In this paper, we present a new spatial error concealment algorithm with optimized directional decision and extrapolation. First, we employ the Sobel operator and a Hessian matrix to determine the exact direction in the cases of existing both step edges and line edges in the image. Then, with the accurately estimated direction, lost MBs are recovered by directional extrapolation pixel-by-pixel....

This paper presents a concealment method based on forward error correction (FEC) to improve speech quality deterioration caused by packet losses for CELP based coders. We applied our scheme to the standard ITU-T G729 standard speech coder to evaluate the proposed method. The perceptual evaluation of speech quality (PESQ) and enhanced modified bark spectral distortion (EMBSD) tests under various...

We propose a new multiple description method for wavelet transform coded images. The partitioning of the coefficients at the encoder is combined with concealment at the decoder to produce descriptions. An optimal concealment method for wavelet coefficients is derived based on statistical characteristics. Concealment in LL subband is treated differently and is based on its smoothness property. W...

testing as a general trait of social life has received a great deal of attention by many language teachers and scholars. throughout history, people have been tested to prove their abilities and experiences or to confirm their capacities. many authorities have said that assessment and instruction should be integrated as a single and inseparable activity which seeks to understand development by a...

The present cross-sectional study investigated whether psychological flexibility mediates the association between self-concealment and disordered eating (DE) symptoms among non-clinical college students. Data of 209 male and female participants (nfemale =165), aged 18-22 years old, were used for analyses. Self-concealment was found to be positively associated with DE symptoms (i.e., general eat...

In this paper we formulate an optimized temporal error concealment approach for H.264 based on the study of the performance of several temporal concealment features that apply to the different steps of the proposed method. Specifically we study how the concealment performance is affected by matching error measures, motion vector candidates and estimation enhancements. We show that the resulting...

When macroblocks are lost in a video decoder such as MPEG-2, the decoder can try to conceal the error by estimating or interpolating the missing area. Many different methods for this type of post-processing concealment have been proposed, operating in the spatial, frequency, or temporal domains, or some hybrid combination of them. In this paper, we show how the use of a decision tree that can a...

The error concealment is a very useful technique for real-time communication systems, such as video conferencing. In this paper, we propose an error concealment technique designated to minimize discontinuities between block boundaries in consideration of the fact that the human visual system is sensitive to discontinuities. Error concealment for each loss block is performed by surrounding regio...