Canny Edge Detector

Runs the canny edge detector algorithm over the input image. More...

Data Structures
struct	VPICannyEdgeDetectorParams
	Structure that defines the parameters for vpiSubmitCannyEdgeDetector. More...

Functions
VPIStatus	vpiCreateCannyEdgeDetector (uint64_t backends, int32_t imageWidth, int32_t imageHeight, VPIPayload *payload)
	Creates payload for vpiSubmitCannyEdgeDetector. More...
VPIStatus	vpiInitCannyEdgeDetectorParams (VPICannyEdgeDetectorParams *params)
	Initialize vpiInitCannyEdgeDetectorParams with default values. More...
VPIStatus	vpiSubmitCannyEdgeDetector (VPIStream stream, uint64_t backend, VPIPayload payload, VPIImage input, VPIImage output, float thresholdStrong, float thresholdWeak, float edgeValue, float nonEdgeValue, const VPICannyEdgeDetectorParams *params)
	Runs the canny edge detector algorithm over an image. More...

Detailed Description

Runs the canny edge detector algorithm over the input image.

Refer to Canny edge detector for more details and usage examples.

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Data Structure Documentation

VPICannyEdgeDetectorParams

struct VPICannyEdgeDetectorParams

Structure that defines the parameters for vpiSubmitCannyEdgeDetector.

Definition at line 107 of file CannyEdges.h.

Collaboration diagram for VPICannyEdgeDetectorParams:

Data Fields
VPINormType	normType	Determine the norm to calculate the gradient intensity.
VPIGradientMethod	gradMethod	Specify the method used to generate gradient from the input image.
int32_t	gradientSize	Gradient window size. Must be 3, 5 or 7.

Function Documentation

vpiCreateCannyEdgeDetector()

VPIStatus vpiCreateCannyEdgeDetector	(	uint64_t	backends,
		int32_t	imageWidth,
		int32_t	imageHeight,
		VPIPayload *	payload
	)

#include </opt/nvidia/vpi3/include/vpi/algo/CannyEdges.h>

Creates payload for vpiSubmitCannyEdgeDetector.

Parameters

[in]	backends	VPI backends that are eligible to execute the algorithm. Valid values: VPI_BACKEND_CPU VPI_BACKEND_CUDA Backend must be enabled in current context.
[in]	imageWidth,imageHeight	Input image dimensions. Must be >= 1x1.
[out]	payload	Pointer to the payload variable that receives the created handle.

Return values

VPI_ERROR_INVALID_ARGUMENT	payload is NULL.
VPI_ERROR_INVALID_ARGUMENT	imageWidth and imageHeight outside valid range.
VPI_ERROR_INVALID_ARGUMENT	backends refers to an invalid backend.
VPI_ERROR_INVALID_OPERATION	Backend isn't enabled in current context.
VPI_ERROR_NOT_IMPLEMENTED	Canny edge detector algorithm is not supported by given backend.
VPI_ERROR_INVALID_CONTEXT	Current context is destroyed.
VPI_ERROR_OUT_OF_MEMORY	Cannot allocate required resources.
VPI_SUCCESS	Operation executed successfully.

vpiInitCannyEdgeDetectorParams()

VPIStatus vpiInitCannyEdgeDetectorParams

(

VPICannyEdgeDetectorParams *

params

)

#include </opt/nvidia/vpi3/include/vpi/algo/CannyEdges.h>

Initialize vpiInitCannyEdgeDetectorParams with default values.

Default values:

• normType: VPI_NORM_L2
• gradMethod: GEN_GRADIENT_SOBEL
• gradientSize: 3

Parameters

[out]

params

Structure to be filled with default values.

Returns

an error code on failure else VPI_SUCCESS.

vpiSubmitCannyEdgeDetector()

VPIStatus vpiSubmitCannyEdgeDetector	(	VPIStream	stream,
		uint64_t	backend,
		VPIPayload	payload,
		VPIImage	input,
		VPIImage	output,
		float	thresholdStrong,
		float	thresholdWeak,
		float	edgeValue,
		float	nonEdgeValue,
		const VPICannyEdgeDetectorParams *	params
	)

#include </opt/nvidia/vpi3/include/vpi/algo/CannyEdges.h>

Runs the canny edge detector algorithm over an image.

Parameters

[in]	stream	A stream handle where the operation will be queued into. Must not be NULL. Stream must have enabled the backends that will execute the algorithm.
[in]	backend	Backend that will execute the algorithm. Valid values: VPI_BACKEND_CPU VPI_BACKEND_CUDA
[in]	payload	Pointer to the payload variable that receives the created handle.
[in]	input	Input image. Must not be NULL. Image must have enabled the backends that will execute the algorithm. The accepted image formats are: Format CPU CUDA VPI_IMAGE_FORMAT_U8 * * VPI_IMAGE_FORMAT_S8 * * VPI_IMAGE_FORMAT_U16 * * VPI_IMAGE_FORMAT_S16 * * VPI_IMAGE_FORMAT_F32 * * VPI_IMAGE_FORMAT_Y8_ER * * VPI_IMAGE_FORMAT_Y8 * * VPI_IMAGE_FORMAT_Y16_ER * * VPI_IMAGE_FORMAT_Y16 * *
[out]	output	Output image where the result is written to. Must not be NULL. It must have same dimensions as input image. Image must have enabled the backends that will execute the algorithm. The accepted formats are the same as input
[in]	thresholdStrong	Strong threshold for the hysteresis procedure.
[in]	thresholdWeak	Weak threshold for the hysteresis procedure.
[in]	edgeValue	Value used to mark edge. This value should be different than nonEdgeValue. This value will be clamped if it exceeds the value range of the output image.
[in]	nonEdgeValue	Value used to mark non-edge. This value should be different than edgeValue. This value will be clamped if it exceeds the value range of the output image.
[in]	params	Control parameters of the canny edge detector algorithm.

Return values

VPI_ERROR_INVALID_ARGUMENT	stream is NULL.
VPI_ERROR_INVALID_ARGUMENT	input or output are NULL.
VPI_ERROR_INVALID_ARGUMENT	input or output image dimensions ouside valid range.
VPI_ERROR_INVALID_ARGUMENT	backend is invalid or unknown.
VPI_ERROR_INVALID_IMAGE_FORMAT	input or output image format not supported.
VPI_ERROR_INVALID_OPERATION	Backend hardware is not available.
VPI_ERROR_INVALID_OPERATION	The needed backends aren't enabled in stream, input or output.
VPI_ERROR_NOT_IMPLEMENTED	Canny edge detector algorithm is not supported by given backend.
VPI_SUCCESS	Operation executed successfully.