roundnessroundnessRoundnessRoundnessroundness（算子）

名称

roundnessroundnessRoundnessRoundnessroundness — 轮廓的形状系数。这里的圆度是圆周到中心的距离变化系数。和 Circularity 圆形度不同，Circularity 是和圆的相似程度。

签名

描述

算子 roundnessroundnessRoundnessRoundnessRoundnessroundness examines the distance between the contour and the center of the area. In particular the mean distance (DistanceDistanceDistanceDistancedistancedistance), the deviation from the mean distance (SigmaSigmaSigmaSigmasigmasigma) and two shape features derived therefrom are determined. RoundnessRoundnessRoundnessRoundnessroundnessroundness is the relation between mean value and standard deviation, and SidesSidesSidesSidessidessides indicates the number of polygon pieces if a regular polygon is concerned.

In the documentation of this chapter (Regions / Features), you can find an image illustrating regions which vary in their mean distance, distance deviation, roundness and number of polygon pieces.

The contour for calculating the features is determined depending on the global neighborhood (see set_systemset_systemSetSystemSetSystemSetSystemset_system).

Calculation:

If p is the center of the area, the pixels and F the area of the contour.

If more than one region is passed the results are stored in tuples, the index of a value in the tuple corresponding to the index of a region in the input.

In case of empty region all parameters have the value 0.0 if no other behavior was set (see set_systemset_systemSetSystemSetSystemSetSystemset_system).

执行信息

• 多线程类型：可重入（与非独占算子并行运行）。
• 多线程作用域：全局（可从任何线程调用）。
• 在元组级别上自动并行化。

参数

复杂度

If F is the area of a region the mean runtime complexity is O(sqrt(F)).

结果

算子 roundnessroundnessRoundnessRoundnessRoundnessroundness 在输入不为空时返回值 2 ( H_MSG_TRUE )。当输入为空（无可用输入区域）时，可设置行为通过算子 set_system('no_object_result',<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)set_system("no_object_result",<Result>), the behavior in case of empty region is set via set_system('empty_region_result',<Result>)set_system("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)set_system("empty_region_result",<Result>)。如有必要，则抛出异常。

可能的前趋

thresholdthresholdThresholdThresholdThresholdthreshold, regiongrowingregiongrowingRegiongrowingRegiongrowingRegiongrowingregiongrowing, connectionconnectionConnectionConnectionConnectionconnection

替代

compactnesscompactnessCompactnessCompactnessCompactnesscompactness

另见

contlengthcontlengthContlengthContlengthContlengthcontlength

参考文献

R. Haralick, L. Shapiro “Computer and Robot Vision” Addison-Wesley, 1992, pp. 61

模块

基础

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