Motion field estimation by vector rational interpolation for error concealment purposes

Abstract

A study on the use of vector rational interpolation for the estimation of erroneously received motion fields of an MPEG-2 coded video bitstream has been performed. Four different motion vector interpolation schemes have been examined using motion information from available top and bottom adjacent blocks since left or right neighbours are usually lost. The presented interpolation schemes are capable of adapting their behaviour according to neighbouring motion information. Simulation results prove the satisfactory performance of the novel nonlinear interpolation schemes and the success of their application to the concealment of predictively coded frames. The motion vector rational interpolation concealment method proves to be a fast method, thus adequate for real-time applications.

Video Error Concealment by Integrating Greedy Suboptimization and Kalman Filtering Techniques

“…The sequences of and along the whole slice/GOB can then be modeled as the following two auto-regressive processes, respectively (18) (19) where and are two space-invariant constants that describe the relationship between MVs of two adjacent MBs. Comparing these two equations with (11), corresponds to the state variable and corresponds to the state transition matrix . The noise terms and are assumed to be normally distributed and have a zero mean as follows: (20) where is the variance.…”

“…The estimated MV can be obtained easily from the previous frame at the same MB location, or by assuming zero MV. Other more sophisticated methods of estimating MVs of corrupted MBs are proposed in [11]- [13]. Generally, error concealment techniques based on temporal information are successful if high correlations exist in the temporal domain.…”

Auto Regressive Model and Weighted Least Squares Based Packet Video Error Concealment

“…The well known Boundary matching algorithm (BMA) proposed in [7] selected the MV that minimizes the total variation between the internal boundary and the external boundary of the reconstructed block as the optimal one to recover the corrupted block. There are also some more sophisticated algorithms [8][9][10][11][12] to obtain better MVs for the corrupted blocks. All these methods attempt to find the best MV in the previous quarter-pel resolution frame, which are interpolated by the fixed filter tap.…”

Vector Rational Interpolation Schemes for Erroneous Motion Field Estimation Applied to MPEG-2 Error Concealment

“…In a first approach, four different interpolation schemes have been considered [18], differing only in the neighboring pairs of available motion vectors used, that is, in which direction the interpolation is applied, as is shown in (7) where , and coefficients , , , are defined by (8) In (8), denotes the vector norm and is a positive constant that controls the degree of nonlinearity of the rational filter.…”