This paper presented an object-based fast motion estimation (ME) algorithm for object-based texture coding in moving picture experts group four (MPEG-4), which takes full advantage of the shape information of video ob...This paper presented an object-based fast motion estimation (ME) algorithm for object-based texture coding in moving picture experts group four (MPEG-4), which takes full advantage of the shape information of video object. Compared with the full search (FS) algorithm, the proposed algorithm can significantly speed the ME process. The speed of ME using the proposed algorithm is faster than that using new three-step search (NTSS), four-step search (4SS), diamond search (DS), and block-based gradient descent search (BBGDS) algorithms with similar motion compensation (MC) errors. The proposed algorithm can be combined with other fast ME algorithm to make the ME process faster.展开更多
Motion estimation is an important part of the MPEG- 4 encoder, due to its significant impact on the bit rate and the output quality of the encoder sequence. Unfortunately this feature takes a significant part of the e...Motion estimation is an important part of the MPEG- 4 encoder, due to its significant impact on the bit rate and the output quality of the encoder sequence. Unfortunately this feature takes a significant part of the encoding time especially when the straightforward full search(FS) algorithm is used. In this paper, a new algorithm named diamond block based gradient descent search (DBBGDS) algorithm, which is significantly faster than FS and gives similar quality of the output sequence, is proposed. At the same time, some other algorithms, such as three step search (TSS), improved three step search (ITSS), new three step search (NTSS), four step search (4SS), cellular search (CS) , diamond search (DS) and block based gradient descent search (BBGDS), are adopted and compared with DBBGDS. As the experimental results show, DBBGDS has its own advantages. Although DS has been adopted by the MPEG- 4 VM, its output sequence quality is worse than that of the proposed algorithm while its complexity is similar to the proposed one. Compared with BBGDS, the proposed algorithm can achieve a better output quality.展开更多
Motion estimation plays an important role in the compression of video signals. This paper presents a median prediction search algorithm (MPS) for block motion estimation. The proposed method firstly uses the median of...Motion estimation plays an important role in the compression of video signals. This paper presents a median prediction search algorithm (MPS) for block motion estimation. The proposed method firstly uses the median of the motion vectors of the three adjacent blocks as the prediction motion vector, namely, the initial search point. By using a 3×3 movable search window, it then searches from the prediction point with a fixed search step size of one until it reaches the boundary of search area or its local minimum point lies in the center of search window. Based on the spatial characteristics of the center biased distance between a motion vector and the corresponding prediction vector and the temporal correlation of motion vectors, this method can significantly reduces search times. Simulation results show that the proposed MPS is better than the three step search algorithm and the four step search algorithm in terms of MSE with smaller computational requirement.展开更多
Generally,due to the limitation of the dimension of the array aperture,linear arrays cannot achieve two-dimensional(2D)direction of arrival(DOA)estimation.But the emergence of array motion provides a chance for that.I...Generally,due to the limitation of the dimension of the array aperture,linear arrays cannot achieve two-dimensional(2D)direction of arrival(DOA)estimation.But the emergence of array motion provides a chance for that.In this paper,a generalized motion scheme and a novel method of 2D DOA estimation are proposed by exploring the linear array motion.To be specific,the linear arrays are controlled to move along an arbitrary direction at a constant velocity and snap per fixed time delay.All the received signals are processed to synthesize the comprehensive observation vector for an extended 2D virtual aperture.Subsequently,since most of 2D DOA estimation methods are not universal to our proposed motion scheme and the reduced-dimensional(RD)method fails to handle the case of the coupled parameters,a decoupled reduced-complexity multiple signals classification(DRC MUSIC)algorithm is designed specifically.Simulation results demonstrate that:a)our proposed scheme can achieve underdetermined 2D DOA estimation just by the linear arrays;b)our designed DRC MUSIC algorithm has the good properties of high accuracy and low complexity;c)our proposed motion scheme with the DRC method has better universality in the motion direction.展开更多
This paper presents a new approach to the extraction of a moving object from video sequence. The method is based on morphological motion filter using connected operator and a proposed new filtering criterion. The morp...This paper presents a new approach to the extraction of a moving object from video sequence. The method is based on morphological motion filter using connected operator and a proposed new filtering criterion. The morphological motion filter aims to detect motion which is distinct from that of the background, and thereby locates independently moving physical objects in the scenes. Experiments show that the algorithm can extract object from moving backgrounds efficiently.展开更多
基金National High Technology Research and De-velopment Program of China (863 Program)(No.2003AA103810)
文摘This paper presented an object-based fast motion estimation (ME) algorithm for object-based texture coding in moving picture experts group four (MPEG-4), which takes full advantage of the shape information of video object. Compared with the full search (FS) algorithm, the proposed algorithm can significantly speed the ME process. The speed of ME using the proposed algorithm is faster than that using new three-step search (NTSS), four-step search (4SS), diamond search (DS), and block-based gradient descent search (BBGDS) algorithms with similar motion compensation (MC) errors. The proposed algorithm can be combined with other fast ME algorithm to make the ME process faster.
文摘Motion estimation is an important part of the MPEG- 4 encoder, due to its significant impact on the bit rate and the output quality of the encoder sequence. Unfortunately this feature takes a significant part of the encoding time especially when the straightforward full search(FS) algorithm is used. In this paper, a new algorithm named diamond block based gradient descent search (DBBGDS) algorithm, which is significantly faster than FS and gives similar quality of the output sequence, is proposed. At the same time, some other algorithms, such as three step search (TSS), improved three step search (ITSS), new three step search (NTSS), four step search (4SS), cellular search (CS) , diamond search (DS) and block based gradient descent search (BBGDS), are adopted and compared with DBBGDS. As the experimental results show, DBBGDS has its own advantages. Although DS has been adopted by the MPEG- 4 VM, its output sequence quality is worse than that of the proposed algorithm while its complexity is similar to the proposed one. Compared with BBGDS, the proposed algorithm can achieve a better output quality.
文摘Motion estimation plays an important role in the compression of video signals. This paper presents a median prediction search algorithm (MPS) for block motion estimation. The proposed method firstly uses the median of the motion vectors of the three adjacent blocks as the prediction motion vector, namely, the initial search point. By using a 3×3 movable search window, it then searches from the prediction point with a fixed search step size of one until it reaches the boundary of search area or its local minimum point lies in the center of search window. Based on the spatial characteristics of the center biased distance between a motion vector and the corresponding prediction vector and the temporal correlation of motion vectors, this method can significantly reduces search times. Simulation results show that the proposed MPS is better than the three step search algorithm and the four step search algorithm in terms of MSE with smaller computational requirement.
基金This work was supported in part by the Key R&D Program of Shandong Province,China(No.2020CXGC010109)in part by the Beijing Municipal Science and Technology Project(Z181100003218015).
文摘Generally,due to the limitation of the dimension of the array aperture,linear arrays cannot achieve two-dimensional(2D)direction of arrival(DOA)estimation.But the emergence of array motion provides a chance for that.In this paper,a generalized motion scheme and a novel method of 2D DOA estimation are proposed by exploring the linear array motion.To be specific,the linear arrays are controlled to move along an arbitrary direction at a constant velocity and snap per fixed time delay.All the received signals are processed to synthesize the comprehensive observation vector for an extended 2D virtual aperture.Subsequently,since most of 2D DOA estimation methods are not universal to our proposed motion scheme and the reduced-dimensional(RD)method fails to handle the case of the coupled parameters,a decoupled reduced-complexity multiple signals classification(DRC MUSIC)algorithm is designed specifically.Simulation results demonstrate that:a)our proposed scheme can achieve underdetermined 2D DOA estimation just by the linear arrays;b)our designed DRC MUSIC algorithm has the good properties of high accuracy and low complexity;c)our proposed motion scheme with the DRC method has better universality in the motion direction.
文摘This paper presents a new approach to the extraction of a moving object from video sequence. The method is based on morphological motion filter using connected operator and a proposed new filtering criterion. The morphological motion filter aims to detect motion which is distinct from that of the background, and thereby locates independently moving physical objects in the scenes. Experiments show that the algorithm can extract object from moving backgrounds efficiently.
