Video compression makes the encoded video stream more vulnerable to the channel errors so that, the quality of the received video is exposed to severe degradation when the compressed video is transmitted over the error-prone environments. Therefore, it is necessary to apply error concealment (EC) techniques in the decoder to improve the quality of the received video. In this regard, an Adaptive Content-based EC Approach (ACBECA) is proposed in this paper, which exploits both the spatial and temporal correlations within the video sequences for the EC purpose. The proposed approach adaptively utilizes two EC techniques, including new spatial-temporal error concealment (STEC) technique, and a temporal error concealment (TEC) technique, to recover the lost regions of the frame. The STEC technique proposed in this paper is established on the basis of non-Local Means concept and tries to recover each lost macroblock (MB) as the weighted average of the similar MBs in the reference frame, whereas the TEC technique recovers the motion vector of the lost MB adaptively by analyzing the behavior of the MB in the frame. The decision on temporally or spatially reconstructing the degraded frames is made dynamically according to the content of the degraded frame (i.e., structure or texture), type of the error and also block loss rate (BLR). Compared with the state-of-the-art EC techniques, the simulation results indicate the superiority of the ACBECA in terms of both the objective and subjective quality assessments.
相似文献The development of digital technology is utilized by people to capture and share video frames. At present, rather than capturing images, people are interested in recording video footage for exploring information. Here, retrieval of video from large databases is challenging due to the continuous frame count. To overcome these challenges associated with the retrieval of video from available databases, this research proposed a likelihood-based regression approach for video processing. To improve the retrieval accuracy of video sequences, the proposed method utilizes a likelihood estimation technique integrated with a regression model. The likelihood estimate measures the pixel level roughly for estimating the pixel range, after which the regression approach measures the pixel level for transforming certainly blurred and unwanted pixels. In the proposed likelihood regression approach, the video is converted into a video frame and stored in a database. Query frames are taken into account by the generated database depending on the features which are used for a given video to be retrieved. The significant video retrieval performance obtained from the simulation results for the proposed likelihood-based regression model shows that the proposed model performs well over the other state-of-the-art techniques.
相似文献In this paper, a framework to hide privacy in video is proposed based on data hiding principals. A novel data hiding technique is proposed and implemented to hide the original frame into the in-painted one. The proposed hiding technique is carried out in the discrete wavelet transform domain of the cover video. The proposed technique is embedding video into video. Furthermore, the proposed data hiding method can blindly reconstruct the original frame from the fake one. Experimental results showed that the proposed method can successfully hide the complete frames of the original video into their corresponding in-painted ones that are as large as themselves. Simple visual inspection of the results showed that the quality of the stego-frames maintain very high (above 45 dB) while providing an acceptable visual quality for the retrieved original frames.
相似文献Closed circuit television cameras (CCTV) are widely used in monitoring. This paper presents an intelligent CCTV crowd counting system based on two algorithms that estimate the density of each pixel in each frame and use it as a basis for counting people. One algorithm uses scale-invariant feature transform (SIFT) features and clustering to represent pixels of frames (SIFT algorithm) and the other uses features from accelerated segment test (FAST) corner points with SIFT features (SIFT-FAST algorithm). Each algorithm is designed using a novel combination of pixel-wise, motion-region, grid map, background segmentation using Gaussian mixture model (GMM) and edge detection. A fusion technique is proposed and used to validate the accuracy by combining the result of the algorithms at frame level. The proposed system is more practical than the state of the art regression methods because it is trained with a small number of frames so it is relatively easy to deploy. In addition, it reduces the training error, set-up time, cost and open the door to develop more accurate people detection methods. The University of California (UCSD) and Mall datasets have been used to test the proposed algorithms. The mean deviation error, mean squared error and the mean absolute error of the proposed system are less than 0.1, 16.5 and 3.1, respectively, for the Mall dataset and less than 0.07, 5.5 and 1.9, respectively, for UCSD dataset.
相似文献Internet Protocol Television (IPTV) is an emerging network application in the internet world. One of the most reliable networks is IPTV which gives high speed for internet services. As IPTV offers many live services on user demand and it has many advantages. But still, some problem exists in the existing implementation such as degradation of quality and delay while maintaining limited frames and efficient bandwidth consumption over the network channel. The efficient bandwidth utilization is a major issue in IPTV platforms. Integrating the video processing on network platform is the challenging task in video on demand (VoD) application. This paper overcomes the drawbacks of existing IPTV by using Frame Frequency Error Optimization (FFEO) based HEVC approach which is called as U-HEVC. The FFEO method upgrades the video quality by interpolation of frames. U-HEVC delivers 50% better compression similar to the existing HEVC standard and it also provides better visual quality at half the bit rates. The Analysis of proposed U-HEVC attain better results compared to existing HEVC compression algorithms that higher number of packets get affected at different bit rate levels. In HEVC the Frame loss of 1 Mbps is 0.38%, 2 Mbps is 0.46%, 4 Mbps is 0.63% and 8 Mbps is 0.94%. When compared to the U-HEVC the Frame loss is somewhat high in HEVC. This paper presents the studies on IPTV environment based on U-HEVC using frame frequency error optimization technique.
相似文献An iterative deviation filter for fixed-valued impulse noise removal is proposed, with the aim to overcome the defects of existing filters, and further improve the denoising performance. In the proposed filter, a noise detection method based on the extreme intensity values and the deviation of neighbor pixels is proposed, i.e., the pixels with the extreme intensity and differ greatly from the mean of neighbor pixels, are identified as noises. A noise removal method based on the minimum deviation of neighbor pixels is proposed, i.e., the intensity of one neighbor noise free pixel, which is closest to the mean of neighbor noise free pixels, is used as estimated intensity of noisy pixel under consideration. Furthermore, the noise removal strategy performs iteratively and takes full advantage of the previous denoising results. Simulation results show that the proposed method has better denoising performance than the existing distinguished filters in terms of visual representation, peak signal to noise ratio and structural similarity index.
相似文献Mixed noise is a challenging noise model due to its statistical complexity. A new two-phase denoising method based on an impulse detector using dissimilar pixel counting is proposed in this paper. This method consists of two stages: detection and filtering. For the detection phase, average difference scheme is proposed to distinguish whether two neighboring pixels are similar or not, and then the number of dissimilar pixels is compared with a threshold to locate the outlier point in noisy image. An iterative framework is used for detection accuracy with the least numbers of iteration. For the filtering phase, an extended trilateral filter is used to remove the mixture of Gaussian and impulse noise, which are treated differently depending on the guidance matrix from the detection phase. Extensive experimental results demonstrate that the proposed method exhibits better noise detection capability and outperforms many existing two-phase mixed noise removal methods in both quantitative evaluation and visual quality.
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