The discrete cosine transform (DCT) is an important mathematical tool in digital image processing and many other fields.In this paper

a new Fourier analysis technique called the arithmetic Fourier transform (AFT) is used to compute DCT.The AFT of even functions is improved in this paper.The improved AFT reduces the samples needed to a half

consequently reduces the additions needed to a half.More importantly

it builds up a direct relationship between AFT and DCT.The algorithm for computing DCT using improved AFT is then deduced.This algorithm has many good performances such as it needs few multiplications (

O(N)

)

it has a unified formula and a simple structure

it can be easily performed in parallel and it is especially suitable for VLSI designing.The algorithm creates a new approach to the fast computation of DC

T.