Abstract One of the important problems of automatic threshold image segmentation by brightness are questions of the number of brightness classes and, as a consequence, the required number of thresholds. The solution to the problem of estimating the number of classes in an image is often based on representing its distribution as a mixture of distributions of brightness classes. It is known that this problem (splitting a mixture) has a solution only for some types of distributions, and is difficult to apply when the distributions of brightness classes are unknown. This paper presents a nonparametric method for determining the number of classes based on rank histograms and using the property of the local spatial grouping of elements of each brightness class in the image. Comparison of the proposed method to different criteria for assessing the number of classes in images showed it to be effective.

中文翻译：

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图像分割中估计类数的非参数方法

摘要 亮度自动阈值图像分割的重要问题之一是亮度等级的数量问题，因此，所需的阈值数量。估计图像中类别数量问题的解决方案通常基于将其分布表示为亮度类别分布的混合。众所周知，这个问题（分裂混合）只对某些类型的分布有解，当亮度等级的分布未知时很难应用。本文提出了一种基于秩直方图并利用图像中每个亮度类元素的局部空间分组特性来确定类数的非参数方法。