Start » Filter Reference » Region » Region Features » RegionMoment
Basic| Module: | FoundationBasic |
|---|
Computes selected second-order moment of a region in regular and normalized ( divided by region area ) variant.
| Name | Type | Description | |
|---|---|---|---|
 |
inRegion | Region | Input region |
|
inMomentType | RegionMomentType | |
|
inCentral | Bool | |
 |
outMoment | Real | |
|
outNormMoment | Real |
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
This filter can throw an exception to report error. Read how to deal with errors in Error Handling.
List of possible exceptions:
| Error type | Description |
|---|---|
| DomainError | Empty region on input in RegionMoment. |
| DomainError | Not supported moment type in RegionMoment. |
Complexity Level
This filter is available on Basic Complexity Level.
See Also
- PolygonMoment – Computes the selected second-order moment of a polygon in regular and normalized ( divided by polygon area ) variant.
- ImageMoment – Computes the selected moment of an image in regular and normalized (divided by sum of pixel values) variant.