In mathematics, the discrete sine transform (DST) is a Fourier-related transform similar to the discrete Fourier transform (DFT), but using a purely real matrix. It is equivalent to the imaginary parts of a DFT of roughly twice the length, operating on real data with odd symmetry (since the Fourier transform of a real and odd function is imaginary and odd), where in some variants the input and/or output data are shifted by half a sample.
References: Wikipedia contributors, "Discrete sine transform," Wikipedia, The Free Encyclopedia, available at: http://en.wikipedia.org/w/index.php?title=Discrete_sine_transform K. R. Castleman, Digital Image Processing. Chapter 13, p.288. Prentice. Hall, 1998.
