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(a) nNN forward DCT transform matrix F. Snother function that uses F to perform the DCT forward transform for an arbitrary image of size NN (see preparation). An NN image G can be transformed using the matrix F as follows T=FGFT where T is an NN matrix called the transform of G. When the elements of F are computed using the DCT F[i,j]=f(i,j)=N1cos(2N(2j+1)i)N2cos(2N(2j+1)i)i=0,j=0,1,,N1i=1,2,,N1,j=0,1,,N1 then equation (1) is called the forward DCT of G. Noting that the variable i (the row number) in Equation (2) represents frequency, it can be seen that each row of the transform matrix F represents one of the one-dimensional DCT basis vectors