moments_region_2ndmoments_region_2ndMomentsRegion2ndMomentsRegion2ndmoments_region_2nd (算子名称)

名称

moments_region_2ndmoments_region_2ndMomentsRegion2ndMomentsRegion2ndmoments_region_2nd — Calculate the geometric moments of regions.

参数签名

描述

moments_region_2ndmoments_region_2ndMomentsRegion2ndMomentsRegion2ndMomentsRegion2ndmoments_region_2nd calculates the geometric moments M11M11M11M11m11m11, M20M20M20M20m20m20 and M02M02M02M02m02m02 of the input regions in 区域区域区域区域区域区域. Furthermore the major and minor axis of the input regions are calculated and returned in IaIaIaIaiaia and IbIbIbIbibib.

The covariance matrix is given by:

The row-dependent moment of 2nd order is returned in M20M20M20M20m20m20 and the column-dependent moment of 2nd order is returned in M02M02M02M02m02m02. The moment M11M11M11M11m11m11 represents the covariance between the row and column coordinates of the region points.

Calculation:

and are the coordinates of the center of gravity of a region R. Then the moments are defined by:

wherein r and c run over all pixels of the region R.

Furthermore the length of the major and minor axes are defined by:

wherein is defined by:

The equation for the major and minor axes can be derived from the definition of the moments by diagonalizing the covariance matrix and reforming the resulting formula.

If more than one region is passed, the results are returned in tuples. The index of a tuple element corresponds to the index of the respective input region.

If an empty region is passed, 0.0 is returned for all parameters, if no other behavior was set (see set_systemset_systemSetSystemSetSystemSetSystemset_system).

运行信息

• 多线程类型:可重入(与非独占操作符并行运行)。
• 多线程作用域:全局(可以从任何线程调用)。
• 在元组级别自动并行化。

参数表

Complexity

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

结果

该算子 moments_region_2ndmoments_region_2ndMomentsRegion2ndMomentsRegion2ndMomentsRegion2ndmoments_region_2nd 返回值 2 ( H_MSG_TRUE) if the input is not empty. The behavior in case of empty input (no input regions available) is set via 该算子 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 (region is the empty set) 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>). If necessary an exception is raised.

可能的前置算子

thresholdthresholdThresholdThresholdThresholdthreshold, regiongrowingregiongrowingRegiongrowingRegiongrowingRegiongrowingregiongrowing, connectionconnectionConnectionConnectionConnectionconnection

可替代算子

moments_region_2nd_invarmoments_region_2nd_invarMomentsRegion2ndInvarMomentsRegion2ndInvarMomentsRegion2ndInvarmoments_region_2nd_invar

参考其它

elliptic_axiselliptic_axisEllipticAxisEllipticAxisEllipticAxiselliptic_axis

References

R. Haralick, L. Shapiro “Computer and Robot Vision” Addison-Wesley, 1992, pp. 73-75

模块

Foundation

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