fi.helsinki.cs.ohtu.mpeg2.video
Interface InverseDiscreteCosineTransform

All Known Implementing Classes:

SimpleDiscreteCosineTransform

public interface InverseDiscreteCosineTransform

This is an interface for implementations of the inverse discrete cosine transform. The exact function to be evaluated for each element of a NxN image is:

 f(x,y) = (2/N) * Sigma[u=0->N-1] Sigma[v=0->N-1] (C(u) * C(v) * F(u,v) * cosTerm1 * cosTerm2)
 ,where:
 cosTerm1 = ((2x + 1) * u * PI) / 2N
 cosTerm2 = ((2y + 1) * v * PI) / 2N
 C(x) = 1/sqrt(2) when x = 0,
        1 otherwise
 

Method Summary

double[]

transformFromFrequencySpace(int[] input, int size) Transforms one image with the IDCT.

Method Detail

transformFromFrequencySpace

double[] transformFromFrequencySpace(int[] input,
                                     int size)

Transforms one image with the IDCT.

Parameters:

input - The image to be transformed

size - The number of rows and columns in the image

Returns:

The transformed image