs. But that would be inconvenient in other APIs. For the moment, I'm just treating them all as signed. I've never seen an EXIF unsigned value too large to represent in a Java int.

See Also:

Exif

Field Summary

static int[]	bytesPerFormat
static int	FMT_BYTE
static int	FMT_DOUBLE
static int	FMT_SBYTE
static int	FMT_SINGLE
static int	FMT_SLONG
static int	FMT_SRATIONAL
static int	FMT_SSHORT
static int	FMT_STRING
static int	FMT_ULONG
static int	FMT_UNDEFINED
static int	FMT_URATIONAL
static int	FMT_USHORT
static int	NUM_FORMATS

Constructor Summary

ExifData(byte[] exifData)

Method Summary

double	convertAnyValue(int format, int offset)
int	get16s(int offset)
int	get16u(int offset)
int	get32s(int offset)
int	get32u(int offset)
byte[]	getBytes(int offset, int length)
java.lang.String	getString(int offset, int length)
protected java.lang.String	getString(int offset, int length, boolean nullTerminated)
java.lang.String	getUndefined(int offset, int length)
boolean	isExifData()

Methods inherited from class java.lang.Object

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

Field Detail

bytesPerFormat

public static final int[] bytesPerFormat

NUM_FORMATS

public static final int NUM_FORMATS

See Also:

Constant Field Values

FMT_BYTE

public static final int FMT_BYTE

See Also:

Constant Field Values

FMT_STRING

public static final int FMT_STRING

See Also:

Constant Field Values

FMT_USHORT

public static final int FMT_USHORT

See Also:

Constant Field Values

FMT_ULONG

public static final int FMT_ULONG

See Also:

Constant Field Values

FMT_URATIONAL

public static final int FMT_URATIONAL

See Also:

Constant Field Values

FMT_SBYTE

public static final int FMT_SBYTE

See Also:

Constant Field Values

FMT_UNDEFINED

public static final int FMT_UNDEFINED

See Also:

Constant Field Values

FMT_SSHORT

public static final int FMT_SSHORT

See Also:

Constant Field Values

FMT_SLONG

public static final int FMT_SLONG

See Also:

Constant Field Values

FMT_SRATIONAL

public static final int FMT_SRATIONAL

See Also:

Constant Field Values

FMT_SINGLE

public static final int FMT_SINGLE

See Also:

Constant Field Values

FMT_DOUBLE

public static final int FMT_DOUBLE

See Also:

Constant Field Values

Constructor Detail

ExifData

public ExifData(byte[] exifData)

Method Detail

isExifData

public boolean isExifData()

get16s

public int get16s(int offset)

get16u

public int get16u(int offset)

get32s

public int get32s(int offset)

get32u

public int get32u(int offset)

getBytes

public byte[] getBytes(int offset,
                       int length)

getString

public java.lang.String getString(int offset,
                                  int length)

getUndefined

public java.lang.String getUndefined(int offset,
                                     int length)

getString

protected java.lang.String getString(int offset,
                                     int length,
                                     boolean nullTerminated)

convertAnyValue

public double convertAnyValue(int format,
                              int offset)