Spatial Reduction

Perform 2x spatial reductions. More...

int	rapp_reduce_1x2_u8 (uint8_t *restrict dst, int dst_dim, const uint8_t *restrict src, int src_dim, int width, int height)
	8-bit 1x2 (horizontal) resolution reduction.
int	rapp_reduce_2x1_u8 (uint8_t *restrict dst, int dst_dim, const uint8_t *restrict src, int src_dim, int width, int height)
	8-bit 2x1 (vertical) reduction.
int	rapp_reduce_2x2_u8 (uint8_t *restrict dst, int dst_dim, const uint8_t *restrict src, int src_dim, int width, int height)
	8-bit 2x2 reduction.
int	rapp_reduce_1x2_rk1_bin (uint8_t *restrict dst, int dst_dim, const uint8_t *restrict src, int src_dim, int width, int height)
	Binary 1x2 reduction, rank 1.
int	rapp_reduce_1x2_rk2_bin (uint8_t *restrict dst, int dst_dim, const uint8_t *restrict src, int src_dim, int width, int height)
	Binary 1x2 reduction, rank 2.
int	rapp_reduce_2x1_rk1_bin (uint8_t *restrict dst, int dst_dim, const uint8_t *restrict src, int src_dim, int width, int height)
	Binary 2x1 reduction, rank 1.
int	rapp_reduce_2x1_rk2_bin (uint8_t *restrict dst, int dst_dim, const uint8_t *restrict src, int src_dim, int width, int height)
	Binary 2x1 reduction, rank 2.
int	rapp_reduce_2x2_rk1_bin (uint8_t *restrict dst, int dst_dim, const uint8_t *restrict src, int src_dim, int width, int height)
	Binary 2x2 reduction, rank 1.
int	rapp_reduce_2x2_rk2_bin (uint8_t *restrict dst, int dst_dim, const uint8_t *restrict src, int src_dim, int width, int height)
	Binary 2x2 reduction, rank 2.
int	rapp_reduce_2x2_rk3_bin (uint8_t *restrict dst, int dst_dim, const uint8_t *restrict src, int src_dim, int width, int height)
	Binary 2x2 reduction, rank 3.
int	rapp_reduce_2x2_rk4_bin (uint8_t *restrict dst, int dst_dim, const uint8_t *restrict src, int src_dim, int width, int height)
	Binary 2x2 reduction, rank 4.

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Detailed Description

Perform 2x spatial reductions.

All images must be aligned.

Next section: Spatial Expansion

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Function Documentation

int rapp_reduce_1x2_u8	(	uint8_t *restrict	dst,
		int	dst_dim,
		const uint8_t *restrict	src,
		int	src_dim,
		int	width,
		int	height
	)

8-bit 1x2 (horizontal) resolution reduction.

Downscaling to half size in horizontal direction by averaging. The size of the reduced image is width/2, height, rounded down.

Parameters:

[out]	dst	Destination pixel buffer.
	dst_dim	Row dimension of the destination buffer.
[in]	src	Source pixel buffer.
	src_dim	Row dimension of the source buffer.
	width	Source image width in pixels.
	height	Image height in pixels.

Returns:

A negative error code on error, zero otherwise.

int rapp_reduce_1x2_rk1_bin	(	uint8_t *restrict	dst,
		int	dst_dim,
		const uint8_t *restrict	src,
		int	src_dim,
		int	width,
		int	height
	)

Binary 1x2 reduction, rank 1.

Downscaling to half size in horizontal direction. A destination pixel is set iff the sum of the source pixels in the 1x2 cell is at least 1. The size of the reduced image is width/2, height, rounded down.

Parameters:

[out]	dst	Destination pixel buffer.
	dst_dim	Row dimension of the destination buffer.
[in]	src	Source pixel buffer.
	src_dim	Row dimension of the source buffer.
	width	Source image width in pixels.
	height	Image height in pixels.

Returns:

A negative error code on error, zero otherwise.

int rapp_reduce_2x1_u8	(	uint8_t *restrict	dst,
		int	dst_dim,
		const uint8_t *restrict	src,
		int	src_dim,
		int	width,
		int	height
	)

8-bit 2x1 (vertical) reduction.

Downscaling to half size in vertical direction by averaging. The size of the reduced image is width, height/2, rounded down.

Parameters:

[out]	dst	Destination pixel buffer.
	dst_dim	Row dimension of the destination buffer.
[in]	src	Source pixel buffer.
	src_dim	Row dimension of the source buffer.
	width	Image width in pixels.
	height	Source image height in pixels.

Returns:

A negative error code on error, zero otherwise.

int rapp_reduce_2x2_u8	(	uint8_t *restrict	dst,
		int	dst_dim,
		const uint8_t *restrict	src,
		int	src_dim,
		int	width,
		int	height
	)

8-bit 2x2 reduction.

Downscaling to half size by averaging. The size of the reduced image is width/2, height/2, rounded down.

Parameters:

[out]	dst	Destination pixel buffer.
	dst_dim	Row dimension of the destination buffer.
[in]	src	Source pixel buffer.
	src_dim	Row dimension of the source buffer.
	width	Source image width in pixels.
	height	Source image height in pixels.

Returns:

A negative error code on error, zero otherwise.

int rapp_reduce_1x2_rk2_bin	(	uint8_t *restrict	dst,
		int	dst_dim,
		const uint8_t *restrict	src,
		int	src_dim,
		int	width,
		int	height
	)

Binary 1x2 reduction, rank 2.

Downscaling to half size in horizontal direction. A destination pixel is set iff the sum of the source pixels in the 1x2 cell is 2. The size of the reduced image is width/2, height, rounded down.

Parameters:

[out]	dst	Destination pixel buffer.
	dst_dim	Row dimension of the destination buffer.
[in]	src	Source pixel buffer.
	src_dim	Row dimension of the source buffer.
	width	Source image width in pixels.
	height	Image height in pixels.

Returns:

A negative error code on error, zero otherwise.

int rapp_reduce_2x1_rk1_bin	(	uint8_t *restrict	dst,
		int	dst_dim,
		const uint8_t *restrict	src,
		int	src_dim,
		int	width,
		int	height
	)

Binary 2x1 reduction, rank 1.

Downscaling to half size in vertical direction. A destination pixel is set iff the sum of the source pixels in the 2x1 cell is at least 1. The size of the reduced image is width, height/2, rounded down.

Parameters:

[out]	dst	Destination pixel buffer.
	dst_dim	Row dimension of the destination buffer.
[in]	src	Source pixel buffer.
	src_dim	Row dimension of the source buffer.
	width	Source image width in pixels.
	height	Image height in pixels.

Returns:

A negative error code on error, zero otherwise.

int rapp_reduce_2x1_rk2_bin	(	uint8_t *restrict	dst,
		int	dst_dim,
		const uint8_t *restrict	src,
		int	src_dim,
		int	width,
		int	height
	)

Binary 2x1 reduction, rank 2.

Downscaling to half size in vertical direction. A destination pixel is set iff the sum of the source pixels in the 2x1 cell is 2. The size of the reduced image is width, height/2, rounded down.

Parameters:

[out]	dst	Destination pixel buffer.
	dst_dim	Row dimension of the destination buffer.
[in]	src	Source pixel buffer.
	src_dim	Row dimension of the source buffer.
	width	Source image width in pixels.
	height	Image height in pixels.

Returns:

A negative error code on error, zero otherwise.

int rapp_reduce_2x2_rk1_bin	(	uint8_t *restrict	dst,
		int	dst_dim,
		const uint8_t *restrict	src,
		int	src_dim,
		int	width,
		int	height
	)

Binary 2x2 reduction, rank 1.

Downscaling to half size in vertical direction. A destination pixel is set iff the sum of the source pixels in the 2x2 cell is at least 1. The size of the reduced image is width/2, height/2, rounded down.

Parameters:

[out]	dst	Destination pixel buffer.
	dst_dim	Row dimension of the destination buffer.
[in]	src	Source pixel buffer.
	src_dim	Row dimension of the source buffer.
	width	Source image width in pixels.
	height	Image height in pixels.

Returns:

A negative error code on error, zero otherwise.

int rapp_reduce_2x2_rk2_bin	(	uint8_t *restrict	dst,
		int	dst_dim,
		const uint8_t *restrict	src,
		int	src_dim,
		int	width,
		int	height
	)

Binary 2x2 reduction, rank 2.

Downscaling to half size in vertical direction. A destination pixel is set iff the sum of the source pixels in the 2x2 cell is at least 2. The size of the reduced image is width/2, height/2, rounded down.

Parameters:

[out]	dst	Destination pixel buffer.
	dst_dim	Row dimension of the destination buffer.
[in]	src	Source pixel buffer.
	src_dim	Row dimension of the source buffer.
	width	Source image width in pixels.
	height	Image height in pixels.

Returns:

A negative error code on error, zero otherwise.

int rapp_reduce_2x2_rk3_bin	(	uint8_t *restrict	dst,
		int	dst_dim,
		const uint8_t *restrict	src,
		int	src_dim,
		int	width,
		int	height
	)

Binary 2x2 reduction, rank 3.

Downscaling to half size in vertical direction. A destination pixel is set iff the sum of the source pixels in the 2x2 cell is at least 3. The size of the reduced image is width/2, height/2, rounded down.

Parameters:

[out]	dst	Destination pixel buffer.
	dst_dim	Row dimension of the destination buffer.
[in]	src	Source pixel buffer.
	src_dim	Row dimension of the source buffer.
	width	Source image width in pixels.
	height	Image height in pixels.

Returns:

A negative error code on error, zero otherwise.

int rapp_reduce_2x2_rk4_bin	(	uint8_t *restrict	dst,
		int	dst_dim,
		const uint8_t *restrict	src,
		int	src_dim,
		int	width,
		int	height
	)

Binary 2x2 reduction, rank 4.

Downscaling to half size in vertical direction. A destination pixel is set iff the sum of the source pixels in the 2x2 cell is 4. The size of the reduced image is width/2, height/2, rounded down.

Parameters:

[out]	dst	Destination pixel buffer.
	dst_dim	Row dimension of the destination buffer.
[in]	src	Source pixel buffer.
	src_dim	Row dimension of the source buffer.
	width	Source image width in pixels.
	height	Image height in pixels.

Returns:

A negative error code on error, zero otherwise.