Discrete　cosine　transforms　(DCT)　have　been　the　mainstay　of　image　signal　processing.　In　this　paper　a　practical,　efficient　Asymmetric　DCT　(ADCT)　is　proposed.　For　2D-DCT,　ADCT　implements　the　row　computation　differently　in　concept　from　column　computation.　A　SIMD　and　VLIW　oriented　architecture　for　ADCT　is　further　proposed　to　achieve　about　20%　speed　improvement　over　the　fastest　known　VLIW　oriented　DCT.　Compared　with　Loeffler＇s　algorithm,　the　architecture　saves　more　than　half　the　arithmetic　calculations.　When　applied　to　VLIW,　it　is　more　efficient　and　regular　than　Feig＇s　algorithm.　©　2005　IEEE.