Transforms to and from the Frequency Domain - Digital Video and Audio Broadcasting Technology - page 100

The formulas of the Discrete Cosine Transform (DCT) and the Discrete
Sine Transform (DST) are:

1

Π k ( z + )

= N
z

∑ −
=

1 N

∑ −
=

1

Π zk

2

F f cos( ); F = f sin( );

k z k z

N N

0 z 0

cos(0)
cos(0.5x)
cos(x)
cos(1.5x)
cos(2x)

Fig. 6.8. Discrete Cosine Transform (DCT)

sin(0.5x)
sin(x)
sin(1.5x)
sin(2x)
sin(2.5x)

Fig. 6.9. Discrete Sine Transform (DST)

The DCT supplies, in the time domain, the amplitudes of the cosine sig-
nals from which the time interval analyzed can be assembled. The zero co-
efficient corresponds to the DC component of the signal segment. All the