In the studies related to multiple description coding (MDC), applying zero padding not only
improves the spatial correlation between descriptions but also increases their sizes. However, as we
pad more zeros, the spatial correlation does not improve linearly. Therefore, the distortion is not
reduced as the same amount when the size increases. In this paper, we focus on how to efficiently find
an acceptable trade-off between the number of padded zeros and the increase of distortion in MDC. In
this paper, we propose two distortion estimations for MDC with zero padding based on spatial
quincunx distribution, which are standard deviation for distortion estimation and triangular linear
approximation distortion estimation (TLA-DE) to efficiently calculate the distortion for the number of
padded zeros atthe horizontal direction. In order to search for the acceptable number of padded zeros,
we propose two search methods, Naïve Search and Best Division Search, which are both based on the
proposed rate-distortion trade-off indicator. Our experiments result show that the worst error of
distortion estimation by TLA-DE is up to 18%, but the average is 5.5% with 95% confidence level.
The executing time of best division search is about two times faster than that of naïve search for 11 test
sequences. To sum up, we confirm that the acceptable trade-off between rate and distortion in low
computational complexity can be found by using the best division search on TLA-DE.
關聯:
Journal of Applied Science and Engineering 19(2), pp.229-239