javax.imageio.plugins.jpeg

Class JPEGHuffmanTable

public class JPEGHuffmanTable extends Object

The JPEGHuffmanTable class represents a Huffman table read from a JPEG image file. The standard JPEG AC and DC chrominance and luminance values are provided as static fields.

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

Constructor Summary
	JPEGHuffmanTable(short[] lengths, short[] values) Construct and initialize a Huffman table.

Method Summary
short[]	getLengths() Retrieve a copy of the array of Huffman code lengths.
short[]	getValues() Retrieve a copy of the array of Huffman values, sorted in order of increasing code length.
String	toString() Create a string representation of this JPEG Huffman table.

Field Detail

StdACChrominance

public static final JPEGHuffmanTable StdACChrominance

The standard JPEG AC chrominance Huffman table.

StdACLuminance

public static final JPEGHuffmanTable StdACLuminance

The standard JPEG AC luminance Huffman table.

StdDCChrominance

public static final JPEGHuffmanTable StdDCChrominance

The standard JPEG DC chrominance Huffman table.

StdDCLuminance

public static final JPEGHuffmanTable StdDCLuminance

The standard JPEG DC luminance Huffman table.

Constructor Detail

JPEGHuffmanTable

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

Construct and initialize a Huffman table. Copies are created of the array arguments. lengths[index] stores the number of Huffman values with Huffman codes of length index + 1. The values array stores the Huffman values in order of increasing code length.

Parameters: lengths an array of Huffman code lengths values a sorted array of Huffman values

Throws: IllegalArgumentException if either parameter is null, if lengths.length > 16 or values.length > 256, if any value in length or values is negative, or if the parameters do not describe a valid Huffman table

Method Detail

getLengths

public short[] getLengths()

Retrieve a copy of the array of Huffman code lengths. If the returned array is called lengthcount, there are lengthcount[index] codes of length index + 1.

Returns: a copy of the array of Huffman code lengths

getValues

public short[] getValues()

Retrieve a copy of the array of Huffman values, sorted in order of increasing code length.

Returns: a copy of the array of Huffman values

toString

public String toString()

Create a string representation of this JPEG Huffman table.

Returns: a string representation of this JPEG Huffman table.