moments

The af::moments() function allows for finding different properties of image regions. More...

Functions
AFAPI void	moments (double *out, const array &in, const momentType moment=AF_MOMENT_FIRST_ORDER)
	C++ Interface for calculating an image moment. More...
AFAPI array	moments (const array &in, const momentType moment=AF_MOMENT_FIRST_ORDER)
	C++ Interface for calculating image moments. More...
AFAPI af_err	af_moments (af_array *out, const af_array in, const af_moment_type moment)
	C Interface for finding image moments. More...
AFAPI af_err	af_moments_all (double *out, const af_array in, const af_moment_type moment)
	C Interface for calculating image moment(s) of a single image. More...

Detailed Description

The af::moments() function allows for finding different properties of image regions.

Currently, ArrayFire calculates all first order moments. The moments are defined within the af_moment_type enum.

As the enum details, each moment can be returned individually or all first-order moments can be calculated at once. This can be done as follows:

af::array moments = af::moments(input_image, AF_MOMENT_FIRST_ORDER);

Here is an example of how the shorthand versions might be used to find the area(or gray level sum) and center of mass of an image:

double m00, m01, m10;
af::moments(&m00, input_image, AF_MOMENT_M00);
af::moments(&m01, input_image, AF_MOMENT_M01);
af::moments(&m10, input_image, AF_MOMENT_M10);
 
double area = m00;
double x_center = m10 / m00;
double y_center = m01 / m00;

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Function Documentation

af_moments()

AFAPI af_err af_moments	(	af_array *	out,
		const af_array	in,
		const af_moment_type	moment
	)

C Interface for finding image moments.

Parameters

[out]	out	is an array containing the calculated moments
[in]	in	is an array of image(s)
[in]	moment	is moment(s) to calculate

Returns

ref AF_SUCCESS if the moment calculation is successful, otherwise an appropriate error code is returned.

af_moments_all()

AFAPI af_err af_moments_all	(	double *	out,
		const af_array	in,
		const af_moment_type	moment
	)

C Interface for calculating image moment(s) of a single image.

Parameters

[out]	out	is a pointer to a pre-allocated array where the calculated moment(s) will be placed. User is responsible for ensuring enough space to hold all requested moments
[in]	in	is the input image
[in]	moment	is moment(s) to calculate

Returns

ref AF_SUCCESS if the moment calculation is successful, otherwise an appropriate error code is returned.

moments() [1/2]

AFAPI array moments	(	const array &	in,
		const momentType	moment = AF_MOMENT_FIRST_ORDER
	)

C++ Interface for calculating image moments.

Parameters

[in]	in	contains the input image(s)
[in]	moment	is moment(s) to calculate

Returns

array containing the requested moment of each image

moments() [2/2]

AFAPI void moments	(	double *	out,
		const array &	in,
		const momentType	moment = AF_MOMENT_FIRST_ORDER
	)

C++ Interface for calculating an image moment.

Parameters

[out]	out	is a pointer to a pre-allocated array where the calculated moment(s) will be placed. User is responsible for ensuring enough space to hold all requested moments
[in]	in	is the input image
[in]	moment	is moment(s) to calculate