VXLIB_edgeTracing_i8u

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Detailed Description

Functions
VXLIB_STATUS	VXLIB_edgeTracing_i8u (uint8_t edgeMap[], const VXLIB_bufParams2D_t *edgeMap_addr, uint32_t edgeList[], uint32_t edgeListCapacity, uint32_t numEdgesIn, uint32_t *numEdgesOut)
VXLIB_STATUS	VXLIB_edgeTracing_i8u_checkParams (uint8_t edgeMap[], const VXLIB_bufParams2D_t *edgeMap_addr, uint32_t edgeList[], uint32_t edgeListCapacity, uint32_t numEdgesIn, const uint32_t *numEdgesOut)

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Function Documentation

VXLIB_STATUS VXLIB_edgeTracing_i8u	(	uint8_t	edgeMap[],
		const VXLIB_bufParams2D_t *	edgeMap_addr,
		uint32_t	edgeList[],
		uint32_t	edgeListCapacity,
		uint32_t	numEdgesIn,
		uint32_t *	numEdgesOut
	)

Description:

Promotes possible edges to strong edges if they touch strong edges. Since a possible edge can be promoted to a strong edge, the processing must consider possible edges that are touching other possible edges that are promoted to strong edges (a kind of recursive processing).

Method:

For each strong edge in the edgeList array:

• Remove coordinate from list
• Promote possible edges (127) that are in the 8 pixel neighborhood of the strong edge, to a strong edge (255)
• Add the new strong edge to the list for consideration of its neighborhood

Parameters:

[in,out]	edgeMap[]	Pointer to array containing edge map image image (UQ8.0)
[in]	edgeMap_addr[]	Pointer to structure containing dimensional information of edgeMap
[in,out]	edgeList[]	Pointer to array containing list of strong edges This list is modified during processing such that output is not meaningful (UQ32.0)
[in]	edgeListCapacity	Number of entries allocated in the edgeList array
[in]	numEdgesIn	Number of strong edges listed in the edgeList array
[out]	*numEdgesOut	Number of strong edges in the edgeMap after processing is complete.

Assumptions:

• I/O buffer pointers are assumed to be not aliased.
• The one pixel border of edgeMap should all be 0's (non-edges) before calling this function since this function does not support border processing and may perform out of memory access if the border has any non-zeros.
  • The edgeList should also not have any indices of pixels in the one pixel border.

Performance Considerations:

• For best performance, the following parameter settings are recommended:

VXLIB_STATUS VXLIB_edgeTracing_i8u_checkParams	(	uint8_t	edgeMap[],
		const VXLIB_bufParams2D_t *	edgeMap_addr,
		uint32_t	edgeList[],
		uint32_t	edgeListCapacity,
		uint32_t	numEdgesIn,
		const uint32_t *	numEdgesOut
	)

Description:

Checks the parameters for programming errors for the VXLIB_edgeTracing_i8u function.

Method:

The following checks are made:

• There shall be no NULL pointers
• edgeListCapacity shall be > numEdgesIn-8
• The strides of each image shall be equal to or greater than the x dimension

Parameters:

[in,out]	edgeMap[]	Pointer to array containing edge map image image (UQ8.0)
[in]	edgeMap_addr[]	Pointer to structure containing dimensional information of edgeMap
[in,out]	edgeList[]	Pointer to array containing list of strong edges This list is modified during processing such that output is not meaningful (UQ32.0)
[in]	edgeListCapacity	Number of entries allocated in the edgeList array
[in]	numEdgesIn	Number of strong edges listed in the edgeList array
[out]	*numEdgesOut	Number of strong edges in the edgeMap after processing is complete.

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