Structurally regular integer discrete cosine transform for low-bit-word-length coefficients
This paper presents an IntDCT with only dyadic values such as k/2n (k, n 6 N). Although some IntDCTs have been proposed, they are unsuitable for lossless-to-lossy image coding in low-blt-word-length (coefficients). First, the proposed M-channel lossless WHT (LWHT) can be constructed by only (log2 M)-blt-word-length and has structural regularity. Then, our 8-channel IntDCT keeps good coding performance even In low-blt-word-length because LWHT, which Is main part of IntDCT, can be implemented by 3-bit-word-length. Finally, our method is validated In lossless-to-lossy image coding.