Laplace Filters

Laplace image filters. More...

Functions
SIMD_API void	SimdLaplace (const uint8_t *src, size_t srcStride, size_t width, size_t height, uint8_t *dst, size_t dstStride)
	Calculates a signed 3x3 Laplace filter for an 8-bit gray image. More...
SIMD_API void	SimdLaplaceAbs (const uint8_t *src, size_t srcStride, size_t width, size_t height, uint8_t *dst, size_t dstStride)
	Calculates the absolute value of a 3x3 Laplace filter for an 8-bit gray image. More...
template<template< class > class A>
SIMD_INLINE void	Laplace (const View< A > &src, View< A > &dst)
	Calculates Laplace's filter. More...
template<template< class > class A>
SIMD_INLINE void	LaplaceAbs (const View< A > &src, View< A > &dst)
	Calculates absolute value of Laplace's filter. More...

Detailed Description

Laplace image filters.

Function Documentation

SimdLaplace()

void SimdLaplace	(	const uint8_t *	src,
		size_t	srcStride,
		size_t	width,
		size_t	height,
		uint8_t *	dst,
		size_t	dstStride
	)

Calculates a signed 3x3 Laplace filter for an 8-bit gray image.

The destination image stores signed 16-bit values. The dst pointer is typed as uint8_t for ABI compatibility, but dstStride is measured in bytes and must be compatible with int16_t rows. Border pixels are handled by nearest-pixel replication:

sx0 = Max(x - 1, 0);
sx1 = x;
sx2 = Min(x + 1, width - 1);
sy0 = Max(y - 1, 0);
sy1 = y;
sy2 = Min(y + 1, height - 1);

dst[x, y] = 8*src[sx1, sy1] -
    (src[sx0, sy0] + src[sx1, sy0] + src[sx2, sy0] +
     src[sx0, sy1]                  + src[sx2, sy1] +
     src[sx0, sy2] + src[sx1, sy2] + src[sx2, sy2]);

Note

This function has a C++ wrapper: Simd::Laplace(const View<A>& src, View<A>& dst).

Parameters

[in]	src	- a pointer to pixels data of the input 8-bit gray image.
[in]	srcStride	- a row size of the input image (in bytes).
[in]	width	- an image width. It must be greater than 1.
[in]	height	- an image height.
[out]	dst	- a pointer to pixels data of the output 16-bit signed integer image.
[in]	dstStride	- a row size of the output image (in bytes).

SimdLaplaceAbs()

void SimdLaplaceAbs	(	const uint8_t *	src,
		size_t	srcStride,
		size_t	width,
		size_t	height,
		uint8_t *	dst,
		size_t	dstStride
	)

Calculates the absolute value of a 3x3 Laplace filter for an 8-bit gray image.

The destination image stores signed 16-bit values containing Abs(Laplace(src)). Border pixels are handled by nearest-pixel replication as in SimdLaplace.

Note

This function has a C++ wrapper: Simd::LaplaceAbs(const View<A>& src, View<A>& dst).

Parameters

[in]	src	- a pointer to pixels data of the input 8-bit gray image.
[in]	srcStride	- a row size of the input image (in bytes).
[in]	width	- an image width. It must be greater than 1.
[in]	height	- an image height.
[out]	dst	- a pointer to pixels data of the output 16-bit signed integer image.
[in]	dstStride	- a row size of the output image (in bytes).

Laplace()

void Laplace	(	const View< A > &	src,
		View< A > &	dst
	)

Calculates Laplace's filter.

All images must have the same width and height. Input image must have 8-bit gray format, output image must have 16-bit integer format.

For every point:

dst[x, y] =
    - src[x-1, y-1] -   src[x, y-1] - src[x+1, y-1]
    - src[x-1, y]   + 8*src[x, y]   - src[x+1, y]
    - src[x-1, y+1] -   src[x, y+1] - src[x+1, y+1].

Note

This function is a C++ wrapper for function SimdLaplace.

Parameters

[in]	src	- an input image.
[out]	dst	- an output image.

LaplaceAbs()

void LaplaceAbs	(	const View< A > &	src,
		View< A > &	dst
	)

Calculates absolute value of Laplace's filter.

All images must have the same width and height. Input image must have 8-bit gray format, output image must have 16-bit integer format.

For every point:

dst[x, y] = abs(
    - src[x-1, y-1] -   src[x, y-1] - src[x+1, y-1]
    - src[x-1, y]   + 8*src[x, y]   - src[x+1, y]
    - src[x-1, y+1] -   src[x, y+1] - src[x+1, y+1]).

Note

This function is a C++ wrapper for function SimdLaplaceAbs.

Parameters

[in]	src	- an input image.
[out]	dst	- an output image.