Discrete Cosine Transform
A transform that represents a finite signal as weighted cosine basis functions and is widely used for energy compaction in compression and feature extraction.
Signal Processing Context
The Discrete Cosine Transform represents a finite sequence with cosine basis functions and concentrates correlated signal energy into a relatively small number of coefficients. Speech processing commonly applies a DCT to log Mel-filter-bank energies when forming MFCC features.
Measurement Boundary
The DCT is not interchangeable with the DFT: it uses real cosine bases and different boundary assumptions. Transform normalization also varies between implementations and must be fixed when coefficients are compared.