Efficient Algorithm and System Architecture for the Suppression of MPEG Artifacts

This paper presents i) the development of an algorithm that enhances the visual quality of MPEG compressed image sequences and ii) the design of a system architecture for implementation of the algorithm in a battery powered handheld device. In the spatial domain a combination of classification, Kalman smoothing and sharpening filtering has been used to suppress blocking, ringing and blurring artifacts. In the temporal domain a Kalman filter in conjunction with a motion detection method has been used to suppress temporal flicker and mosquito noise. Furthermore, a system architecture has been designed at two levels of granularity. At the coarse level, the SpecC methodology has been used to determine an overall system architecture consisting of a GPP and a hardware accelerator. At the fine level, time constrained scheduling has been used to find a suitable architecture for the accelerator data-path. Several optimization techniques have been applied to the accelerator in order to minimize the area consumption. A subjective and quantitative evaluation shows that the algorithm improves the visual quality of the compressed image sequences. The final architecture of the accelerator consists of 6 register files, 1 register, 3 multipliers, 2 adders, 1 subtracter, 1 divider, 1 comparator and 1 magnitude calculator