com.drew.metadata.jpeg
Class JpegDirectory

java.lang.Object
  extended by com.drew.metadata.Directory
      extended by com.drew.metadata.jpeg.JpegDirectory
All Implemented Interfaces:
java.io.Serializable

public class JpegDirectory
extends Directory

Directory of tags and values for the SOF0 Jpeg segment. This segment holds basic metadata about the image.

Author:
Darrell Silver http://www.darrellsilver.com and Drew Noakes
See Also:
Serialized Form

Field Summary
static int TAG_JPEG_COMPONENT_DATA_1
          the first of a possible 4 color components.
static int TAG_JPEG_COMPONENT_DATA_2
          the second of a possible 4 color components.
static int TAG_JPEG_COMPONENT_DATA_3
          the third of a possible 4 color components.
static int TAG_JPEG_COMPONENT_DATA_4
          the fourth of a possible 4 color components.
static int TAG_JPEG_DATA_PRECISION
          This is in bits/sample, usually 8 (12 and 16 not supported by most software).
static int TAG_JPEG_IMAGE_HEIGHT
          The image's height.
static int TAG_JPEG_IMAGE_WIDTH
          The image's width.
static int TAG_JPEG_NUMBER_OF_COMPONENTS
          Usually 1 = grey scaled, 3 = color YcbCr or YIQ, 4 = color CMYK Each component TAG_COMPONENT_DATA_[1-4], has the following meaning: component Id(1byte)(1 = Y, 2 = Cb, 3 = Cr, 4 = I, 5 = Q), sampling factors (1byte) (bit 0-3 vertical., 4-7 horizontal.), quantization table number (1 byte).
protected static java.util.HashMap tagNameMap
           
 
Fields inherited from class com.drew.metadata.Directory
_definedTagList, _descriptor, _tagMap
 
Constructor Summary
JpegDirectory()
           
 
Method Summary
 JpegComponent getComponent(int componentNumber)
           
 int getImageHeight()
           
 int getImageWidth()
           
 java.lang.String getName()
          Provides the name of the directory, for display purposes.
 int getNumberOfComponents()
           
protected  java.util.HashMap getTagNameMap()
          Provides the map of tag names, hashed by tag type identifier.
 
Methods inherited from class com.drew.metadata.Directory
addError, containsTag, getBoolean, getByteArray, getDate, getDescription, getDouble, getErrorCount, getErrors, getFloat, getInt, getIntArray, getLong, getObject, getRational, getRationalArray, getString, getStringArray, getTagCount, getTagIterator, getTagName, hasErrors, setBoolean, setByteArray, setDate, setDescriptor, setDouble, setFloat, setInt, setIntArray, setLong, setObject, setObjectArray, setRational, setRationalArray, setString, setStringArray
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

TAG_JPEG_DATA_PRECISION

public static final int TAG_JPEG_DATA_PRECISION
This is in bits/sample, usually 8 (12 and 16 not supported by most software).

See Also:
Constant Field Values

TAG_JPEG_IMAGE_HEIGHT

public static final int TAG_JPEG_IMAGE_HEIGHT
The image's height. Necessary for decoding the image, so it should always be there.

See Also:
Constant Field Values

TAG_JPEG_IMAGE_WIDTH

public static final int TAG_JPEG_IMAGE_WIDTH
The image's width. Necessary for decoding the image, so it should always be there.

See Also:
Constant Field Values

TAG_JPEG_NUMBER_OF_COMPONENTS

public static final int TAG_JPEG_NUMBER_OF_COMPONENTS
Usually 1 = grey scaled, 3 = color YcbCr or YIQ, 4 = color CMYK Each component TAG_COMPONENT_DATA_[1-4], has the following meaning: component Id(1byte)(1 = Y, 2 = Cb, 3 = Cr, 4 = I, 5 = Q), sampling factors (1byte) (bit 0-3 vertical., 4-7 horizontal.), quantization table number (1 byte).

This info is from http://www.funducode.com/freec/Fileformats/format3/format3b.htm

See Also:
Constant Field Values

TAG_JPEG_COMPONENT_DATA_1

public static final int TAG_JPEG_COMPONENT_DATA_1
the first of a possible 4 color components. Number of components specified in TAG_JPEG_NUMBER_OF_COMPONENTS.

See Also:
Constant Field Values

TAG_JPEG_COMPONENT_DATA_2

public static final int TAG_JPEG_COMPONENT_DATA_2
the second of a possible 4 color components. Number of components specified in TAG_JPEG_NUMBER_OF_COMPONENTS.

See Also:
Constant Field Values

TAG_JPEG_COMPONENT_DATA_3

public static final int TAG_JPEG_COMPONENT_DATA_3
the third of a possible 4 color components. Number of components specified in TAG_JPEG_NUMBER_OF_COMPONENTS.

See Also:
Constant Field Values

TAG_JPEG_COMPONENT_DATA_4

public static final int TAG_JPEG_COMPONENT_DATA_4
the fourth of a possible 4 color components. Number of components specified in TAG_JPEG_NUMBER_OF_COMPONENTS.

See Also:
Constant Field Values

tagNameMap

protected static final java.util.HashMap tagNameMap
Constructor Detail

JpegDirectory

public JpegDirectory()
Method Detail

getName

public java.lang.String getName()
Description copied from class: Directory
Provides the name of the directory, for display purposes. E.g. Exif

Specified by:
getName in class Directory
Returns:
the name of the directory

getTagNameMap

protected java.util.HashMap getTagNameMap()
Description copied from class: Directory
Provides the map of tag names, hashed by tag type identifier.

Specified by:
getTagNameMap in class Directory
Returns:
the map of tag names

getComponent

public JpegComponent getComponent(int componentNumber)
Parameters:
componentNumber - The zero-based index of the component. This number is normally between 0 and 3. Use getNumberOfComponents for bounds-checking.
Returns:

getImageWidth

public int getImageWidth()
                  throws MetadataException
Throws:
MetadataException

getImageHeight

public int getImageHeight()
                   throws MetadataException
Throws:
MetadataException

getNumberOfComponents

public int getNumberOfComponents()
                          throws MetadataException
Throws:
MetadataException


Copyright © 2006 Drew Noakes. All Rights Reserved.