Moving object detection (MOD) has gained significant attention for its application in advanced video surveillance tasks. Region-of-Interest (ROI) detection algorithms are essential prerequisites for various applicatio...
详细信息
Moving object detection (MOD) has gained significant attention for its application in advanced video surveillance tasks. Region-of-Interest (ROI) detection algorithms are essential prerequisites for various applications, ranging from video surveillance to adaptive videocoding. The simplicity and efficiency of MOD methods are critical when targeting energy-constrained systems, such as Wireless Multimedia Sensor Networks (WMSN). The challenge is always to reduce computational costs while preserving high detection accuracy. In this article, we present EVBS-CAT, an Enhanced video Background Subtraction with a Controlled Adaptive Threshold selection method for low-cost surveillance systems. The proposed moving object detection method utilizes background subtraction (BS) with morphological operations and adaptive thresholding. We evaluate the algorithm using the Change Detection 2012 dataset. Through a computational complexity analysis of each step, we demonstrate the efficiency of the proposed MOD technique for embedded WMSN. The algorithm yields promising results compared to state-of-the-art MOD techniques in the context of embedded wireless surveillance.
In recent years, intelligent video surveillance attempts to provide content analysis tools to understand and predict the actions via video sensor networks (VSN) for automated wide-area surveillance. In this emerging n...
详细信息
In recent years, intelligent video surveillance attempts to provide content analysis tools to understand and predict the actions via video sensor networks (VSN) for automated wide-area surveillance. In this emerging network, visual object data is transmitted through different devices to adapt to the needs of the specific content analysis task. Therefore, they raise a new challenge for video delivery: how to efficiently transmit visual object data to various devices such as storage device, content analysis server, and remote client server through the network. object-basedvideo encoder can be used to reduce transmission bandwidth with minor quality loss. However, the involved motion-compensated technique often leads to high computational complexity and consequently increases the cost of VSN. In this paper, contextual redundancy associated with background and foreground objects in a scene is explored. A scene analysis method is proposed to classify macroblocks (MBs) by type of contextual redundancy. The motion search is only performed on the specific type of context of MB which really involves salient motion. To facilitate the encoding by context of MB, an improved object-basedcoding architecture, namely dual-closed-loop encoder, is derived. It encodes the classified context of MB in an operational rate-distortion-optimized sense. The experimental results show that the proposed coding framework can achieve higher coding efficiency than MPEG-4 coding and related object-basedcoding approaches, while significantly reducing coding complexity.
Bandwidth-constrained real-time conversational video communications (such as mobile teleconferencing) require video codecs with good rate-distortion characteristics at low bit-rates and modest computational complexity...
详细信息
Bandwidth-constrained real-time conversational video communications (such as mobile teleconferencing) require video codecs with good rate-distortion characteristics at low bit-rates and modest computational complexity. While target-specific object-based and model-basedcoding methods have been proposed for low bit-rate conversational videocoding, difficulties in generalization and high computational complexity hinder their practical utilization. In this paper, we propose a low bit-rate coding method for typical conversational video by combining two-dimensional model-basedcoding of face regions and object-basedcoding of non-face head-shoulder regions, achieving high-quality face reconstruction and low overall bit-rate with real-time encoding capability. Experiments on typical conversational test sequences confirm that, compared to other conversational video codecs, our model-and-object-basedcoding method offers superior rate-distortion performance at low bit-rates. (C) 2015 Elsevier B.V. All rights reserved.
This paper presents a novel video encoding method for cooperative educational dissemination systems. Taking into consideration the inherent characteristics of stereo cameras framework in Our educational videos and the...
详细信息
ISBN:
(纸本)9783540899846
This paper presents a novel video encoding method for cooperative educational dissemination systems. Taking into consideration the inherent characteristics of stereo cameras framework in Our educational videos and the ability of determining objects in different depths in a scene, we have proposed a novel object-basedvideo encodingbased on "sprite coding" that supports the MPEG-4 Version 1 Main profile in order to transfer distance learning videos across narrow-band transmission links such as the Internet. This paper proposes a multi-layer videoobject layer generation scheme with fore.-round moving object extraction and background sprite generation using stereo camera property. The foreground object is coded as a videoobject plane of its related layer, while the background sprite is coded using sprite coding in MPEG-4. We call this coding scheme "sprite mode". Experiments are conducted on videoobject plane generation and videocoding using MPEG-4. We have compared the performance of our sprite mode with MPEG-4 normal mode and have shown that the coding efficiency of the sprite mode is higher than that of the normal mode at the same objective image quality when the foreground ratio is around 30%.
Geometric distortion measurement and the associated metrics involved are integral to the Rate Distortion (RD) shape coding framework, with importantly the efficacy of the metrics being strongly influenced by the under...
详细信息
Geometric distortion measurement and the associated metrics involved are integral to the Rate Distortion (RD) shape coding framework, with importantly the efficacy of the metrics being strongly influenced by the underlying measurement strategy. This has been the catalyst for many different techniques with this article presenting a comprehensive review of geometric distortion measurement, the diverse metrics applied, and their impact on shape coding. The respective performance of these measuring strategies is analyzed from both a RD and complexity perspective, with a recent distortion measurement technique based on arc-length-parameterization being comparatively evaluated. Some contemporary research challenges are also investigated, including schemes to effectively quantify shape deformation.
This paper proposes an improved rate control algorithm for jointly encoding multiple arbitrarily shaped videoobjects in the context of low-delay MPEG-4 compliant videocoding. The algorithm provides adequate mechanis...
详细信息
This paper proposes an improved rate control algorithm for jointly encoding multiple arbitrarily shaped videoobjects in the context of low-delay MPEG-4 compliant videocoding. The algorithm provides adequate mechanisms for dealing with deviations between the ideal and the actual behavior of video scene encoders, notably: 1) compensation mechanisms (e. g., rate control decisions) that are able to track these deviations and compensate them to allow a stable and efficient operation of the encoder, and 2) adaptation mechanisms (e. g., estimation of model parameters) that are able to instantaneously represent the actual behavior of the encoder and its rate controller. The proposed solution efficiently allocates the available resources, i.e., target bit rate and bitstream buffer space, aiming at maximizing the average scene quality and minimizing quality fluctuations along time and among the various videoobjects. The results show that this solution outperforms the usual reference solutions, notably those specified in the rate control informative annex of the MPEG-4 visual standard.
Work is currently underway to develop a new multi-view videocoding (MVC) standard, based on the recent H.264/AVC standard. Recent work has shown, however, that object-based video coding can provide higher performance...
详细信息
ISBN:
(纸本)9781424407217
Work is currently underway to develop a new multi-view videocoding (MVC) standard, based on the recent H.264/AVC standard. Recent work has shown, however, that object-based video coding can provide higher performance than H.264, especially at low bit rates and in sequences containing rotating camera motion and moving objects in the foreground. In this paper, we propose an object-based extension to MVC, in which sequences are segmented into foreground and background objects, with each object coded using H.264/AVC for single-view sequences and MVC for multi-view sequences. Experimental results show that the object-based approach significantly outperforms the basic MVC at low bit rates.
In this paper, a new lifting-based shape-direction-adaptive discrete wavelet transform (SDA-DWT) which can be used for arbitrarily shaped segments is proposed. The SDA-DWT contains three major techniques;the lifting-b...
详细信息
In this paper, a new lifting-based shape-direction-adaptive discrete wavelet transform (SDA-DWT) which can be used for arbitrarily shaped segments is proposed. The SDA-DWT contains three major techniques;the lifting-based DWT, the adaptive directional technique, and the concept of object-based compression in MPEG-4. With SDA-DWT, the number of transformed coefficients is equal to the number of pixels in the arbitrarily shaped segment image, and the spatial correlation across sub-bands is well preserved. SDA-DWT also can locally adapt its filtering directions according to the texture orientations to improve eneryg compaction for images containing non-horizontal or non-vertical edge textures. SDA-DWT can be applied to any application that is wavelet based and the lifing technique provides much flexibility for hardware implementation. Experimental results show that, for still object images with rich orientation textures. SDA-DWT outperforms SA-DWT up to 5.88 dB in PSNR under 2.15-bpp (bit/onject pixel) condition, and reduces the bit-budget up tio 14.0%.
object-based video coding, as standardized in MPEG-4 Part 2, can result in superior performance in comparison to common hybrid motion-compensated DCT-based approaches. We consider sprite coding which increases signifi...
详细信息
ISBN:
(纸本)9789537044060
object-based video coding, as standardized in MPEG-4 Part 2, can result in superior performance in comparison to common hybrid motion-compensated DCT-based approaches. We consider sprite coding which increases significantly the objective as well as the subjective quality of the coded video. The main challenge of this approach is the pre-segmentation of the video and the video content itself To apply sprite coding, the input video has to be firstly segmented into foreground and background objects. We evaluate automatic object segmentation methods based on global motion estimation and background sprite generation. These algorithms are evaluated using the standardized MPEG-4 Visual Main Profile (sprite coding).
This paper proposes new buffer and videoobject distortion feedback compensation mechanisms for efficiently dealing with deviations between the ideal and the actual behavior of video scene encoders when jointly encodi...
详细信息
ISBN:
(纸本)9781424414369
This paper proposes new buffer and videoobject distortion feedback compensation mechanisms for efficiently dealing with deviations between the ideal and the actual behavior of video scene encoders when jointly encoding multiple arbitrarily shaped videoobjects in the context of compliant low-delay object-based MPEG-4 videocoding. The proposed solution computes target buffer occupancies for each encoding time instant based on the amount and complexity of the video data to encode, and the bit allocation for each encoding time instant is feedback adjusted according to deviations relatively to this ideal behavior. Additionally, each videoobject bit allocation is also feedback adjusted based on the relative distortion of the various videoobjects in the scene. The proposed solution outperforms the non-normative MPEG-4 reference rate control algorithm for a wide range of bit rates and spatio-temporal resolutions, for typical test sequences.
暂无评论