Digital Signal Processing/Discrete Cosine Transform

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Discrete Cosine Transform in dsp[edit | edit source]

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.

Inverse DCT[edit | edit source]

Computing DCT[edit | edit source]

Uses of DCT[edit | edit source]

The JPEG process is a widely used form of lossy image compression that centers around the Discrete Cosine Transform. The DCT works by separating images into parts of differing frequencies.

Further reading[edit | edit source]