JPEGHuffmanTable (Java 2 Platform SE v1.4.1_"07")

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JavaTM 2 Platform
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## javax.imageio.plugins.jpeg
Class JPEGHuffmanTable

    java.lang.Object
      |
      +--javax.imageio.plugins.jpeg.JPEGHuffmanTable

public class JPEGHuffmanTable
extends Object

A class encapsulating a single JPEG Huffman table. Fields are provided for the "standard" tables from taken from Annex K of the JPEG specification. These are the tables used as defaults. This class differs from the old unsupported com.sun.image.codec.jpeg.JPEGHuffmanTable in two ways:

1. The lengths arrays for this class do not contain an ignored 0th entry. The lengths array in a JPEG stream does not contain an extra entry, and this class is used to represent the contents of a JPEG stream.
2. The old class incorrectly referred to Huffman "symbols", while expecting an array of values to be encoded. This class has a `getValues` method instead of a `getSymbols` method.

For more information about the operation of the built-in JPEG plug-ins, see the JPEG metadata format specification and usage notes.

Field Summary
`static JPEGHuffmanTable` | `StdACChrominance` The standard AC chrominance Huffman table.
`static JPEGHuffmanTable` | `StdACLuminance` The standard AC luminance Huffman table.
`static JPEGHuffmanTable` | `StdDCChrominance` The standard DC chrominance Huffman table.
`static JPEGHuffmanTable` | `StdDCLuminance` The standard DC luminance Huffman table.

Constructor Summary
`JPEGHuffmanTable(short[] lengths, short[] values)` Creates a Huffman table and initializes it.

Method Summary
`short[]` | `getLengths()` Return an array of `short`s containing the number of values for each length in the Huffman table.
`short[]` | `getValues()` Return an array of `short`s containing the values arranged by increasing length of their corresponding codes.
`String` | `toString()` Returns a string representation of the object.

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

Field Detail

### StdDCLuminance

    public static final JPEGHuffmanTable StdDCLuminance

  The standard DC luminance Huffman table.

### StdDCChrominance

    public static final JPEGHuffmanTable StdDCChrominance

  The standard DC chrominance Huffman table.

### StdACLuminance

    public static final JPEGHuffmanTable StdACLuminance

  The standard AC luminance Huffman table.

### StdACChrominance

    public static final JPEGHuffmanTable StdACChrominance

  The standard AC chrominance Huffman table.

Constructor Detail

### JPEGHuffmanTable

    public JPEGHuffmanTable(short[] lengths,
                            short[] values)

  Creates a Huffman table and initializes it. The input arrays are copied. The arrays must describe a possible Huffman table. For example, 3 codes cannot be expressed with a single bit.

Parameters:
  `lengths` - an array of `short`s where `lengths[k]` is equal to the number of values with corresponding codes of length `k + 1` bits.
  `values` - an array of `short`s containing the values in order of increasing code length.
Throws:
  `IllegalArgumentException` - if `lengths` or `values` are `null`, the length of `lengths` is greater than 16, the length of `values` is greater than 256, if any value in `lengths` or `values` is less than zero, or if the arrays do not describe a valid Huffman table.

Method Detail

### getLengths

    public short[] getLengths()

  Return an array of `short`s containing the number of values for each length in the Huffman table. The returned array is a copy.

  Returns:
    a `short` array where `array[k-1]` is equal to the number of values in the table of length `k`.
  See Also:
    `getValues()`

### getValues

    public short[] getValues()

  Return an array of `short`s containing the values arranged by increasing length of their corresponding codes. The interpretation of the array is dependent on the values returned from `getLengths`. The returned array is a copy.

  Returns:
    a `short` array of values.
  See Also:
    `getLengths()`

### toString

    public String toString()

  Description copied from class: `Object`
  Returns a string representation of the object. In general, the `toString` method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

  The `toString` method for class `Object` returns a string consisting of the name of the class of which the object is an instance, the at-sign character ``@`', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

  >      getClass().getName() + '@' + Integer.toHexString(hashCode())

  Overrides:
    `toString` in class `Object`
  Returns:
    a string representation of the object.

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For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright 2002 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms.