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In multiview video coding (MVC), disparity-compensated prediction (DCP) exploits the correlation among different views. A common approach is to use block-based motion-compensated prediction (MCP) tools to predict the disparity effect among different views. However, some regions in different views may have various deformations due to nonconstant depth. Thus, performance of DCP is not satisfactory with the simple translational model assumed in conventional block-based MCP tools. Previous attempts to achieve better disparity prediction were usually too complex for practical use. In this paper, horizontal scaling and shearing (HSS) effects are investigated to increase interview prediction accuracy for stereo video. HSS deformations are common among images of horizontally aligned views, due to horizontal and vertical flat surfaces that are not parallel with projection image planes. To achieve HSS-based DCP with minimal complexity, an efficient subsampled block-matching technique is adopted and integrated into MVC extension of H.264/AVC in stereo profile. Affine parameters estimation and additional frame buffers are not required and the overall increase of computational complexity and memory requirements are moderate. Experimental results show that the new technique can achieve up to 5.25% bitrate reduction in interview prediction using JM17.0 reference software implementation. [ABSTRACT FROM PUBLISHER]

In this study, we evaluate fast motion estimation (ME) techniques in the context of a JPEG 2000-based video coding system for surveillance-type videos. The authors have designed a low-complexity algorithm, called block-selective ME, which restricts block matching to certain frames or blocks containing high motion. They compare the performance of our block-selective ME algorithm to a frame-based approach and to a standard fast-motion algorithm (three-step search (TSS)). For surveillance-type videos, the authors show that the block-selective approach achieves the peak signal to noise ratio (PSNR) quality of a full ME scheme for; 70-80% of the blocks. Moreover, this approach delivers a higher visual image quality compared to TSS, if the computational load for a set number of blocks were fixed. The authors have integrated our block-selective approach into different coders (H.264 and MPEG-2) and show that our approach is an outstanding alternative to fast-ME in low-complexity environments. [ABSTRACT FROM AUTHOR]

While many recent international video coding standards, especially H.264/MPEG-4 AVC, leverage block size adaptivity in motion estimation, the rate-distortion boundary can be pushed further by allowing even more freedom in the partitioning process of inter pictures. Adaptive-shape partitioning, which allows blocks to be partitioned along a straight line that runs through the block at a freely chosen angle and position, complements the regular subblock partitioning, allowing the encoder to better adapt to the local characteristics of the motion activity in a video sequence. However, the technique demands excessive encoder resources to exhaust the large search space. This paper is the result of an investigation into the relative rate-distortion importance of the various adaptive-shape modes, both in terms of the angle of the partition boundary and of its location within a block. We find that a significant reduction of the search space with a factor of up to 40 can be accomplished, while retaining 50 to 90% of the compression gain obtained in the state of the art. This allows encoders to operate at much lower complexity levels and also reduces the signaling overhead associated with adaptive-shape partitioning. Based on our observations, we formulate a number of approaches to trade off compression performance against encoder complexity. Furthermore we discuss the use of various schemes of overlapping motion estimation along the partition boundary, an aspect which is currently left unaddressed in the literature on adaptive-shape partitioning. We introduce the use of shape-adaptive transforms for the motion compensated signal, to avoid the condition that arises with adaptive-shape partitioning where a partition boundary lies inside a transform block. The result is a reduction in ringing artifacts while maintaining objective quality. [ABSTRACT FROM AUTHOR]

Abstract: Block based transform coding is one of the most popular techniques for image and video compression. However it suffers from several visual quality degradation factors, most notably from blocking artifacts. The subjective picture quality degradation caused by blocking artifacts, in general, does not agree well with the popular objective quality measure such as PSNR. A new image quality assessment method that detects and measures strength of blocking artifacts for block based transform coded images is proposed. In order to characterize the blocking artifacts, we utilize two observations: if blocking artifacts occur on the block boundary, the pixel value changes abruptly across the boundary and the same pixel values usually span along the entire length of the boundary. The proposed method operates only on a single block boundary to detect blocking artifacts. When a boundary is classified as having blocking artifacts, corresponding blocking artifact strength is also computed. Average values of those blocking artifact strengths are converted into a single number representing the subjective image quality. Experiments on various JPEG compressed images with various bit rates demonstrated that the proposed blocking artifacts measuring value matches well with the subjective image quality judged by human observers. [Copyright &y& Elsevier]

According to constructivist theory a film cues us to apply a variety of schemata in mentally constructing a narrative and the diegetic world in which it takes place. But to what extent and with what degree of precision do we mentally construct time, space, causality, and the characters when we watch a film? We are not aware of the real world and our immediate environment much in excess of what our interests, needs, and desires are in any given situation. Similarly, we do not conceive of a complete fictional world when watching a film. Rather, a film cues us to fill in to the extent and with a precision that is relevant to our attempts at making sense of what is happening, often as focalized in terms of character interest. The cueing takes place through an interplay of what Thompson (1988) has defined as the realistic and the aesthetic background construction. This article outlines how this interplay functions to override apparent discrepancies in the material on the one hand, and to produce a variety of aesthetic effects on the other hand. Von Trier's Antichrist serves as an example of how the partial blocking of the filling in function can serve intriguing aesthetic purposes. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a method to integrate linear horizontal, vertical and right-angled scene structures into the bundle adjustment of image sequences. An increasing number of airborne image acquisition systems is available and equipped with non-metric small- or medium-frame cameras and no or insufficiently accurate INS devices. In cases where the data is to be used for the production of geo-spatial data, where a certain accuracy and precision is required, an indirect sensor orientation, possibly including self-calibration, needs to be performed. The idea which led to the presented approach is to reduce the number of GCPs necessary for this task by applying the mentioned scene structures. The method directly uses the linear structures, visible at man-made objects as fictive observations within the adjustment, while self-calibration of intrinsic camera parameters and lens distortion is included as well. Experiments with two datasets demonstrate that, through this method, only limited GCP information is required to obtain satisfactory results. In fact, in one experiment using oblique images, several scene constraints were provided and only the datum was defined by ground control. The residuals at check points from this setup were similar to the traditional case where several well-distributed GCPs were available in the scene. In the second experiment the ability of this approach to support the bundle adjustment was shown for a UAV dataset. Although no GCP and camera calibration information was available, the visual inspection of adjusted object points and the residuals at horizontal structures confirmed the ability of the method to align an image block with the structure, as embodied in the defined scene constraints. Despite the convincing outcome of the experiments, it needs to be mentioned that some manual work is still involved in defining the constraints. In future work the issue of automation will be addressed. [Copyright &y& Elsevier]

frame interpolation algorithm for the application of low-bit-rate video coding is proposed in this paper. The global motion vectors are first estimated by computing global sum of absolute differences between frames. Then the block motion estimation is carried out according to the modified weighted correlation index criteria. The estimation is further adjusted around the moving object based on the modified weighted correlation index criteria but with a smaller factor k so that the global motion estimation is less influential to the movement vector estimation for the moving objects. Finally the motion estimation outliers are determined by the Box-and-Whisker analysis, and removed by two methods. Method 1 redoes the bi-directional estimation with a larger factor k; Method 2 computes the movement vectors of the outliers using neighboring movement vectors. The experiments showed that the proposed method can improve the peak signal to noise ratio for four test video sequences. Visual inspection also shows better frame interpolation quality. [ABSTRACT FROM AUTHOR]

The article examines the interrelation of the themes of theatricality and conspiracy in the films of French director Jacques Rivette. The author discusses the manner in which both theatricality and conspiracy generate an exploration of the notion of play and its dramatic uses in the cinema. The author addresses the structural and spatial implications of Rivette's interest in conspiracy. The influence of French filmmaker Louis Feuillade on Rivette's work is talked about. Films examined in the article include "Paris nous appartient," "La Religieuse," and "L'amour fou."

This paper presents a new video coding technique using multiwavelet transform and multi-stage vector quantization. Three types of redundancies that are common in video sequence are spatial, temporal and psycho visual redundancies. In this work, the spatial redundancy in the video is minimized using multiwavelet transform. The transform coefficients are then quantized using multi-stage vector quantization scheme. Motion estimation/ compensation reduce temporal redundancy by exploiting interpicture correlation. Kite cross diamond search is the block matching algorithm used for motion estimation. The objective is to develop low bit rate video coder with acceptable visual quality. The performance of the proposed method is compared with wavelet based video coder. [ABSTRACT FROM AUTHOR]

Abstract: In this paper a novel method is presented to detect moving objects in H.264/AVC [T. Wiegand, G. Sullivan, G. Bjontegaard, G. Luthra, Overview of the H.264/AVC video coding standard, IEEE Transactions on Circuits and Systems for Video Technology, 13 (7) (2003) 560–576] compressed video surveillance sequences. Related work, within the H.264/AVC compressed domain, analyses the motion vector field to find moving objects. However, motion vectors are created from a coding perspective and additional complexity is needed to clean the noisy field. Hence, an alternative approach is presented here, based on the size (in bits) of the blocks and transform coefficients used within the video stream. The system is restricted to the syntax level and achieves high execution speeds, up to 20 times faster than the related work. To show the good detection results, a detailed comparison with related work is presented for different challenging video sequences. Finally, the influence of different encoder settings is investigated to show the robustness of our system. [Copyright &y& Elsevier]

Abstract  The Guard Channel Scheme (GCS) and Handoff Queueing Scheme (HQS) are the popular and practical strategies to prioritize handoff calls in wireless cellular networks. A key issue of giving handoff calls the higher priority is how to achieve a tradeoff among the handoff call blocking probability, new call blocking probability and handoff delay. This paper extends GCS and HQS and presents an efficient handoff scheme that dynamically manages the channels reserved for handoff calls depending on the current status of the handoff queue. A three-dimensional Markov model is developed to analyze the performance of this scheme and investigate the desirable performance tradeoff. The Poisson process and Markov-Modulated-Poisson-Process (MMPP) are used to model the arrival processes of new and handoff calls, respectively. The accuracy of this model is evaluated through the extensive comparison of the analytical results to those obtained from discrete-event simulation experiments. Performance measures in terms of the mean number of calls in the system, aggregate response time, aggregate call blocking probability, handoff call blocking probability, new call blocking probability and handoff delay are evaluated. The analytical model is used to investigate the effects of the number of channels originally reserved for handoff calls, the number of dynamic channels, and the ratio of the rate of handover calls to the aggregate arrival rate on the system performance. [ABSTRACT FROM AUTHOR]

True motion estimation is necessary for deinterlacing, frame-rate conversion, and film judder compensation. There have been several block-based approaches to find true motion vectors by tracing minimum sum-of-absolute-difference values by considering spatial and temporal consistency. However, the algorithms cannot find robust motion vectors when the texture of objects is changed. To find the robust motion vectors in the region, a recursive vector selection scheme and an adaptive weighting parameter are proposed. Previous frame vectors are recursively averaged to be utilized for motion error region. The weighting parameter controls fidelity to input vectors and the recursively averaged ones, where the input vectors come from the conventional estimators. If the input vectors are not reliable, then the mean vectors of the previous frame are used for temporal consistency. Experimental results show more robust motion vectors than those of the conventional methods in time-varying texture objects. © 2008 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 18, 265–275, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). [ABSTRACT FROM AUTHOR]

Edge is an important feature in video classification which finds applications in video representation and coding. In H.264/AVC, intra-prediction mode decision (a computationally intensive process) is based on the orientation of the edges in the macroblock. In this paper, we first investigate the difference properties derived from three coefficients in the non-normalized Haar transform (NHT) domain and present a fast and efficient method to classify block edge using these properties. The proposed method significantly reduces the number of computational operations in the edge models determination with no multiplications and less addition operations. The use of edge classification for fast intra-prediction mode decision in H.264/AVC video coding is then presented. The experimental results show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Frame rate up-conversion is a postprocessing tool to convert the frame rate from a lower number to a higher one. It is a useful technique for a lot of practical applications, such as display format conversion, low bit rate video coding and slow motion playback. Unlike traditional approaches, such as frame repetition or linear frame interpolation, motion-compensated frame interpolation (MCFI) technique is more efficient since it takes block motion into account. In this paper, by considering the deficiencies of previous works, new criteria and coding schemes for improving motion derivation and interpolation processes are proposed. Next, for video coding applications, adaptive frame skip is executed at the encoder side to maximize the power of MCFI so that the quality of interpolated frames is guaranteed. Experimental results show that our proposal effectively enhances the overall quality of the frame rate up-converted video sequence, both subjectively and objectively. [ABSTRACT FROM AUTHOR]

Abstract  This paper describes novel transcoding techniques aimed for low-complexity MPEG-2 to H.264/AVC transcoding. An important application for this type of conversion is efficient storage of broadcast video in consumer devices. The architecture for such a system is presented, which includes novel motion mapping and mode decision algorithms. For the motion mapping, two algorithms are presented. Both efficiently map incoming MPEG-2 motion vectors to outgoing H.264/AVC motion vectors regardless of the block sizes that the motion vectors correspond to. In addition, the algorithm maps motion vectors to different reference pictures, which is useful for picture type conversion and prediction from multiple reference pictures. We also propose an efficient rate-distortion optimised macroblock coding mode decision algorithm, which first evaluates candidate modes based on a simple cost function so that a reduced set of candidate modes is formed, then based on this reduced set, we evaluate the more complex Lagrangian cost calculation to determine the coding mode. Extensive simulation results show that our proposed transcoder incorporating the proposed algorithms achieves very good rate-distortion performance with low complexity. Compared with the cascaded decoder-encoder solution, the coding efficiency is maintained while the complexity is significantly reduced. [ABSTRACT FROM AUTHOR]

Abstract  In this paper, a temporal resolution reduction transcoding method that transforms an MPEG-4 video bitstream into an H.264 video bitstream is proposed. The block modes and motion vectors in the MPEG-4 bitstream are utilized in the H.264 encoder for the block mode conversion and motion vector interpolation methods. Four types of motion vector interpolation methods are proposed in order to avoid the use of brute-force motion estimation in H.264. According to the experimental results, the proposed methods achieve a 3∼4 times improvement in the computational complexity compared to the cascade pixel-domain transcoding method, while the PSNR (peak signal to noise ratio) is degraded by 0.2∼0.9 dB depending on the bitrates. [ABSTRACT FROM AUTHOR]

Characterized by their distinctive motion patterns, temporal textures are natural phenomenon exhibiting spatio-temporal regularity with indeterminate spatial and temporal extent. This paper presents a real-time motion-based temporal texture characterization technique for the first time using block-based motion measures with very high classification accuracy against the popular opinion that such an accurate characterization is only possible using pixel-based measures. Finding an optimal weight ratio between space and time domain features where the accuracy of this block-based technique peaks has been the essence of this success. Computational complexity analyses and classification results clearly demonstrate the capability of the proposed technique in producing comprehensive classification results comparable to the best pixel-based technique with overwhelming reduction in computational complexity. [ABSTRACT FROM AUTHOR]

The author discusses techniques of filmmaking that limit the potential of motion pictures. He suggests that the format utilized to write screenplays homogenizes ideas and writing styles and leads to the domination of dialogue over visual storytelling. He comments that motion picture directors such as Wong Kar-Wai and Mike Leigh use improvisation in their motion pictures. He suggests filmmakers should not be constrained by set design and the blocking of scenes. He comments that photographic coverage of scenes can add to the bureaucratization of motion pictures.

Little attention has been paid to an impairment common in motion-compensated video compression: the addition of high-frequency (HF) energy as motion compensation displaces blocking artifacts off block boundaries. In this paper, we employ an energy-based approach to measure this motion-compensated edge artifact, using both compressed bitstream information and decoded pixels. We evaluate the performance of our proposed metric, along with several blocking and blurring metrics, on compressed video in two ways. First, ordinal scales are evaluated through a series of expectations that a good quality metric should satisfy: the objective evaluation. Then, the best performing metrics are subjectively evaluated. The same subjective data set is finally used to obtain interval scales to gain more insight. Experimental results show that we accurately estimate the percentage of the added HF energy in compressed video. [ABSTRACT FROM AUTHOR]

In this letter, we demonstrate that the generalization properties of a neural network (NN) can be extended to encompass objects that obscure or segment the original image in its foreground or background. We achieve this by piloting an extension of the noise injection training technique, which we term excessive noise injection (ENI), on a simple feedforward multilayer perceptron (MLP) network with vanilla backward error propagation to achieve this aim. Six tests are reported that show the ability of an NN to distinguish six similar states of motion of a simplified human figure that has become obscured by moving vertical and horizontal bars and random blocks for different levels of obscuration. Four more extensive tests are then reported to determine the bounds of the technique. The results from the ENI network were compared to results from the same NN trained on clean states only. The results pilot strong evidence that it is possible to track a human subject behind objects using this technique, and thus this technique lends itself to a real-time markerless tracking system from a single video stream. [ABSTRACT FROM AUTHOR]

This paper describes a new technique for reducing the blockiness that results from using the reduced-resolution update (RRU) video coding tool. In RRU coding, full resolution prediction error residuals are downsampled and coded at a reduced spatial resolution. In previous versions of RRU, such as that defined in Annex Q of the H.263 standard, each block of prediction errors is processed without using samples from any neighboring blocks. This can lead to severe blockiness in the decoded picture. To reduce this blockiness 11.263 Annex Q RRU increases the deblocking filter strength to the maximum value. In the new technique presented here, referred to as RRU+, the downsampling and interpolation filters use residuals from neighboring blocks to prevent the blockiness that results from RRU. Experimental results comparing RRU+, RRU with normal deblocking filter strength (referred to simply as RRU in this paper), and RRU with maximum deblocking filter strength are presented. These results show that, while RRU+ and RRU with maximum deblocking strength both eliminate the blocking artifacts associated with RRU, RRU+ provides better peak signal-to-noise ratio (PSNR) performance than RRU, whereas RRU with maximum deblocking strength degrades the PSNR performance compared to RRU. Results comparing H.264 with RRU/RRU+ are also presented and the effectiveness of RRU/RRU+ as a tool for improving coding efficiency is discussed. [ABSTRACT FROM AUTHOR]

Block-based motion estimation is widely used in video compression for exploiting video temporal redundancy. Although effective, the process is arguably the most computationally intensive part of a typical video encoder. To speed up the process, a large number of fast block-matching algorithms (BMAs) have been proposed for motion estimation by limiting the number of search locations or simplifying the measure of match between the two blocks under comparison. In this paper we propose a new BMA that measures the match by using such features as block sum and block variance, which can be easily computed using integral frame attributes. Experimental results show that the proposed BMA can reduce the computational complexity notably and achieve compression performance very close to that of existing BMAs using conventional block-matching measures. [ABSTRACT FROM AUTHOR]

Block-Wise processing of motion compensated interlaced-to-progressive conversion (MC-IPC) can cause spurious errors that degrade converted image quality significantly. This paper presents a novel IPC method based on motion adaptive IPC (MA-IPC) with its adaptation assisted by the motion compensation. The motion adaptation is performed with respect to a motion selected from a limited set based on the accuracy evaluated with a reduced and overlapped block. The use of the reduced and overlapped blocks makes evaluation of the accuracy more precise, and implementation less costly. The motion adaptation structure ensures that any possible error occurs pixel-wise so that the block-wise spurious errors can be eliminated. The estimation of the motion is performed efficiently with data already available for the motion adaptation. The proposed motion compensation assisted MA-IPC method provides image quality similar to the MC-IPC, for those images, the MC-IPC offers significant improvement over the MA-IPC, yet at considerably lower computational and implementation costs. [ABSTRACT FROM AUTHOR]

This paper presents a new block matching motion estimation algorithm and its VLSI architecture design. The pro- posed global elimination algorithm (GEA) was derived from successive elimination algorithm (SEA), which can skip unnecessary sum of absolute difference (SAD) calculation by comparing minimum SAD with subsampled SAD (SSAD). Our basic idea is to separate the decision of early termination and SAD calculation for each candidate block to make data flow more regular and suitable for hardware. In short, we first compare the rough characteristics of all candidate blocks with the current block (SSAD). In turn, we select several best roughly matched candidate blocks to re-compare them with the current block by using detailed characteristics (SAD). Other features of GEA include fixed processing cycles, no initial guess, and high video quality (almost the same as full search). Unlike other fast algorithms, the mapping of GEA to hardware is very simple. We proposed an architecture that is composed of a systolic part to efficiently compute SSAD, an adder tree to support both SSAD and SAD calculations, and a comparator tree to avoid expensive sorting circuits. Simulation results show that our design is much more area efficient than many full-search architectures while maintaining high video quality and processing capability. [ABSTRACT FROM AUTHOR]

The conventional variable-size block motion compensation technique, even though superior to the fixed-size block motion-compensation technique, cannot fully utilize the motion information of a frame for its partitioning. This paper presents a quadtree structured region-wise motion-compensation technique that utilizes more effectively the motion content of a frame in terms of the shape, size, and location of the partitioned regions. The proposed technique is based on a new coding scheme of the quadtree structure, where a two-bit code is used. The partitioning of a given frame is carried out through the processes of merging and combining. The merging process partitions the frame into a number of regions by carrying out all possible 4-to-1, 3-to-1, and 2-to-1 merges along the quadtree hierarchy according to some specified criteria, while the combining process combines some of the partitioned regions that have the same motion vector into a single region. The motion vectors of the resulting partitioned regions are coded by a new coding scheme that uses the temporal correlation of the motion fields. Test results of applying the proposed method on a number of MPEG video sequences are included. These results indicate that the proposed method can provide a significantly improved rate-distortion performance [ABSTRACT FROM PUBLISHER]

Focuses on director Barry Levinson's presentation of Roy Hobbs, the central character in the film `The Natural.' Levinson's creation of a more sympathetic and more `perfect' Roy Hobbs; Development of Hobbs' sensitive and caring `child's friend' image; Use of camera placement and blocking to emphasize the relationship between Hobbs and the boy Bobby.

A novel half-pixel filter is proposed to extract one block with half-pixel precision motion vector in the DCT domain. The proposed filter reduces the computational complexity by integrating the interpolation and translation into a single step, while improves the video quality compared with the existing half-pixel filter. [ABSTRACT FROM AUTHOR]