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An efficient coding algorithm for depth map images and videos, based on view synthesis distortion estimation, is proposed in this work. We first analyze how a depth error is related to a disparity error and how the disparity vector error affects the energy spectral density of a synthesized color video in the frequency domain. Based on the analysis, we propose an estimation technique to predict the...
In High Efficiency Video Coding (HEVC), advanced motion vector prediction (AMVP) is adopted to predict current motion vector by utilizing a competition-based scheme from a given candidate set, which include both the spatial and temporal motion vectors. In order to enhance the practicability of the AMVP, a simplified AMVP is proposed. Firstly, by analyzing the importance of the spatial and temporal...
Pixel-domain analysis methods are widely adopted in background modeling, some of which are not only concerned by academia but also coming into view of industry. However, as the increasing data volume of video, how to process and analysis videos in a fast and effective way has still been an intractable problem in practical applications. Under this circumstance, surveillance video analysis in the compressed...
Video transcoding is an efficient way to reduce the bitrate or convert the format of the original video stream to meet the requirements of different applications and various channel capacity. In this paper, we propose a fast multiview video transcoder (MVT) for bitrate reduction. Different from the H264 transcoder, the inter-view prediction information in the input video stream is utilized to reduce...
Detecting pedestrians with disability in surveillance videos is practical for the implementation of automated alert/assistance technology. This paper presents a novel approach for the dimensionality reduction which employs sparse representation to improve the generalization capability of a classifier. To characterize pedestrian with disability, we create directional maps by determining the dominant...
Multiple Maximum scatter difference (MMSD) discriminant criterion is an effective feature extraction method that computes the discriminant vectors from both the range of the between-class scatter matrix and the null space of the within-class scatter matrix. However, singular value decomposition (SVD) of two times is involved in MMSD, making this method impractical for high dimensional data. In this...
We propose a new scheme that exploits characteristics of motion vectors combined with luminance contrast to automatically detect human attention regions of interest (HAROIs) in every I-frame or intra-coded blocks in a group of pictures (GOP). These HAROIs can then be used for adaptive quantization. Motion vectors information is collected before the encoding phase. Our ultimate goal is to obtain a...
In video coding standard, motion estimation (ME) always plays an important role in reducing temporal redundancies at the expense of higher computational complexity. Many fast ME algorithms have been proposed to reduce the coding complexity. Some papers focus on applying specific search patterns to reduce the search points within a fixed search range (SR). But there are only a few of them trying to...
Inferring user search goals for a query can be very useful in improving search engine relevance and user experience. Although the research on analyzing user goals or intents for text search has received much attention, little has been proposed for image search. In this paper, we propose a novel approach to infer user search goals in image search by mining search engine query logs with semi-supervised...
Hierarchical transforms are widely used in image and video coding to produce multilevel decomposition of signals. After applying these transforms, same level signals are typically uncorrelated. However, there is often still significant cross level information. Traditionally, this cross-level information is exploited at the entropy coding step, but not at the transform step. The main contribution of...
Advanced motion vector prediction (AMVP) is one of the most important inter prediction coding tools adopted in the state-of-the-art HEVC coding standard, which does great effect on the coding efficiency. However, the current AMVP design is highly sequential and thus restricts the throughput both on the encoder and the decoder sides. To facilitate the parallel processing and enlarge the throughput,...
Higher-order motion models were introduced in video coding a couple of decades ago, but have not been widely used due to both difficulty in parameters estimation and their requirement of more side information. Recently, researchers have put them back into consideration. In this paper, the affine motion model is employed in SKIP and DIRECT modes to produce a better prediction. In affine SKIP/DIRECT,...
Intra prediction is an important part of intra-frame coding. A number of approaches have been proposed to improve intra prediction including a general linear prediction approach in which a weighted sum of all available neighbor pixels is used to predict each block pixel. An important part of this approach is the determination of the used weights. One method to determine the weights is to use the least-squares...
We present a novel learning-based method for single image super-resolution (SR). Given a single input low-resolution (LR) image (and its image pyramid), we propose to learn context-specific image sparse representation, which aims at modeling the relationship between low and high-resolution image patch pairs of different context categories in terms of the learned dictionaries. To predict the SR image,...
Variational method is a well-established technique that solves for a dense field, which is widely adopted in the estimation of optical flow field and remains the most accurate technique to date. However, one of the problems in variational method lies in that it is optimized in an iterative manner towards a single objective, but local details may be compromised owing to the “big picture”. In this paper,...
In this paper, we focus on recovering a 3-D depth map from a single image via ground-vertical boundary analysis. First, we generate a ground map from the input image based on the spectral matting method, followed by a spatial geometric inference. After that, we derive the depth information for the ground-vertical boundaries. Unlike conventional approaches which generally use plane models to reconstruct...
In this paper, we investigate and propose a novel prediction model for lossless image coding in which the optimal correlated prediction for block of pixels are simultaneously obtained in the sense of the least code length. It not only utilizes the spatial statistical correlation for the optimal prediction directly based on 2-D contexts, but also formulates the data-driven structural interdependencies...
This paper presents a novel 2D-TO-3D conversion approach from a monoscopic 2D image sequence. We propose a particle filter framework for recursive recovery of point-wise depth from feature correspondences matched through image sequences. We formulate a novel 2D dynamics model for recursive depth estimation with the combination of camera model, structure model and translation model. The proposed method...
In Wyner-Ziv video coding architectures, the available bit budget to each GOP is shared between key frames and Wyner-Ziv frames. In this work, we first propose a model to express the relationship between quantization step size of key and WZ frames based on their motion activity. Then we apply this model to propose an adaptive algorithm adjusting the quantization step size of key and WZ frames to achieve...
A theoretical analysis on interframe predictive coding is presented in which special attention is paid on two issues that are practically important. First, the displacements between the target and reference images are usually given with limited accuracy due to quantization. Second, when the displacements are provided in subpixel accuracies, interpolation between the pixels is necessary to produce...
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