Overview  Package   Class  Use  Deprecated  Index
Home >> All >> com >> drew >> imaging >> [ jpeg overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---

com.drew.imaging.jpeg
Class JpegSegmentReader  

java.lang.Object
  com.drew.imaging.jpeg.JpegSegmentReader

---

public class JpegSegmentReader

extends java.lang.Object

Performs read functions of Jpeg files, returning specific file segments. TODO add a findAvailableSegments() method TODO add more segment identifiers TODO add a getSegmentDescription() method, returning for example 'App1 application data segment, commonly containing Exif data'

---

Field Summary
private  byte[]	_data           Jpeg data as byte array.
private  java.io.File	_file           Jpeg file.
private  java.util.HashMap	_segmentDataMap
private  java.io.InputStream	_stream           Jpeg data as an InputStream.
private static byte	MARKER_EOI           Private, because one wouldn't search for it.
static byte	SEGMENT_APP0           APP0 Jpeg segment identifier -- Jfif data.
static byte	SEGMENT_APP1           APP1 Jpeg segment identifier -- where Exif data is kept.
static byte	SEGMENT_APP2           APP2 Jpeg segment identifier.
static byte	SEGMENT_APP3           APP3 Jpeg segment identifier.
static byte	SEGMENT_APP4           APP4 Jpeg segment identifier.
static byte	SEGMENT_APP5           APP5 Jpeg segment identifier.
static byte	SEGMENT_APP6           APP6 Jpeg segment identifier.
static byte	SEGMENT_APP7           APP7 Jpeg segment identifier.
static byte	SEGMENT_APP8           APP8 Jpeg segment identifier.
static byte	SEGMENT_APP9           APP9 Jpeg segment identifier.
static byte	SEGMENT_APPA           APPA Jpeg segment identifier.
static byte	SEGMENT_APPB           APPB Jpeg segment identifier.
static byte	SEGMENT_APPC           APPC Jpeg segment identifier.
static byte	SEGMENT_APPD           APPD Jpeg segment identifier -- IPTC data in here.
static byte	SEGMENT_APPE           APPE Jpeg segment identifier.
static byte	SEGMENT_APPF           APPF Jpeg segment identifier.
static byte	SEGMENT_DHT           Define Huffman Table segment identifier.
static byte	SEGMENT_DQT           Define Quantization Table segment identifier.
static byte	SEGMENT_SOF0           Start-of-Frame Zero segment identifier.
static byte	SEGMENT_SOI           Start Of Image segment identifier.
private static byte	SEGMENT_SOS           Private, because this segment crashes my algorithm, and searching for it doesn't work (yet).

 

Constructor Summary

JpegSegmentReader(byte[] fileContents)           Creates a JpegSegmentReader for a byte array.

JpegSegmentReader(java.io.File file)           Creates a JpegSegmentReader for a specific file.

JpegSegmentReader(java.io.InputStream in)

 

Method Summary
private  java.io.BufferedInputStream	getJpegInputStream()           Private helper method to create a BufferedInputStream of Jpeg data from whichever data source was specified upon construction of this instance.
int	getSegmentCount(byte segmentMarker)
private  boolean	isValidJpegHeaderBytes(java.io.InputStream fileStream)           Helper method that validates the Jpeg file's magic number.
byte[]	readSegment(byte segmentMarker)           Reads the first instance of a given Jpeg segment, returning the contents as a byte array.
byte[]	readSegment(byte segmentMarker, int occurrence)           Reads the first instance of a given Jpeg segment, returning the contents as a byte array.
private  void	readSegments()

 

Methods inherited from class java.lang.Object

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

 

Field Detail

_file

private java.io.File _file

Jpeg file.

---

_data

private byte[] _data

Jpeg data as byte array.

---

_stream

private java.io.InputStream _stream

Jpeg data as an InputStream.

---

_segmentDataMap

private java.util.HashMap _segmentDataMap

---

SEGMENT_SOS

private static byte SEGMENT_SOS

Private, because this segment crashes my algorithm, and searching for it doesn't work (yet).

---

MARKER_EOI

private static byte MARKER_EOI

Private, because one wouldn't search for it.

---

SEGMENT_APP0

public static final byte SEGMENT_APP0

APP0 Jpeg segment identifier -- Jfif data.

See Also:

Constant Field Values

---

SEGMENT_APP1

public static final byte SEGMENT_APP1

APP1 Jpeg segment identifier -- where Exif data is kept.

See Also:

Constant Field Values

---

SEGMENT_APP2

public static final byte SEGMENT_APP2

APP2 Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_APP3

public static final byte SEGMENT_APP3

APP3 Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_APP4

public static final byte SEGMENT_APP4

APP4 Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_APP5

public static final byte SEGMENT_APP5

APP5 Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_APP6

public static final byte SEGMENT_APP6

APP6 Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_APP7

public static final byte SEGMENT_APP7

APP7 Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_APP8

public static final byte SEGMENT_APP8

APP8 Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_APP9

public static final byte SEGMENT_APP9

APP9 Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_APPA

public static final byte SEGMENT_APPA

APPA Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_APPB

public static final byte SEGMENT_APPB

APPB Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_APPC

public static final byte SEGMENT_APPC

APPC Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_APPD

public static final byte SEGMENT_APPD

APPD Jpeg segment identifier -- IPTC data in here.

See Also:

Constant Field Values

---

SEGMENT_APPE

public static final byte SEGMENT_APPE

APPE Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_APPF

public static final byte SEGMENT_APPF

APPF Jpeg segment identifier.

See Also:

Constant Field Values

---

SEGMENT_SOI

public static final byte SEGMENT_SOI

Start Of Image segment identifier.

See Also:

Constant Field Values

---

SEGMENT_DQT

public static final byte SEGMENT_DQT

Define Quantization Table segment identifier.

See Also:

Constant Field Values

---

SEGMENT_DHT

public static final byte SEGMENT_DHT

Define Huffman Table segment identifier.

See Also:

Constant Field Values

---

SEGMENT_SOF0

public static final byte SEGMENT_SOF0

Start-of-Frame Zero segment identifier.

See Also:

Constant Field Values

Constructor Detail

JpegSegmentReader

public JpegSegmentReader(java.io.File file)
                  throws java.io.FileNotFoundException,
                         JpegProcessingException

Creates a JpegSegmentReader for a specific file.

---

JpegSegmentReader

public JpegSegmentReader(byte[] fileContents)
                  throws JpegProcessingException

Creates a JpegSegmentReader for a byte array.

---

JpegSegmentReader

public JpegSegmentReader(java.io.InputStream in)
                  throws JpegProcessingException

Method Detail

readSegment

public byte[] readSegment(byte segmentMarker)
                   throws JpegProcessingException

Reads the first instance of a given Jpeg segment, returning the contents as a byte array.

---

readSegment

public byte[] readSegment(byte segmentMarker,
                          int occurrence)
                   throws JpegProcessingException

Reads the first instance of a given Jpeg segment, returning the contents as a byte array.

---

getSegmentCount

public int getSegmentCount(byte segmentMarker)

---

readSegments

private void readSegments()
                   throws JpegProcessingException

---

getJpegInputStream

private java.io.BufferedInputStream getJpegInputStream()
                                                throws JpegProcessingException

Private helper method to create a BufferedInputStream of Jpeg data from whichever data source was specified upon construction of this instance.

---

isValidJpegHeaderBytes

private boolean isValidJpegHeaderBytes(java.io.InputStream fileStream)
                                throws java.io.IOException

Helper method that validates the Jpeg file's magic number.

---

Overview  Package   Class  Use  Deprecated  Index
Home >> All >> com >> drew >> imaging >> [ jpeg overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---