org.jmol.util

Class DCT

class DCT extends Object

Field Summary
static double[]	AANscaleFactor
double[][]	divisors
double[]	DivisorsChrominance
double[]	DivisorsLuminance
static int	N DCT Block Size - default 8
static int	NN
int[][]	quantum Image Quality (0-100) - default 80 (good image / good compression)
int[]	quantum_chrominance Quantitization Matrix for chrominance.
int[]	quantum_luminance Quantitization Matrix for luminace.

Constructor Summary
	DCT(int quality) Constructs a new DCT object.

Method Summary
static void	AANscale(double[] divisors, int[] values, int quality)
static double[][]	forwardDCT(float[][] input)
void	initMatrix(int quality)
static int[]	quantizeBlock(double[][] inputData, double[] divisorsCode)

Field Detail

AANscaleFactor

private static final double[] AANscaleFactor

N

private static final int N

DCT Block Size - default 8

quantum

int[][] quantum

Image Quality (0-100) - default 80 (good image / good compression)

quantum_chrominance

private int[] quantum_chrominance

Quantitization Matrix for chrominance.

quantum_luminance

private int[] quantum_luminance

Quantitization Matrix for luminace.

Constructs a new DCT object. Initializes the cosine transform matrix these are used when computing the DCT and it's inverse. This also initializes the run length counters and the ZigZag sequence. Note that the image quality can be worse than 25 however the image will be extemely pixelated, usually to a block size of N.

Parameters: quality The quality of the image (0 worst - 100 best)

Method Detail

AANscale

private static void AANscale(double[] divisors, int[] values, int quality)

forwardDCT

static double[][] forwardDCT(float[][] input)

initMatrix

private void initMatrix(int quality)

quantizeBlock

static int[] quantizeBlock(double[][] inputData, double[] divisorsCode)