Connected components, labeling, centroids, ...

enum	af_rprops_t { AF_RP_Area = 0, AF_RP_Centroid = 1, AF_RP_Orientation = 2, AF_RP_AxisLengths = 4 }
array	regions (const array &image, unsigned connectivity)
	Connected component labeling of a binary image.
array	areas (const array &regions)
	Calculate area of each numbered component in regions.
array	centroids (const array &regions)
	Calculate centroid of each numbered component in regions.
array	moments (const array &regions, af_rprops_t property)
	Calculate property for each numbered component in regions.
void	moments (array &areas, array &centroids, const array &regions)
	Calculate both area and centroid for each numbered component in regions.
void	moments (array &areas, array &centroids, array &axes, array &orientations, const array &regions)
	Calculate various properties for each numbered component in regions.

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Enumeration Type Documentation

enum af_rprops_t

Properties to calculate for every connected component

Enumerator:

AF_RP_Area	[1 x nregions] vector
AF_RP_Centroid	[2 x nregions] vector
AF_RP_Orientation	[1 x nregions] vector
AF_RP_AxisLengths	[2 x nregions] vector

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Function Documentation

array af::regions	(	const array &	image,
		unsigned	connectivity
	)

Connected component labeling of a binary image.

Parameters:

[in]	image	Binary image
[in]	connectivity	either 4 or 8

Returns:

Labeled image (0 is background, regions are 1,2,3,..)

Examples:

examples/image/image_demo.cpp.

array af::areas

(

const array &

regions

)

Calculate area of each numbered component in regions.

Parameters:

[in]

regions

numbered connected components (see regions)

Returns:

row vector of areas (one per region)

Examples:

examples/image/image_demo.cpp.

array af::centroids

(

const array &

regions

)

Calculate centroid of each numbered component in regions.

Parameters:

[in]

regions

numbered connected components (see regions)

Returns:

2xN matrix of centroids (one column per region)

array af::moments	(	const array &	regions,
		af_rprops_t	property
	)

Calculate property for each numbered component in regions.

Parameters:

[in]	regions	numbered connected components (see regions)
[in]	property	(see af_rprops_t), determines output size

Returns:

matrix of properties (one column per region, size depends on property)

Examples:

examples/image/image_demo.cpp.

void af::moments	(	array &	areas,
		array &	centroids,
		const array &	regions
	)

Calculate both area and centroid for each numbered component in regions.

Parameters:

[out]	areas	(1xN vector)
[out]	centroids	(2xN matrix)
[in]	regions	numbered connected components (see regions)

void af::moments	(	array &	areas,
		array &	centroids,
		array &	axes,
		array &	orientations,
		const array &	regions
	)

Calculate various properties for each numbered component in regions.

Parameters:

[out]	areas	(1xN vector)
[out]	centroids	(2xN matrix)
[out]	axes	(2xN matrix)
[out]	orientations	(1xN matrix)
[in]	regions	numbered connected components (see regions)