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

All Known Implementing Classes:

SimpleDiscreteCosineTransform

public interface DiscreteCosineTransform

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

 F(u,v) = (2/N) * C(u) * C(v) * Sigma[x=0->N-1] Sigma[y=0->N-1] (f(x,y) * 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[]

transformToFrequencySpace(int[] input, int size) Transforms one image with the DCT.

Method Detail

transformToFrequencySpace

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

Transforms one image with the DCT.

Parameters:

input - The image to be transformed

size - The number of rows and columns in the image

Returns:

The transformed image