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基于直方图距离的广义VS集中位数字符串:图像域中的算法和分类结果

Generalized vs Set Median String for Histogram Based Distances: Algorithms and Classification Results in the Image Domain
课程网址: http://videolectures.net/gbr07_jolion_gsms/  
主讲教师: Jean-Michel Jolion
开课单位: 里昂国立应用科学学院
开课时间: 2007-07-12
课程语种: 英语
中文简介:
我们比较了一组字符串对三种不同的基于直方图的距离的不同统计特征。给定一个距离,一组字符串的特征可以是其广义中值,即所有可能字符串集合上的字符串—,该字符串最小化到集合中每个字符串的距离之和,或其集合中值,即最小化到集合中每个其他字符串的距离之和的集合字符串。对于前两个基于柱状图的距离,我们证明了广义中值字符串可以有效地计算;对于第三个基于单个替换成本的偏倚柱状图,我们推测这是一个NP难题,并且我们引入了两种不同的启发式近似算法。我们在实验上比较了三种基于柱状图的距离的相关性,以及字符串集的不同统计特征,以便对由字符串表示的图像进行分类。
课程简介: We compare different statistical characterizations of a set of strings, for three different histogram-based distances. Given a distance, a set of strings may be characterized by its generalized median, i.e., the string —over the set of all possible strings— that minimizes the sum of distances to every string of the set, or by its set median, i.e., the string of the set that minimizes the sum of distances to every other string of the set. For the first two histogram-based distances, we show that the generalized median string can be computed efficiently; for the third one, which biased histograms with individual substitution costs, we conjecture that this is a NP-hard problem, and we introduce two different heuristic algorithms for approximating it. We experimentally compare the relevance of the three histogram-based distances, and the different statistical characterizations of sets of strings, for classifying images that are represented by strings.
关 键 词: 统计特征; 人替代成本; 启发式算法
课程来源: 视频讲座网
最后编审: 2019-11-30:lxf
阅读次数: 46