This paper describes an HDTV/TV compatible coding method based on lapped orthogonal transform (LOT). With this method, TV signals are obtained by performing N/2‐point inverse LOT to low‐order N/2 coefficients. It is shown that the LOT domain decimation reduces the aliasing noise in TV images more efficiently than the DCT‐based method. In addition, intrafield/inter‐frame adaptive LOT coding is examined. The experimental results show that the coding efficiency of intrafield/interframe adaptive LOT coding is higher than that of intrafield/interframe adaptive DCT coding. LOT coding improves the SNR by 1 dB in fixed bit rate HDTV coding at 130 Mb/s. By using LOT as a decimation filter as well as a bit rate reduction algorithm in compatible HDTV coding, the quality of the TV images and the coding efficiency are better than with the DCT‐based method.
|ジャーナル||Electronics and Communications in Japan (Part I: Communications)|
|出版ステータス||Published - 1993|
ASJC Scopus subject areas
- コンピュータ ネットワークおよび通信