In this paper,we propose a novel adjustable multiple cross-hexagonal search(AMCHS) algorithm for fast block motion estimation. It employs adjustable multiple cross search patterns(AMCSP) in the first step and then use...In this paper,we propose a novel adjustable multiple cross-hexagonal search(AMCHS) algorithm for fast block motion estimation. It employs adjustable multiple cross search patterns(AMCSP) in the first step and then uses half-way-skip and half-way-stop technique to determine whether to employ two hexagonal search patterns(HSPs) subsequently. The AMCSP can be used to find small motion vectors efficiently while the HSPs can be used to find large ones accurately to ensure prediction quality. Simulation results showed that our proposed AMCHS achieves faster search speed,and provides better distortion performance than other popular fast search algorithms,such as CDS and CDHS.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
In this paper, we proposed a novel Two-layer Motion Estimation(TME) which searches motion vectors on two layers with partial distortion measures in order to reduce the overwhelming computational complexity of Motion E...In this paper, we proposed a novel Two-layer Motion Estimation(TME) which searches motion vectors on two layers with partial distortion measures in order to reduce the overwhelming computational complexity of Motion Estimation(ME) in video coding. A layer is an image which is derived from the reference frame such that the sum of a block of pixels in the reference frame determines the point of a layer. It has been noticed on different video sequences that many motion vectors on the layers are the same as those searched on the reference frame. The proposed TME performs a coarse search on the first layer to identify the small region in which the best candidate block is likely to be positioned and then perform local refined search on the next layer to pick the best candidate block in the located small area. The key feature of TME is its flexibility of mixing with any fast search algorithm. Experimental results on a wide variety of video sequences show that the proposed algorithm has achieved both fast speed and good motion prediction quality when compared to well known as well as the state-of-the-art fast block matching algorithms.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
提出了一种基于块特性与自适应搜索窗口的运动估计算法(Motion estimation algorithm based on blockcharacteristic and adaptive search window,MBC-ASW),该算法在充分利用视频图像的时间、空间相关性的同时,根据运动向量的统计特性,...提出了一种基于块特性与自适应搜索窗口的运动估计算法(Motion estimation algorithm based on blockcharacteristic and adaptive search window,MBC-ASW),该算法在充分利用视频图像的时间、空间相关性的同时,根据运动向量的统计特性,分别在帧层和块层进行自适应搜索窗口的粗调与微调,并且针对不同的块进行相应的编码处理。在PC上利用C语言实验验证了该算法的可行性,评估了其性能,并与经典的全搜索算法(Fullsearch motion estimation,FS)、三步搜索算法(Three step search,TSS)、新三步搜索算法(New three stepsearch,NTSS)和钻石搜索算法(Diamond search,DS)进行了详细的比较,该算法在性能和效率上均有较大程度的提高,对不同的序列具有较强的自适应性。展开更多
文摘In this paper,we propose a novel adjustable multiple cross-hexagonal search(AMCHS) algorithm for fast block motion estimation. It employs adjustable multiple cross search patterns(AMCSP) in the first step and then uses half-way-skip and half-way-stop technique to determine whether to employ two hexagonal search patterns(HSPs) subsequently. The AMCSP can be used to find small motion vectors efficiently while the HSPs can be used to find large ones accurately to ensure prediction quality. Simulation results showed that our proposed AMCHS achieves faster search speed,and provides better distortion performance than other popular fast search algorithms,such as CDS and CDHS.
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In this paper, we proposed a novel Two-layer Motion Estimation(TME) which searches motion vectors on two layers with partial distortion measures in order to reduce the overwhelming computational complexity of Motion Estimation(ME) in video coding. A layer is an image which is derived from the reference frame such that the sum of a block of pixels in the reference frame determines the point of a layer. It has been noticed on different video sequences that many motion vectors on the layers are the same as those searched on the reference frame. The proposed TME performs a coarse search on the first layer to identify the small region in which the best candidate block is likely to be positioned and then perform local refined search on the next layer to pick the best candidate block in the located small area. The key feature of TME is its flexibility of mixing with any fast search algorithm. Experimental results on a wide variety of video sequences show that the proposed algorithm has achieved both fast speed and good motion prediction quality when compared to well known as well as the state-of-the-art fast block matching algorithms.
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.
文摘提出了一种基于块特性与自适应搜索窗口的运动估计算法(Motion estimation algorithm based on blockcharacteristic and adaptive search window,MBC-ASW),该算法在充分利用视频图像的时间、空间相关性的同时,根据运动向量的统计特性,分别在帧层和块层进行自适应搜索窗口的粗调与微调,并且针对不同的块进行相应的编码处理。在PC上利用C语言实验验证了该算法的可行性,评估了其性能,并与经典的全搜索算法(Fullsearch motion estimation,FS)、三步搜索算法(Three step search,TSS)、新三步搜索算法(New three stepsearch,NTSS)和钻石搜索算法(Diamond search,DS)进行了详细的比较,该算法在性能和效率上均有较大程度的提高,对不同的序列具有较强的自适应性。
