Back to FabImage Library website
You are here: Start » Function Reference » Region » Region Features » RegionMoment

RegionMoment
Header: | FIL.h |
---|---|
Namespace: | fil |
Module: | FoundationBasic |
Computes selected second-order moment of a region in regular and normalized ( divided by region area ) variant.
Syntax
C++
C#
void fil::RegionMoment ( const fil::Region& inRegion, fil::RegionMomentType::Type inMomentType, bool inCentral, float& outMoment, float& outNormMoment )
Parameters
Name | Type | Default | Description | |
---|---|---|---|---|
![]() |
inRegion | const Region& | Input region | |
![]() |
inMomentType | RegionMomentType::Type | ||
![]() |
inCentral | bool | ||
![]() |
outMoment | float& | ||
![]() |
outNormMoment | float& |
Description
The operation computes the mathematical features of a shape called moments. Those are sums computed as follows:
\[ \begin{aligned} Moment_{2,0}(R) &= \sum_{p \in R} p_x^2 \\ Moment_{1,1}(R) &= \sum_{p \in R} p_x p_y \\ Moment_{0,2}(R) &= \sum_{p \in R} p_y^2 \end{aligned} \]The summing is conducted over region pixels, while \( p_x \) and \( p_y \) denote, accordingly, x and y coordinate of a pixel.
When inCentral parameter is set, the region is shifted before computations, so that its mass center is at location (0,0).
Hints
- If the input region is not guaranteed to be non-empty, precede this filter with SkipEmptyRegion.
Errors
List of possible exceptions:
Error type | Description |
---|---|
DomainError | Empty region on input in RegionMoment. |
DomainError | Not supported moment type in RegionMoment. |
See Also
- ImageMoment – Computes the selected moment of an image in regular and normalized (divided by sum of pixel values) variant.