Open AccessImproved algorithm for detecting zero‐quantised discrete cosine transform coefficients in H.264/AVC (revised version)
Author(s) -
Wang LiLi,
Siu WanChi
Publication year - 2013
Publication title -
iet image processing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.401
H-Index - 45
eISSN - 1751-9667
pISSN - 1751-9659
DOI - 10.1049/iet-ipr.2011.0355
Subject(s) - discrete cosine transform , algorithm , zero (linguistics) , computer science , artificial intelligence , image (mathematics) , philosophy , linguistics
In this study, an efficient approach for detecting zero‐quantised discrete cosine transform (DCT) coefficients for video coding is developed. Compared with conventional detection methods of zero‐quantised DCT coefficients used in H.264/AVC, the proposed algorithm has two major features. First, a new classification of patterns for DCT, quantisation, inverse quantisation and inverse discrete cosine transform processes is proposed. By taking a zigzag scanning order into the classification, the quantised DCT coefficients can be coded efficiently. Second, the thresholds for detecting zero‐quantised DCT coefficients are determined by combining the Gaussian distribution with a theoretical analysis of the DCT and quantisation in H.264/AVC. Experimental results show that the proposed algorithm achieves an average timesaving of more than 40% compared with the algorithm in reference software JM12.2 of H.264/AVC. When compared with other algorithms in the literature, it also gives the best performance in terms of both rate‐distortion and time saving.