Moments

1:st and 2:nd order moments for binary images. More...

Functions
int	rapp_moment_order1_bin (const uint8_t *buf, int dim, int width, int height, uint32_t mom[3])
	First order binary image moments.
int	rapp_moment_order2_bin (const uint8_t *buf, int dim, int width, int height, uintmax_t mom[6])
	First and second order binary image moments.

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Detailed Description

1:st and 2:nd order moments for binary images.

All moments are image-global. The functions may read data up to the nearest alignment boundary, so if those pixels are not properly cleared the output may be invalid.

The performance of these functions is input-sensitive, with the best case occurring for images with all-zero pixels. The worst case is a dense, but not contiguous pattern, e.g. a checker board pattern. For actual performance figures, see the benchmark plots.

All images must be aligned.

Next section: Spatial Filtering

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Function Documentation

int rapp_moment_order1_bin	(	const uint8_t *	buf,
		int	dim,
		int	width,
		int	height,
		uint32_t	mom[3]
	)

First order binary image moments.

The result is only valid if it is not greater than 2³².

Parameters:

[in]	buf	Source pixel buffer.
	dim	Row dimension of the source buffer.
	width	Image width in pixels.
	height	Image height in pixels.
[out]	mom	Storage array for the moment output with at least 3 elements. It is filled in the following way: mom[0]: moment of order 0 (pixel sum) mom[1]: 1:st order moment (x) mom[2]: 1:st order moment (y)

Returns:

A negative error code on error, zero otherwise.

int rapp_moment_order2_bin	(	const uint8_t *	buf,
		int	dim,
		int	width,
		int	height,
		uintmax_t	mom[6]
	)

First and second order binary image moments.

The 1:st and 2:nd order moments are only valid if they are not greater than 2³² and 2^{8*sizeof(uintmax_t)}, respectively.

Parameters:

[in]	buf	Source pixel buffer.
	dim	Row dimension of the source buffer.
	width	Image width in pixels.
	height	Image height in pixels.
[out]	mom	Storage array for the moment output with at least 6 elements. It is filled in the following way: mom[0]: moment of order 0 (pixel sum) mom[1]: 1:st order moment (x) mom[2]: 1:st order moment (y) mom[3]: 2:nd order moment (x) mom[4]: 2:nd order moment (y) mom[5]: 2:nd order moment (xy)

Returns:

A negative error code on error, zero otherwise.