{wiki}

The type-II discrete cosine transform of $x_0,\ldots,x_{N-1}$ is
$$
Z_k=\sum_{n=0}^{N-1}x_n\cos\left(\frac{\pi}{N}\left(n+\frac12\right)k\right).
$$


Discrete cosine transform

{wiki=Discrete_cosine_transform}

The Discrete Cosine Transform (DCT) is a mathematical operation that converts a sequence of data points into a sum of cosine functions oscillating at different frequencies. It is widely used in signal processing and image compression techniques because it has properties that are beneficial for representing signals efficiently.


 Discrete cosine transform

ID: discrete-cosine-transform