discrete cosine transform

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discrete cosine transform (DCT) A mathematical operation that analyzes an arbitrary waveform into a summation of cosine functions: C(u) = √∑N-1x=0f(x)cos(2x+1)uπ/2N

where the waveform f(x) is approximated by N samples at x = 0,1,…N–1.

Discrete cosine transforms find application in image-compression techniques, for example in JPEG.