# Digital Signal Processing/Discrete Cosine Transform

From Wikibooks, open books for an open world

## Contents

## Discrete Cosine Transform in dsp[edit]

The **Discrete Cosine Transform** (DCT) is a transform that is very common when encoding video and audio tracks on computers. Many "codecs" for movies rely on DCT concepts for compressing and encoding video files. The DCT can also be used to analyze the spectral components of images as well. The DCT is very similar to the DFT, except the output values are all real numbers, and the output vector is approximately twice as long as the DFT output. It expresses a sequence of finite data points in terms of sum of cosine functions.