VXLIB_halfScaleGaussian_5x5_i8u_o8u

Functions
VXLIB_STATUS	VXLIB_halfScaleGaussian_5x5_i8u_o8u (const uint8_t src[restrict], const VXLIB_bufParams2D_t *src_addr, uint8_t dst[restrict], const VXLIB_bufParams2D_t *dst_addr)
VXLIB_STATUS	VXLIB_halfScaleGaussian_5x5_i8u_o8u_checkParams (const uint8_t src[restrict], const VXLIB_bufParams2D_t *src_addr, const uint8_t dst[restrict], const VXLIB_bufParams2D_t *dst_addr)

Detailed Description

Function Documentation

VXLIB_halfScaleGaussian_5x5_i8u_o8u()

VXLIB_STATUS VXLIB_halfScaleGaussian_5x5_i8u_o8u	(	const uint8_t	src[restrict],
		const VXLIB_bufParams2D_t *	src_addr,
		uint8_t	dst[restrict],
		const VXLIB_bufParams2D_t *	dst_addr
	)

Description:

Computes a gaussian filter over the 5x5 neighborhood of each input pixel, then half scales the image in both horizontal and vertical using nearest neighbor interpolation.

Method:

This filter uses the following convolution matrix:

         | 1  4  6  4  1 |
         | 4 16 24 16  4 |
    K =  | 6 24 36 24  6 | * 1/256
         | 4 16 24 16  4 |
         | 1  4  6  4  1 |

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

Assumptions:

• I/O buffer pointers are assumed to be not aliased.
• Input width should be >= (Output width + 2) * 2
• Input height should be == (Output height + 2) * 2

• When breaking input image processing into blocks, be sure to fetch enough overlap pixels from the input for interior edges for the rescale, or else the function may put a false border within the block edge of of the output image. For each dimension, the required fetch amount should be:

  • input block width to fetch = (output block width + 2) * 2
  • input block height to fetch = (output block height + 2) * 2

  And the amount of left/top overlap to refetch should be:

  • left edge overlap = 2
  • top edge overlap = 2

VXLIB_halfScaleGaussian_5x5_i8u_o8u_checkParams()

VXLIB_STATUS VXLIB_halfScaleGaussian_5x5_i8u_o8u_checkParams	(	const uint8_t	src[restrict],
		const VXLIB_bufParams2D_t *	src_addr,
		const uint8_t	dst[restrict],
		const VXLIB_bufParams2D_t *	dst_addr
	)

Description:

Checks the parameters for programming errors for the VXLIB_halfScaleGaussian_5x5_i8u_o8u function.

Method:

The following checks are made:

• There shall be no NULL pointers
• Input width should be >= (Output width + 2) * 2
• Input height should be == (Output height + 2) * 2
• The strides of each image shall be equal to or greater than the x dimension

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