IFD (JHOVE - JSTOR/Harvard Object Validation Environment 1.16.0 API)

java.lang.Object
- edu.harvard.hul.ois.jhove.module.tiff.IFD

Direct Known Subclasses:

ExifIFD, GlobalParametersIFD, GPSInfoIFD, InteroperabilityIFD, TiffIFD
```
public abstract class IFD
extends Object
```
Encapsulation of a TIFF image file directory (IFD).

Field Summary

Fields
Modifier and Type	Field and Description
`protected boolean`	`_bigEndian` True if big-endian file.
`protected RepInfo`	`_info` Representation information.
`protected long`	`_next` Offset of next IFD.
`protected long`	`_offset` IFD offset.
`protected int`	`_version` TIFF version.
`static int`	`ASCII` TIFF ASCII type.
`static int`	`BYTE` TIFF BYTE (unsigned 8-bit) type.
`static int`	`DOUBLE` TIFF DOUBLE (64-bit IEEE floating point) type.
`static int`	`EXIF` Exif IFD.
`static int`	`FLOAT` TIFF FLOAT (32-bit IEEE floating point) type.
`static int`	`GLOBALPARAMETERS` Global parameters IFD.
`static int`	`GPSINFO` GPSInfo IFD.
`static int`	`IFD` TIFF IFD (LONG) type.
`static int`	`INTEROPERABILITY` Exif Interoperability IFD.
`static int`	`LONG` TIFF LONG (unsigned 32-bit) type.
`static int`	`NULL` Undefined value for integer tags.
`static int`	`RATIONAL` TIFF RATIONAL (two LONGs) type.
`static int`	`SBYTE` TIFF SBYTE (signed 8-bit) type.
`static int`	`SHORT` TIFF SHORT (unsigned 16-bit) type.
`static int`	`SLONG` TIFF SLONG (signed 32-bit) type.
`static int`	`SRATIONAL` TIFF SRATIONAL (two SLONGs) type.
`static int`	`SSHORT` TIFF SSHORT (signed 16-bit) type.
`static int`	`TIFF` Standard TIFF IFD.
`static String[]`	`TYPE` TIFF type labels.
`static int`	`UNDEFINED` TIFF UNDEFINED (unsigned 8-bit) type.

Constructor Summary

Constructors
Constructor and Description

IFD(long offset, RepInfo info, RandomAccessFile raf, boolean bigEndian)
Instantiate an IFD object.

Constructors
Constructor and Description
`IFD(long offset, RepInfo info, RandomAccessFile raf, boolean bigEndian)` Instantiate an `IFD` object.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`protected Property`	`addBitmaskProperty(String name, long value, String[] labels, boolean rawOutput)` Returns a Property representing a bitmask.
`protected Property`	`addIntegerArrayProperty(String name, int[] value, String[] labels, boolean rawOutput)` Returns an ARRAY Property representing an integer array.
`protected Property`	`addIntegerProperty(String name, int value, String[] labels, boolean rawOutput)` Returns an Property representing an integer value.
`protected Property`	`addIntegerProperty(String name, int value, String[] labels, int[] index, boolean rawOutput)` Returns an Property representing an integer value.
`protected Property`	`addRationalArrayProperty(String name, Rational[] r, boolean rawOutput)`
`protected Property`	`addRationalProperty(String name, Rational r, boolean rawOutput)` Returns a property for a tag with a RATIONAL value.
`protected static Rational`	`average(Rational r1, Rational r2)`
`static long`	`calcValueSize(int type, long count)` Calculate how many bytes a given number of fields of a given type will require.
`protected static void`	`checkCount(int tag, long count, int minCount)` Check the tag entry count.
`protected static void`	`checkType(int tag, int type, int expected)` Check the tag entry type.
`protected static void`	`checkType(int tag, int type, int type1, int type2)` Check the tag entry type.
`List<String>`	`getErrors()` Get any errors discovered during parsing.
`long`	`getNext()` Get the offset of the next IFD.
`long`	`getOffset()` Get the IFD offset.
`abstract Property`	`getProperty(boolean rawOutput)` Get the IFD properties.
`int`	`getVersion()` Get the TIFF version.
`boolean`	`isBigEndian()` Returns `true` if file is big-endian, `false` if little-endian.
`boolean`	`isFirst()` Return true if this is the first IFD.
`boolean`	`isThumbnail()` Return true if this is the thumbnail IFD.
`abstract void`	`lookupTag(int tag, int type, long count, long value)` Lookup IFD tag.
`long`	`parse()` Parse the IFD.
`long`	`parse(boolean byteOffsetIsValid)` Parse the IFD.
`long`	`parse(boolean byteOffsetIsValid, boolean suppressErrors)` Parse the IFD.
`protected void`	`postParseInitialization()` Perform initializations that have to wait until after the IFD has been parsed.
`protected Property`	`propertyHeader(String type, List entries)` Standard IFD property header.
`protected String`	`readASCII(long count, long value)` Reads a string value from the TIFF file.
`protected String[]`	`readASCIIArray(long count, long value)` Reads an array of strings from the TIFF file.
`protected int`	`readByte(int type, long count, long value)` Reads and returns a single unsigned 8-bit integer value.
`protected int[]`	`readByteArray(int type, long count, long value)` Reads an array of bytes and returns it as an int array.
`protected double[]`	`readDoubleArray(long count, long value)` Reads a TIFF array of DOUBLE 64-bit values and returns it as a double array.
`protected long`	`readLong(int type, long count, long value)` Reads and returns a single unsigned 32-bit integer value.
`protected long[]`	`readLongArray(int type, long count, long value)` Reads a TIFF array of signed 32-bit integer values and returns it as a long array.
`protected Rational`	`readRational(long count, long value)` Reads a RATIONAL value and returns it as a Rational.
`protected Rational[]`	`readRationalArray(long count, long value)` Reads an array of RATIONAL values and returns it as an array of Rational.
`protected int`	`readShort(int type, long count, long value)` Reads and returns a single unsigned 16-bit value.
`protected int[]`	`readShortArray(int type, long count, long value)` Reads a TIFF array of unsigned 16-bit values and returns it as an int array.
`protected Rational`	`readSignedRational(long count, long value)` Reads an SRATIONAL value and returns it as a Rational.
`protected Rational[]`	`readSignedRationalArray(long count, long value)` Reads an array of SRATIONAL values and returns it as an array of Rational.
`protected int[]`	`readSShortArray(int type, long count, long value)` Reads a TIFF array of signed 16-bit values and returns it as an int array.
`protected byte[]`	`readTrueByteArray(int type, long count, long value)` Reads an array of bytes and returns it as a byte array.
`long`	`readUnsigned(int type)` Reads an unsigned number of any type.
`void`	`setFirst(boolean first)` Sets flag indicating whether this is the first IFD.
`void`	`setThumbnail(boolean thumbnail)` Sets flag indicating whether this is the "thumbnail" IFD.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - TIFF
```
public static final int TIFF
```
    Standard TIFF IFD.
    
    See Also:
    
    Constant Field Values
  - EXIF
```
public static final int EXIF
```
    Exif IFD.
    
    See Also:
    
    Constant Field Values
  - INTEROPERABILITY
```
public static final int INTEROPERABILITY
```
    Exif Interoperability IFD.
    
    See Also:
    
    Constant Field Values
  - GPSINFO
```
public static final int GPSINFO
```
    GPSInfo IFD.
    
    See Also:
    
    Constant Field Values
  - GLOBALPARAMETERS
```
public static final int GLOBALPARAMETERS
```
    Global parameters IFD.
    
    See Also:
    
    Constant Field Values
  - NULL
```
public static final int NULL
```
    Undefined value for integer tags.
    
    See Also:
    
    Constant Field Values
  - BYTE
```
public static final int BYTE
```
    TIFF BYTE (unsigned 8-bit) type.
    
    See Also:
    
    Constant Field Values
  - ASCII
```
public static final int ASCII
```
    TIFF ASCII type.
    
    See Also:
    
    Constant Field Values
  - SHORT
```
public static final int SHORT
```
    TIFF SHORT (unsigned 16-bit) type.
    
    See Also:
    
    Constant Field Values
  - LONG
```
public static final int LONG
```
    TIFF LONG (unsigned 32-bit) type.
    
    See Also:
    
    Constant Field Values
  - RATIONAL
```
public static final int RATIONAL
```
    TIFF RATIONAL (two LONGs) type.
    
    See Also:
    
    Constant Field Values
  - SBYTE
```
public static final int SBYTE
```
    TIFF SBYTE (signed 8-bit) type.
    
    See Also:
    
    Constant Field Values
  - UNDEFINED
```
public static final int UNDEFINED
```
    TIFF UNDEFINED (unsigned 8-bit) type.
    
    See Also:
    
    Constant Field Values
  - SSHORT
```
public static final int SSHORT
```
    TIFF SSHORT (signed 16-bit) type.
    
    See Also:
    
    Constant Field Values
  - SLONG
```
public static final int SLONG
```
    TIFF SLONG (signed 32-bit) type.
    
    See Also:
    
    Constant Field Values
  - SRATIONAL
```
public static final int SRATIONAL
```
    TIFF SRATIONAL (two SLONGs) type.
    
    See Also:
    
    Constant Field Values
  - FLOAT
```
public static final int FLOAT
```
    TIFF FLOAT (32-bit IEEE floating point) type.
    
    See Also:
    
    Constant Field Values
  - DOUBLE
```
public static final int DOUBLE
```
    TIFF DOUBLE (64-bit IEEE floating point) type.
    
    See Also:
    
    Constant Field Values
  - IFD
```
public static final int IFD
```
    TIFF IFD (LONG) type.
    
    See Also:
    
    Constant Field Values
  - TYPE
```
public static final String[] TYPE
```
    TIFF type labels.
  - _bigEndian
```
protected boolean _bigEndian
```
    True if big-endian file.
  - _info
```
protected RepInfo _info
```
    Representation information.
  - _next
```
protected long _next
```
    Offset of next IFD.
  - _offset
```
protected long _offset
```
    IFD offset.
  - _version
```
protected int _version
```
    TIFF version.
- Constructor Detail
  - IFD
```
public IFD(long offset,
           RepInfo info,
           RandomAccessFile raf,
           boolean bigEndian)
```
    Instantiate an IFD object.
    
    Parameters:
    
    offset - IFD offset
    
    info - Representation information
    
    raf - TIFF file
    
    bigEndian - True if big-endian file
- Method Detail
  - getErrors
```
public List<String> getErrors()
```
    Get any errors discovered during parsing.
  - getNext
```
public long getNext()
```
    Get the offset of the next IFD.
  - getOffset
```
public long getOffset()
```
    Get the IFD offset.
  - getProperty
```
public abstract Property getProperty(boolean rawOutput)
                              throws TiffException
```
    Get the IFD properties.
    
    Throws:
    
    TiffException
  - getVersion
```
public int getVersion()
```
    Get the TIFF version.
  - isFirst
```
public boolean isFirst()
```
    Return true if this is the first IFD.
  - isThumbnail
```
public boolean isThumbnail()
```
    Return true if this is the thumbnail IFD.
  - lookupTag
```
public abstract void lookupTag(int tag,
                               int type,
                               long count,
                               long value)
                        throws TiffException
```
    Lookup IFD tag.
    
    Throws:
    
    TiffException
  - parse
```
public long parse()
           throws TiffException
```
    Parse the IFD. Errors are not suppressed, and odd byte offsets for tags not allowed.
    
    Returns:
    
    The offset of the next IFD
    
    Throws:
    
    TiffException
  - parse
```
public long parse(boolean byteOffsetIsValid,
                  boolean suppressErrors)
           throws TiffException
```
    Parse the IFD.
    
    Parameters:
    
    byteOffsetIsValid - If true, allow offsets on odd byte boundaries
    
    suppressErrors - If true, return IFD even with errors
    
    Returns:
    
    The offset of the next IFD
    
    Throws:
    
    TiffException
  - parse
```
public long parse(boolean byteOffsetIsValid)
           throws TiffException
```
    Parse the IFD. Errors are not suppressed.
    
    Parameters:
    
    byteOffsetIsValid - If true, allow offsets on odd byte boundaries
    
    Returns:
    
    The offset of the next IFD
    
    Throws:
    
    TiffException
  - setFirst
```
public void setFirst(boolean first)
```
    Sets flag indicating whether this is the first IFD.
  - setThumbnail
```
public void setThumbnail(boolean thumbnail)
```
    Sets flag indicating whether this is the "thumbnail" IFD. The second IFD in the top-level chain is assumed to be the Thumbnail IFD.
  - addBitmaskProperty
```
protected Property addBitmaskProperty(String name,
                                      long value,
                                      String[] labels,
                                      boolean rawOutput)
```
    Returns a Property representing a bitmask. If rawOutput is true, returns a LIST property whose elements are STRING properties. The string values of these STRING properties are the elements of labels whose indices correspond to 1 bits in the bitmask, counting the low-order bit as bit 0. if rawOutput is false, returns a LONG property whose numeric value is value.
  - addIntegerProperty
```
protected Property addIntegerProperty(String name,
                                      int value,
                                      String[] labels,
                                      boolean rawOutput)
```
    Returns an Property representing an integer value. If rawOutput is true, returns an INTEGER property, and labels and index are unused. Otherwise, returns a STRING property, with the string being the element of labels whose index is value.
  - addIntegerProperty
```
protected Property addIntegerProperty(String name,
                                      int value,
                                      String[] labels,
                                      int[] index,
                                      boolean rawOutput)
```
    Returns an Property representing an integer value. If rawOutput is true, returns an INTEGER property, and labels and index are unused. Otherwise, returns a STRING property, with the string being the element of labels whose index is the index of value in index.
  - addIntegerArrayProperty
```
protected Property addIntegerArrayProperty(String name,
                                           int[] value,
                                           String[] labels,
                                           boolean rawOutput)
```
    Returns an ARRAY Property representing an integer array. If rawOutput is true, the elements of the property array are INTEGER properties, and labels is unused. Otherwise, the elements of the array are STRING properties, with the elements of value used as indices into labels.
  - addRationalProperty
```
protected Property addRationalProperty(String name,
                                       Rational r,
                                       boolean rawOutput)
```
    Returns a property for a tag with a RATIONAL value. If rawOutput is true, returns a property with type RATIONAL. Otherwise, returns a property with type STRING, and the text representation of the Rational value as a floating-point ratio.
  - addRationalArrayProperty
```
protected Property addRationalArrayProperty(String name,
                                            Rational[] r,
                                            boolean rawOutput)
```
  - postParseInitialization
```
protected void postParseInitialization()
```
    Perform initializations that have to wait until after the IFD has been parsed.
  - propertyHeader
```
protected Property propertyHeader(String type,
                                  List entries)
```
    Standard IFD property header.
  - readASCII
```
protected String readASCII(long count,
                           long value)
                    throws IOException
```
    Reads a string value from the TIFF file. If there are non-ASCII characters, they're escaped as %XX
    
    Parameters:
    
    count - Length of string
    
    value - Offset of string
    
    Throws:
    
    IOException
  - readASCIIArray
```
protected String[] readASCIIArray(long count,
                                  long value)
                           throws IOException
```
    Reads an array of strings from the TIFF file.
    
    Parameters:
    
    count - Number of strings to read
    
    value - Offset from which to read
    
    Throws:
    
    IOException
  - readByte
```
protected int readByte(int type,
                       long count,
                       long value)
                throws IOException
```
    Reads and returns a single unsigned 8-bit integer value.
    
    Parameters:
    
    type - TIFF type to read; must be an 8-bit type
    
    count - Unused
    
    value - Offset from which to read
    
    Throws:
    
    IOException
  - readByteArray
```
protected int[] readByteArray(int type,
                              long count,
                              long value)
                       throws IOException
```
    Reads an array of bytes and returns it as an int array.
    
    Parameters:
    
    type - TIFF type to read; must be an 8-bit type
    
    count - Number of bytes to read
    
    value - Offset from which to read
    
    Throws:
    
    IOException
  - readTrueByteArray
```
protected byte[] readTrueByteArray(int type,
                                   long count,
                                   long value)
                            throws IOException
```
    Reads an array of bytes and returns it as a byte array.
    
    Parameters:
    
    type - Unused
    
    count - Number of bytes to read
    
    value - Offset from which to read
    
    Throws:
    
    IOException
  - readDoubleArray
```
protected double[] readDoubleArray(long count,
                                   long value)
                            throws IOException
```
    Reads a TIFF array of DOUBLE 64-bit values and returns it as a double array.
    
    Parameters:
    
    count - Number of values to read
    
    value - Offset from which to read
    
    Throws:
    
    IOException
  - readLong
```
protected long readLong(int type,
                        long count,
                        long value)
                 throws IOException
```
    Reads and returns a single unsigned 32-bit integer value.
    
    Parameters:
    
    type - TIFF type to read; must be a 32-bit type
    
    count - Unused
    
    value - Offset from which to read
    
    Throws:
    
    IOException
  - readLongArray
```
protected long[] readLongArray(int type,
                               long count,
                               long value)
                        throws IOException
```
    Reads a TIFF array of signed 32-bit integer values and returns it as a long array.
    
    Parameters:
    
    type - TIFF type to read; must be a 32-bit type
    
    count - Number of values to read
    
    value - Offset from which to read
    
    Throws:
    
    IOException
  - readUnsigned
```
public long readUnsigned(int type)
                  throws IOException
```
    Reads an unsigned number of any type.
    
    Parameters:
    
    type - TIFF type to read
    
    Throws:
    
    IOException
  - readRational
```
protected Rational readRational(long count,
                                long value)
                         throws IOException
```
    Reads a RATIONAL value and returns it as a Rational.
    
    Throws:
    
    IOException
  - readRationalArray
```
protected Rational[] readRationalArray(long count,
                                       long value)
                                throws IOException
```
    Reads an array of RATIONAL values and returns it as an array of Rational.
    
    Throws:
    
    IOException
  - readSignedRational
```
protected Rational readSignedRational(long count,
                                      long value)
                               throws IOException
```
    Reads an SRATIONAL value and returns it as a Rational.
    
    Throws:
    
    IOException
  - readSignedRationalArray
```
protected Rational[] readSignedRationalArray(long count,
                                             long value)
                                      throws IOException
```
    Reads an array of SRATIONAL values and returns it as an array of Rational.
    
    Throws:
    
    IOException
  - readShort
```
protected int readShort(int type,
                        long count,
                        long value)
                 throws IOException
```
    Reads and returns a single unsigned 16-bit value.
    
    Throws:
    
    IOException
  - readShortArray
```
protected int[] readShortArray(int type,
                               long count,
                               long value)
                        throws IOException
```
    Reads a TIFF array of unsigned 16-bit values and returns it as an int array.
    
    Throws:
    
    IOException
  - readSShortArray
```
protected int[] readSShortArray(int type,
                                long count,
                                long value)
                         throws IOException
```
    Reads a TIFF array of signed 16-bit values and returns it as an int array.
    
    Throws:
    
    IOException
  - calcValueSize
```
public static long calcValueSize(int type,
                                 long count)
```
    Calculate how many bytes a given number of fields of a given type will require.
    
    Parameters:
    
    type - Field type
    
    count - Field count
  - isBigEndian
```
public boolean isBigEndian()
```
    Returns true if file is big-endian, false if little-endian.
  - checkCount
```
protected static void checkCount(int tag,
                                 long count,
                                 int minCount)
                          throws TiffException
```
    Check the tag entry count.
    
    Parameters:
    
    tag - Tag entry value
    
    count - Tag entry count
    
    minCount - Tag count
    
    Throws:
    
    TiffException
  - checkType
```
protected static void checkType(int tag,
                                int type,
                                int expected)
                         throws TiffException
```
    Check the tag entry type.
    
    Parameters:
    
    tag - Tag entry value
    
    type - Tag entry type
    
    expected - Tag type
    
    Throws:
    
    TiffException
  - checkType
```
protected static void checkType(int tag,
                                int type,
                                int type1,
                                int type2)
                         throws TiffException
```
    Check the tag entry type.
    
    Parameters:
    
    tag - Tag entry value
    
    type - Tag entry type
    
    type1 - Tag type
    
    type2 - Alternate tag type
    
    Throws:
    
    TiffException
  - average
```
protected static Rational average(Rational r1,
                                  Rational r2)
```

Class IFD

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

TIFF

EXIF

INTEROPERABILITY

GPSINFO

GLOBALPARAMETERS

NULL

BYTE

ASCII

SHORT

LONG

RATIONAL

SBYTE

UNDEFINED

SSHORT

SLONG

SRATIONAL

FLOAT

DOUBLE

IFD

TYPE

_bigEndian

_info

_next

_offset

_version

Constructor Detail

IFD

Method Detail

getErrors

getNext

getOffset

getProperty

getVersion

isFirst

isThumbnail

lookupTag

parse

parse

parse

setFirst

setThumbnail

addBitmaskProperty

addIntegerProperty

addIntegerProperty

addIntegerArrayProperty

addRationalProperty

addRationalArrayProperty

postParseInitialization

propertyHeader

readASCII

readASCIIArray

readByte

readByteArray

readTrueByteArray

readDoubleArray

readLong

readLongArray

readUnsigned

readRational

readRationalArray

readSignedRational

readSignedRationalArray

readShort

readShortArray

readSShortArray

calcValueSize

isBigEndian

checkCount

checkType

checkType

average