Efficient coding of DCT coefficients by joint position-dependent encoding
نویسندگان
چکیده
In a typical MC-DCT encoding scheme, a large portion of the bit rate is used to encode the location and amplitude information of the nonzero quantized DCT coe cients. Therefore e cient encoding of the DCT coe cients is extremely important. In this paper we describe the Joint Position-Dependent Encoding (PDE) approach to encode the DCT coe cients. Joint PDE exploits the variations in statistical properties of the runlengths and amplitudes as a function of position by introducing a set of 2-D codebooks in which each quantized DCT coe cient is assigned to one codebook in the set based on its location. Utilizing an MPEG-2 codec, we compare the bit rates using the joint PDE variable length codes (VLC's) with the bit rates produced by the MPEG-2 VLC's. We also examine how performance is a ected by the number of codebooks.
منابع مشابه
Position-dependent encoding
In typical video compression algorithms, the DCT is applied to the video, and the resulting DCT coefficients are quantized and encoded for transmission or storage. Most of the DCT coefficients are quantized to zero. Efficient encoding of the DCT coefficients is usually achieved by encoding the location and the amplitude of the non-zero coefficients. Since in typical MC-DCT compression algorithm...
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