Inverse discrete cosine transform
discrete cosine transform reconstructs a sequence from its discrete
cosine transform (DCT) coefficients. The
is the inverse of the
the inverse discrete cosine transform of
= length(x), which is the same as
The series is indexed from n
= 1 and k
= 1 instead of the usual n
= 0 and k
= 0 because MATLAB® vectors
run from 1 to N instead of from
0 to N-1.
zeros or truncates the vector
y to length
y is a matrix,
 Jain, A.K., Fundamentals of Digital Image Processing, Prentice-Hall, 1989.
 Pennebaker, W.B., and J.L. Mitchell, JPEG Still Image Data Compression Standard, Van Nostrand Reinhold, 1993, Chapter 4.