A fast stereo matching algorithm suitable for embedded real-time systems
A fast stereo matching algorithm suitable for embedded real-time systems
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DOI：
10.1016/j.cviu.2010.03.012
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发表时间：
2010-11-01
影响因子：
4.5
通讯作者：
Vincze, Markus
中科院分区：
文献类型：
--
作者：
Humenberger, Martin;Zinner, Christian;Vincze, Markus
本文针对嵌入式系统的快速立体匹配问题进行了研究。有限的资源，例如内存和处理能力，以及最重要的机器人应用嵌入式系统的实时能力，不允许使用最复杂的立体匹配方法。分析了不同匹配方法的优缺点，并在基于人口普查的立体匹配算法中找到了合适的解决方案。该算法的新颖之处在于在软件中对众所周知的嵌入式实时系统的Census变换进行了显式的适应和优化。与经典的普查变换相比，最重要的变化是使用了稀疏的普查掩码，在匹配质量几乎不变的情况下将处理时间减半。这是因为在相同的处理工作量下，大的稀疏的Census掩码比小的密集掩码表现得更好。不同掩膜尺寸的实验结果证明了这一假设。本工作的另一个贡献是提出了一个完整的立体匹配系统及其基于相关性的核心算法，对结果进行了详细的分析和评估，并在不同的嵌入式和PC平台上优化了高速实现。与最先进的实时方法相比，该算法可以很好地处理难以进行立体匹配的区域，例如低纹理区域。它可以成功地消除误报，提供可靠的3D数据。该系统鲁棒性好，参数化容易，灵活性高。它还在几个系统上实现高性能，包括资源有限的系统，而不会失去良好的立体声匹配质量。对该算法进行了详细的性能分析，并在各种商用货架（COTS）平台（如PC、DSP和GPU）上进行了优化参考实现，在640 x 480图像和50差的情况下达到了高达75 fps的帧率。匹配质量和处理时间与Middlebury立体声评价网站上的其他算法进行了比较，达到了中等质量和顶级性能排名。通过使用几个Middlebury数据集和真实场景，将结果与非常快速且众所周知的绝对差和算法进行比较，从而完成额外的评估。(c) 2010爱思唯尔公司版权所有。
In this paper, the challenge of fast stereo matching for embedded systems is tackled. Limited resources, e.g. memory and processing power, and most importantly real-time capability on embedded systems for robotic applications, do not permit the use of most sophisticated stereo matching approaches. The strengths and weaknesses of different matching approaches have been analyzed and a well-suited solution has been found in a Census-based stereo matching algorithm. The novelty of the algorithm used is the explicit adaption and optimization of the well-known Census transform in respect to embedded real-time systems in software. The most important change in comparison with the classic Census transform is the usage of a sparse Census mask which halves the processing time with nearly unchanged matching quality. This is due the fact that large sparse Census masks perform better than small dense masks with the same processing effort. The evidence of this assumption is given by the results of experiments with different mask sizes. Another contribution of this work is the presentation of a complete stereo matching system with its correlation-based core algorithm, the detailed analysis and evaluation of the results, and the optimized high speed realization on different embedded and PC platforms. The algorithm handles difficult areas for stereo matching, such as areas with low texture, very well in comparison to state-of-the-art real-time methods. It can successfully eliminate false positives to provide reliable 3D data. The system is robust, easy to parameterize and offers high flexibility. It also achieves high performance on several, including resource-limited, systems without losing the good quality of stereo matching. A detailed performance analysis of the algorithm is given for optimized reference implementations on various commercial of the shelf (COTS) platforms, e.g. a PC, a DSP and a GPU, reaching a frame rate of up to 75 fps for 640 x 480 images and 50 disparities. The matching quality and processing time is compared to other algorithms on the Middlebury stereo evaluation website reaching a middle quality and top performance rank. Additional evaluation is done by comparing the results with a very fast and well-known sum of absolute differences algorithm using several Middlebury datasets and real-world scenarios. (c) 2010 Elsevier Inc. All rights reserved.