Adaptive wiener filter based chrominance up-sampling enhancement method for video coding

In order to improve the quality of the reconstructed video, the Wiener filter is employed in video coding to reduce the distortion caused by chrominance down/up sampling and encoding. Based on the mathematical analysis, it is verified that the distortion introduced by chrominance sampling and coding can be approximately treated as a wide sense stationary noise, which can be suppressed by the Wiener filter. Accordingly, in this paper, a two-dimensional Wiener filter is designed for reducing the noise of the reconstructed chrominance components, which further improves the video quality in the RGB color space as finally perceived by the users. Experimental results show that compared with bi-linear and inter-color up-sampling, the proposed method achieves the average gains of 0.42 dB and 0.30 dB, respectively. Meanwhile, the reconstructed video obtained by the proposed method is more close to the original one in terms of subjective quality¹.