VXLIB_convolve_7x7_i8u_c16s_o8u

Functions
VXLIB_STATUS	VXLIB_convolve_7x7_i8u_c16s_o8u (const uint8_t src[restrict], const VXLIB_bufParams2D_t *src_addr, uint8_t dst[restrict], const VXLIB_bufParams2D_t *dst_addr, const int16_t conv_mat[restrict], uint32_t shift)
VXLIB_STATUS	VXLIB_convolve_7x7_i8u_c16s_o8u_checkParams (const uint8_t src[restrict], const VXLIB_bufParams2D_t *src_addr, const uint8_t dst[restrict], const VXLIB_bufParams2D_t *dst_addr, const int16_t conv_mat[restrict], uint32_t shift)

Detailed Description

Function Documentation

VXLIB_convolve_7x7_i8u_c16s_o8u()

VXLIB_STATUS VXLIB_convolve_7x7_i8u_c16s_o8u	(	const uint8_t	src[restrict],
		const VXLIB_bufParams2D_t *	src_addr,
		uint8_t	dst[restrict],
		const VXLIB_bufParams2D_t *	dst_addr,
		const int16_t	conv_mat[restrict],
		uint32_t	shift
	)

Description:

Computes a user programmable convolution operation using the 7x7 neighborhood of each input pixel.

Method:

This filter uses the user supplied convolution matrix

Parameters

[in]	src[]	Pointer to array containing input image (UQ8.0)
[in]	src_addr[]	Pointer to structure containing dimensional information of src
[out]	dst[]	Pointer to array containing output image (UQ8.0)
[in]	dst_addr[]	Pointer to structure containing dimensional information of dst
[in]	conv_mat[]	Pointer to array containing the convolution matrix (SQ15.0)
[in]	shift	Value to right shift the sum of products of the 49 neighborhood pixels

Assumptions:

• I/O buffer pointers are assumed to be not aliased.
• Output height should be == (Input height - 6)
• Output width should be == (Input width - 6) OR (Input width)

Performance Considerations:

• For best performance, the following parameter settings are recommended:
  • Set widths equal each other and equal to strides (allows processing over whole image in single loop)
  • Scratch memory of 108 bytes used from stack ... make sure stack is in fast memory.

VXLIB_convolve_7x7_i8u_c16s_o8u_checkParams()

VXLIB_STATUS VXLIB_convolve_7x7_i8u_c16s_o8u_checkParams	(	const uint8_t	src[restrict],
		const VXLIB_bufParams2D_t *	src_addr,
		const uint8_t	dst[restrict],
		const VXLIB_bufParams2D_t *	dst_addr,
		const int16_t	conv_mat[restrict],
		uint32_t	shift
	)

Description:

Checks the parameters for programming errors for the VXLIB_convolve_7x7_i8u_c16s_o8u function.

Method:

The following checks are made:

• There shall be no NULL pointers
• Output height should be == (Input height - 6)
• Output width should be <= Input width
• The strides of each image shall be equal to or greater than the x dimension
• The shift parameter should be <= 31

Parameters

[in]	src[]	Pointer to array containing input image (UQ8.0)
[in]	src_addr[]	Pointer to structure containing dimensional information of src
[out]	dst[]	Pointer to array containing output image (UQ8.0)
[in]	dst_addr[]	Pointer to structure containing dimensional information of dst
[in]	conv_mat[]	Pointer to array containing the convolution matrix (SQ15.0)
[in]	shift	Value to right shift the sum of products of the 49 neighborhood pixels