A novel four-step search algorithm for fast block motion estimation
01 Jun 1996-IEEE Transactions on Circuits and Systems for Video Technology (IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY)-Vol. 6, Iss: 3, pp 313-317
TL;DR: Simulation results show that the proposed 4SS performs better than the well-known three- step search and has similar performance to the new three-step search (N3SS) in terms of motion compensation errors.
Abstract: Based on the real world image sequence's characteristic of center-biased motion vector distribution, a new four-step search (4SS) algorithm with center-biased checking point pattern for fast block motion estimation is proposed in this paper. A halfway-stop technique is employed in the new algorithm with searching steps of 2 to 4 and the total number of checking points is varied from 17 to 27. Simulation results show that the proposed 4SS performs better than the well-known three-step search and has similar performance to the new three-step search (N3SS) in terms of motion compensation errors. In addition, the 4SS also reduces the worst-case computational requirement from 33 to 27 search points and the average computational requirement from 21 to 19 search points, as compared with N3SS.
Citations
More filters
TL;DR: Experimental results show that the proposed diamond search (DS) algorithm is better than the four-step search (4SS) and block-based gradient descent search (BBGDS), in terms of mean-square error performance and required number of search points.
Abstract: Based on the study of motion vector distribution from several commonly used test image sequences, a new diamond search (DS) algorithm for fast block-matching motion estimation (BMME) is proposed in this paper. Simulation results demonstrate that the proposed DS algorithm greatly outperforms the well-known three-step search (TSS) algorithm. Compared with the new three-step search (NTSS) algorithm, the DS algorithm achieves close performance but requires less computation by up to 22% on average. Experimental results also show that the DS algorithm is better than the four-step search (4SS) and block-based gradient descent search (BBGDS), in terms of mean-square error performance and required number of search points.
1,949 citations
Cites result from "A novel four-step search algorithm ..."
...search(LOGS) [2], three-step search(TSS) [3], conjugate direction search(CDS) [4],cross search(CS) [5],new three-step search (NTSS) [6], four-step search(4SS) [7],block-based gradient descent search (BBGDS) [8], etc....
[...]
...Using a moderate search pattern with fixed size of 5 5, 4SS [7] obtains similar performance compared to that of NTSS....
[...]
TL;DR: Analysis shows that a speed improvement rate of the hexagon-based search (HEXBS) algorithm over the diamond search (DS) algorithm can be over 80% for locating some motion vectors in certain scenarios.
Abstract: In block motion estimation, a search pattern with a different shape or size has a very important impact on search speed and distortion performance. A square-shaped search pattern is adopted in many popular fast algorithms. Recently, a diamond-shaped search pattern was introduced in fast block motion estimation and has exhibited a faster search speed. Based on an in-depth examination of the influence of the search pattern on speed performance, we propose a novel algorithm using a hexagon-based search pattern to achieve further improvement. The hexagon-based search pattern is investigated in comparison with diamond search pattern and demonstrates significant speedup gain over the diamond-based search. Analysis shows that a speed improvement rate of the hexagon-based search (HEXBS) algorithm over the diamond search (DS) algorithm can be over 80% for locating some motion vectors in certain scenarios. In short, the proposed HEXBS algorithm can find the same motion vector with fewer search points than the DS algorithm. Generally speaking, the larger the motion vector, the more search points the. HEXBS algorithm can save, which is further justified by experimental results.
860 citations
TL;DR: A novel unrestricted center-biased diamond search (UCBDS) algorithm is proposed which is more efficient, effective, and robust than the previous techniques and consistently faster than the other suboptimal block-matching techniques.
Abstract: The widespread use of block-based interframe motion estimation for video sequence compression in both MPEG and H.263 standards is due to its effectiveness and simplicity of implementation. Nevertheless, the high computational complexity of the full-search algorithm has motivated a host of suboptimal but faster search strategies. A popular example is the three-step search (TSS) algorithm. However, its uniformly spaced search pattern is not well matched to most real-world video sequences in which the motion vector distribution is nonuniformly biased toward the zero vector. Such an observation inspired the new three-step search (NTSS) which has a center-biased search pattern and supports a halfway-stop technique. It is faster on average, and gives better motion estimation as compared to the well-known TSS. Later, the four-step search (4SS) algorithm was introduced to reduce the average case from 21 to 19 search points, while maintaining a performance similar to NTSS in terms of motion compensation errors. We propose a novel unrestricted center-biased diamond search (UCBDS) algorithm which is more efficient, effective, and robust than the previous techniques. It has a best case scenario of only 13 search points and an average of 15.5 block matches. This makes UCBDS consistently faster than the other suboptimal block-matching techniques. This paper also compares the above methods in which both the processing speed and the accuracy of motion compensation are tested over a wide range of test video sequences.
680 citations
Cites background or methods from "A novel four-step search algorithm ..."
...According to [10], 4SS gives a speedup of six block matches for the worst case, and an average of two block matches less than the NTSS....
[...]
...Recently, a new four-step search (4SS) algorithm [10] was proposed to speed up both the worst case and average-case computational requirements of NTSS....
[...]
...Nevertheless, simulation results in [10] show that the total number of candidate search points in 4SS actually ranges from the best case of 17 to the worst case of 27 points....
[...]
TL;DR: The search speed of the proposed ARPS-ZMP is about two to three times faster than that of the diamond search (DS), and the method even achieves higher peak signal-to-noise ratio (PSNR) particularly for those video sequences containing large and/or complex motion contents.
Abstract: We propose a novel and simple fast block-matching algorithm (BMA), called adaptive rood pattern search (ARPS), which consists of two sequential search stages: (1) initial search and (2) refined local search. For each macroblock (MB), the initial search is performed only once at the beginning in order to find a good starting point for the follow-up refined local search. By doing so, unnecessary intermediate search and the risk of being trapped into local minimum matching error points could be greatly reduced in long search case. For the initial search stage, an adaptive rood pattern (ARP) is proposed, and the ARP's size is dynamically determined for each MB, based on the available motion vectors (MVs) of the neighboring MBs. In the refined local search stage, a unit-size rood pattern (URP) is exploited repeatedly, and unrestrictedly, until the final MV is found. To further speed up the search, zero-motion prejudgment (ZMP) is incorporated in our method, which is particularly beneficial to those video sequences containing small motion contents. Extensive experiments conducted based on the MPEG-4 Verification Model (VM) encoding platform show that the search speed of our proposed ARPS-ZMP is about two to three times faster than that of the diamond search (DS), and our method even achieves higher peak signal-to-noise ratio (PSNR) particularly for those video sequences containing large and/or complex motion contents.
605 citations
Cites background from "A novel four-step search algorithm ..."
...[2], four-step search(4SS) [3],block-based gradient descent search(BBGDS) [4] and the latest diamond search(DS) [5]....
[...]
TL;DR: The proposed cross-diamond search (CDS) algorithm employs the halfway-stop technique and finds small motion vectors with fewer search points than the DS algorithm while maintaining similar or even better search quality.
Abstract: In block motion estimation, search patterns with different shapes or sizes and the center-biased characteristics of motion-vector distribution have a large impact on the searching speed and quality of performance. We propose a novel algorithm using a cross-search pattern as the initial step and large/small diamond search (DS) patterns as the subsequent steps for fast block motion estimation. The initial cross-search pattern is designed to fit the cross-center-biased motion vector distribution characteristics of the real-world sequences by evaluating the nine relatively higher probable candidates located horizontally and vertically at the center of the search grid. The proposed cross-diamond search (CDS) algorithm employs the halfway-stop technique and finds small motion vectors with fewer search points than the DS algorithm while maintaining similar or even better search quality. The improvement of CDS over DS can be up to a 40% gain on speedup. Experimental results show that the CDS is much more robust, and provides faster searching speed and smaller distortions than other popular fast block-matching algorithms.
392 citations
Cites methods from "A novel four-step search algorithm ..."
...In the last two decades, many fast block-matching algorithms (BMA) were proposed for alleviating the heavy computations consumed by the brute-force full-search algorithm (FS), such as the three-step search (3SS) [6], the new three-step search (N3SS) [7], the four-step search (4SS) [ 8 ], the block-based gradient descent search (BBGDS) [9], and the diamond search (DS) [10], [11] algorithms, etc....
[...]
References
More filters
TL;DR: The motion compensation is applied for analysis and design of a hybrid coding scheme and the results show a factor of two gain at low bit rates.
Abstract: A new technique for estimating interframe displacement of small blocks with minimum mean square error is presented. An efficient algorithm for searching the direction of displacement has been described. The results of applying the technique to two sets of images are presented which show 8-10 dB improvement in interframe variance reduction due to motion compensation. The motion compensation is applied for analysis and design of a hybrid coding scheme and the results show a factor of two gain at low bit rates.
1,883 citations
Additional excerpts
...The authors are with the CityU Image Processing Lab, Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong....
[...]
TL;DR: Simulation results show that, as compared to TSS, NTSS is much more robust, produces smaller motion compensation errors, and has a very compatible computational complexity.
Abstract: The three-step search (TSS) algorithm has been widely used as the motion estimation technique in some low bit-rate video compression applications, owing to its simplicity and effectiveness. However, TSS uses a uniformly allocated checking point pattern in its first step, which becomes inefficient for the estimation of small motions. A new three-step search (NTSS) algorithm is proposed in the paper. The features of NTSS are that it employs a center-biased checking point pattern in the first step, which is derived by making the search adaptive to the motion vector distribution, and a halfway-stop technique to reduce the computation cost. Simulation results show that, as compared to TSS, NTSS is much more robust, produces smaller motion compensation errors, and has a very compatible computational complexity. >
1,689 citations
01 Jan 1981
1,676 citations
"A novel four-step search algorithm ..." refers methods in this paper
...The speed-up ratio of the BMAs is compared by the average search points required for a motion vector estimation....
[...]
...Among the proposed BMA’s, the 3SS became the most popular one and it is also recommended by RM8 of H.261 and SM3 of MPEG owing to its simplicity and effectiveness....
[...]
...As a result many fast BMA’s [5-12] had been developed to alleviate the heavy computations of FS....
[...]
...Using the motion vector found by FS as the true motion vector, Table 4 shows the probability of finding the true motion vector using different fast BMAs....
[...]
...For examples the three-step search (3SS) [5], the 2D-logarithm search (LOGS) [6], the conjugate directional search [7,8], the cross-search algorithm [9], and the dynamic search-window adjustment algorithm [10], etc....
[...]
TL;DR: Two algorithms for block motion estimation that produce performance similar to that of exhaustive search but with computation reduced by a factor of 8 or 16 are presented.
Abstract: Two algorithms for block motion estimation that produce performance similar to that of exhaustive search but with computation reduced by a factor of 8 or 16 are presented. The algorithms are based on motion-field and pixel subsampling. A subsampled motion field is first determined by estimating the motion vectors for a fraction of the blocks. The motion vectors for these blocks are determined by using only a fraction of the pixels at any searched location and by alternating the pixel subsampling patterns with the searched locations. The subsampled motion field is then interpolated so that a motion vector is determined for each block of pixels. The algorithms are more robust than previously proposed fast algorithms and both can easily be combined with a hierarchical search strategy. One of the algorithms is fully compatible with MPEG-I. >
658 citations
TL;DR: A computationally simpler and effective method is proposed for estimating motion in a video sequence based on conjugate directions and another simpler technique called the one-at-a-time search, adopted as the basis for further research.
Abstract: A computationally simpler and effective method is proposed for estimating motion in a video sequence. The paper outlines a search technique based on conjugate directions [3], [4] and another simpler technique called the one-at-a-time search [3]. Based on the comparison of the two methods, the latter technique is adopted as the basis for further research. The adopted technique is compared with brute force search, existing 2-D logarithmic search [1], and a modified version of it [2], for motion compensated prediction [5].
602 citations