VXLIB_equalizeHist_i8u_o8u

Functions
VXLIB_STATUS	VXLIB_equalizeHist_i8u_o8u (const uint8_t src[restrict], const VXLIB_bufParams2D_t *src_addr, uint8_t dst[restrict], const VXLIB_bufParams2D_t *dst_addr, uint32_t scratch[restrict])
VXLIB_STATUS	VXLIB_equalizeHist_i8u_o8u_checkParams (const uint8_t src[], const VXLIB_bufParams2D_t *src_addr, const uint8_t dst[], const VXLIB_bufParams2D_t *dst_addr, const uint32_t scratch[restrict])

Detailed Description

Function Documentation

VXLIB_equalizeHist_i8u_o8u()

VXLIB_STATUS VXLIB_equalizeHist_i8u_o8u	(	const uint8_t	src[restrict],
		const VXLIB_bufParams2D_t *	src_addr,
		uint8_t	dst[restrict],
		const VXLIB_bufParams2D_t *	dst_addr,
		uint32_t	scratch[restrict]
	)

Description:

Equalizes the histogram of a grayscale image.

Parameters

[in]	src[]	Pointer to array containing first 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,out]	scratch[]	Pointer to array containing the intermediate distribution data (UQ32.0)

Assumptions:

• I/O buffer pointers are assumed to be not aliased.
• scratch buffer assumed to have 1024 entries
• scratch buffer pointer assumed to be 8-byte aligned.
• PARAMETER INITIALIZATION:
  • All scratch entries should be externally initialized to zero before calling the function each time.

Performance Considerations:

• For best performance, the following parameter settings are recommended:
  • Set widths equal to strides
  • Align src pointer to 4 byte boundaries
  • Set all stride values to a multiple of 8
  • Set all width values to a multiple of 8
  • If a user wants to divide processing of the image into smaller blocks, then user should instead call 3 different functions instead of this function:
    1. VXLIB_histogramSimple_i8u_o32u (for every block in the image)
    2. VXLIB_histogramCdfLut_i32u_o8u (once on the final output histogram of VXLIB_histogramSimple_i8u_o32u)
    3. VXLIB_tableLookup_i8u_o8u (for every block in the image)

VXLIB_equalizeHist_i8u_o8u_checkParams()

VXLIB_STATUS VXLIB_equalizeHist_i8u_o8u_checkParams	(	const uint8_t	src[],
		const VXLIB_bufParams2D_t *	src_addr,
		const uint8_t	dst[],
		const VXLIB_bufParams2D_t *	dst_addr,
		const uint32_t	scratch[restrict]
	)

Description:

Checks the parameters for programming errors for the VXLIB_equalizeHist_i8u_o8u function.

Method:

The following checks are made:

• There shall be no NULL pointers
• All images shall have the same x and y dimensions
• 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
[in,out]	scratch[]	Pointer to array containing the intermediate distribution data (UQ32.0)