cv::cuda::NvidiaOpticalFlow_2_0 Class Reference

Class for computing the optical flow vectors between two images using NVIDIA Optical Flow hardware and Optical Flow SDK 2.0. More...

#include <opencv2/cudaoptflow.hpp>

Collaboration diagram for cv::cuda::NvidiaOpticalFlow_2_0:

Public Types
enum	NVIDIA_OF_HINT_VECTOR_GRID_SIZE {   NV_OF_HINT_VECTOR_GRID_SIZE_UNDEFINED ,   NV_OF_HINT_VECTOR_GRID_SIZE_1 = 1 ,   NV_OF_HINT_VECTOR_GRID_SIZE_2 = 2 ,   NV_OF_HINT_VECTOR_GRID_SIZE_4 = 4 ,   NV_OF_HINT_VECTOR_GRID_SIZE_8 = 8 ,   NV_OF_HINT_VECTOR_GRID_SIZE_MAX }
enum	NVIDIA_OF_OUTPUT_VECTOR_GRID_SIZE {   NV_OF_OUTPUT_VECTOR_GRID_SIZE_UNDEFINED ,   NV_OF_OUTPUT_VECTOR_GRID_SIZE_1 = 1 ,   NV_OF_OUTPUT_VECTOR_GRID_SIZE_2 = 2 ,   NV_OF_OUTPUT_VECTOR_GRID_SIZE_4 = 4 ,   NV_OF_OUTPUT_VECTOR_GRID_SIZE_MAX }
enum	NVIDIA_OF_PERF_LEVEL {   NV_OF_PERF_LEVEL_UNDEFINED ,   NV_OF_PERF_LEVEL_SLOW = 5 ,   NV_OF_PERF_LEVEL_MEDIUM = 10 ,   NV_OF_PERF_LEVEL_FAST = 20 ,   NV_OF_PERF_LEVEL_MAX }

Public Member Functions
virtual void	convertToFloat (InputArray flow, InputOutputArray floatFlow)=0
	convertToFloat() helper function converts the hardware-generated flow vectors to floating point representation (1 flow vector for gridSize). gridSize can be queried via function getGridSize().
Public Member Functions inherited from cv::cuda::NvidiaHWOpticalFlow
virtual void	calc (InputArray inputImage, InputArray referenceImage, InputOutputArray flow, Stream &stream=Stream::Null(), InputArray hint=cv::noArray(), OutputArray cost=cv::noArray())=0
	Calculates Optical Flow using NVIDIA Optical Flow SDK.
virtual void	collectGarbage ()=0
	Releases all buffers, contexts and device pointers.
virtual int	getGridSize () const =0
	Returns grid size of output buffer as per the hardware's capability.
Public Member Functions inherited from cv::Algorithm
	Algorithm ()
virtual	~Algorithm ()
virtual void	clear ()
	Clears the algorithm state.
virtual bool	empty () const
	Returns true if the Algorithm is empty (e.g. in the very beginning or after unsuccessful read.
virtual String	getDefaultName () const
virtual void	read (const FileNode &fn)
	Reads algorithm parameters from a file storage.
virtual void	save (const String &filename) const
void	write (const Ptr< FileStorage > &fs, const String &name=String()) const
virtual void	write (FileStorage &fs) const
	Stores algorithm parameters in a file storage.
void	write (FileStorage &fs, const String &name) const

Static Public Member Functions
static Ptr< NvidiaOpticalFlow_2_0 >	create (cv::Size imageSize, cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_PERF_LEVEL perfPreset=cv::cuda::NvidiaOpticalFlow_2_0::NV_OF_PERF_LEVEL_SLOW, cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_OUTPUT_VECTOR_GRID_SIZE outputGridSize=cv::cuda::NvidiaOpticalFlow_2_0::NV_OF_OUTPUT_VECTOR_GRID_SIZE_1, cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_HINT_VECTOR_GRID_SIZE hintGridSize=cv::cuda::NvidiaOpticalFlow_2_0::NV_OF_HINT_VECTOR_GRID_SIZE_1, bool enableTemporalHints=false, bool enableExternalHints=false, bool enableCostBuffer=false, int gpuId=0, Stream &inputStream=Stream::Null(), Stream &outputStream=Stream::Null())
	Instantiate NVIDIA Optical Flow.
static Ptr< NvidiaOpticalFlow_2_0 >	create (cv::Size imageSize, std::vector< Rect > roiData, cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_PERF_LEVEL perfPreset=cv::cuda::NvidiaOpticalFlow_2_0::NV_OF_PERF_LEVEL_SLOW, cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_OUTPUT_VECTOR_GRID_SIZE outputGridSize=cv::cuda::NvidiaOpticalFlow_2_0::NV_OF_OUTPUT_VECTOR_GRID_SIZE_1, cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_HINT_VECTOR_GRID_SIZE hintGridSize=cv::cuda::NvidiaOpticalFlow_2_0::NV_OF_HINT_VECTOR_GRID_SIZE_1, bool enableTemporalHints=false, bool enableExternalHints=false, bool enableCostBuffer=false, int gpuId=0, Stream &inputStream=Stream::Null(), Stream &outputStream=Stream::Null())
	Instantiate NVIDIA Optical Flow with ROI Feature.
Static Public Member Functions inherited from cv::Algorithm
template<typename _Tp >
static Ptr< _Tp >	load (const String &filename, const String &objname=String())
	Loads algorithm from the file.
template<typename _Tp >
static Ptr< _Tp >	loadFromString (const String &strModel, const String &objname=String())
	Loads algorithm from a String.
template<typename _Tp >
static Ptr< _Tp >	read (const FileNode &fn)
	Reads algorithm from the file node.

Additional Inherited Members
Protected Member Functions inherited from cv::Algorithm
void	writeFormat (FileStorage &fs) const

Detailed Description

Class for computing the optical flow vectors between two images using NVIDIA Optical Flow hardware and Optical Flow SDK 2.0.

Note

• A sample application demonstrating the use of NVIDIA Optical Flow can be found at opencv_contrib_source_code/modules/cudaoptflow/samples/nvidia_optical_flow.cpp
• An example application comparing accuracy and performance of NVIDIA Optical Flow with other optical flow algorithms in OpenCV can be found at opencv_contrib_source_code/modules/cudaoptflow/samples/optical_flow.cpp

Member Enumeration Documentation

NVIDIA_OF_HINT_VECTOR_GRID_SIZE

enum cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_HINT_VECTOR_GRID_SIZE

Supported grid size for hint buffer.

Enumerator
NV_OF_HINT_VECTOR_GRID_SIZE_UNDEFINED
NV_OF_HINT_VECTOR_GRID_SIZE_1	Hint buffer grid size is 1x1.
NV_OF_HINT_VECTOR_GRID_SIZE_2	Hint buffer grid size is 2x2.
NV_OF_HINT_VECTOR_GRID_SIZE_4	Hint buffer grid size is 4x4.
NV_OF_HINT_VECTOR_GRID_SIZE_8	Hint buffer grid size is 8x8.
NV_OF_HINT_VECTOR_GRID_SIZE_MAX

NVIDIA_OF_OUTPUT_VECTOR_GRID_SIZE

enum cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_OUTPUT_VECTOR_GRID_SIZE

Supported grid size for output buffer.

Enumerator
NV_OF_OUTPUT_VECTOR_GRID_SIZE_UNDEFINED
NV_OF_OUTPUT_VECTOR_GRID_SIZE_1	Output buffer grid size is 1x1
NV_OF_OUTPUT_VECTOR_GRID_SIZE_2	Output buffer grid size is 2x2
NV_OF_OUTPUT_VECTOR_GRID_SIZE_4	Output buffer grid size is 4x4
NV_OF_OUTPUT_VECTOR_GRID_SIZE_MAX

NVIDIA_OF_PERF_LEVEL

enum cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_PERF_LEVEL

Supported optical flow performance levels.

Enumerator
NV_OF_PERF_LEVEL_UNDEFINED
NV_OF_PERF_LEVEL_SLOW	Slow perf level results in lowest performance and best quality
NV_OF_PERF_LEVEL_MEDIUM	Medium perf level results in low performance and medium quality
NV_OF_PERF_LEVEL_FAST	Fast perf level results in high performance and low quality
NV_OF_PERF_LEVEL_MAX

Member Function Documentation

convertToFloat()

virtual void cv::cuda::NvidiaOpticalFlow_2_0::convertToFloat ( InputArray flow, InputOutputArray floatFlow )

pure virtual

convertToFloat() helper function converts the hardware-generated flow vectors to floating point representation (1 flow vector for gridSize). gridSize can be queried via function getGridSize().

Parameters

flow	Buffer of type CV_16FC2 containing flow vectors generated by calc().
floatFlow	Buffer of type CV_32FC2, containing flow vectors in floating point representation, each flow vector for 1 pixel per gridSize, in the pitch-linear layout.

create() [1/2]

static Ptr< NvidiaOpticalFlow_2_0 > cv::cuda::NvidiaOpticalFlow_2_0::create ( cv::Size imageSize, cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_PERF_LEVEL perfPreset = cv::cuda::NvidiaOpticalFlow_2_0::NV_OF_PERF_LEVEL_SLOW, cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_OUTPUT_VECTOR_GRID_SIZE outputGridSize = cv::cuda::NvidiaOpticalFlow_2_0::NV_OF_OUTPUT_VECTOR_GRID_SIZE_1, cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_HINT_VECTOR_GRID_SIZE hintGridSize = cv::cuda::NvidiaOpticalFlow_2_0::NV_OF_HINT_VECTOR_GRID_SIZE_1, bool enableTemporalHints = false, bool enableExternalHints = false, bool enableCostBuffer = false, int gpuId = 0, Stream & inputStream = Stream::Null(), Stream & outputStream = Stream::Null() )

static

Instantiate NVIDIA Optical Flow.

Parameters

imageSize	Size of input image in pixels.
perfPreset	Optional parameter. Refer NV OF SDK documentation for details about presets. Defaults to NV_OF_PERF_LEVEL_SLOW.
outputGridSize	Optional parameter. Refer NV OF SDK documentation for details about output grid sizes. Defaults to NV_OF_OUTPUT_VECTOR_GRID_SIZE_1.
hintGridSize	Optional parameter. Refer NV OF SDK documentation for details about hint grid sizes. Defaults to NV_OF_HINT_VECTOR_GRID_SIZE_1.
enableTemporalHints	Optional parameter. Flag to enable temporal hints. When set to true, the hardware uses the flow vectors generated in previous call to calc() as internal hints for the current call to calc(). Useful when computing flow vectors between successive video frames. Defaults to false.
enableExternalHints	Optional Parameter. Flag to enable passing external hints buffer to calc(). Defaults to false.
enableCostBuffer	Optional Parameter. Flag to enable cost buffer output from calc(). Defaults to false.
gpuId	Optional parameter to select the GPU ID on which the optical flow should be computed. Useful in multi-GPU systems. Defaults to 0.
inputStream	Optical flow algorithm may optionally involve cuda preprocessing on the input buffers. The input cuda stream can be used to pipeline and synchronize the cuda preprocessing tasks with OF HW engine. If input stream is not set, the execute function will use default stream which is NULL stream;
outputStream	Optical flow algorithm may optionally involve cuda post processing on the output flow vectors. The output cuda stream can be used to pipeline and synchronize the cuda post processing tasks with OF HW engine. If output stream is not set, the execute function will use default stream which is NULL stream;

create() [2/2]

static Ptr< NvidiaOpticalFlow_2_0 > cv::cuda::NvidiaOpticalFlow_2_0::create ( cv::Size imageSize, std::vector< Rect > roiData, cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_PERF_LEVEL perfPreset = cv::cuda::NvidiaOpticalFlow_2_0::NV_OF_PERF_LEVEL_SLOW, cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_OUTPUT_VECTOR_GRID_SIZE outputGridSize = cv::cuda::NvidiaOpticalFlow_2_0::NV_OF_OUTPUT_VECTOR_GRID_SIZE_1, cv::cuda::NvidiaOpticalFlow_2_0::NVIDIA_OF_HINT_VECTOR_GRID_SIZE hintGridSize = cv::cuda::NvidiaOpticalFlow_2_0::NV_OF_HINT_VECTOR_GRID_SIZE_1, bool enableTemporalHints = false, bool enableExternalHints = false, bool enableCostBuffer = false, int gpuId = 0, Stream & inputStream = Stream::Null(), Stream & outputStream = Stream::Null() )

static

Instantiate NVIDIA Optical Flow with ROI Feature.

Parameters

imageSize	Size of input image in pixels.
roiData	Pointer to ROI data.
perfPreset	Optional parameter. Refer NV OF SDK documentation for details about presets. Defaults to NV_OF_PERF_LEVEL_SLOW.
outputGridSize	Optional parameter. Refer NV OF SDK documentation for details about output grid sizes. Defaults to NV_OF_OUTPUT_VECTOR_GRID_SIZE_1.
hintGridSize	Optional parameter. Refer NV OF SDK documentation for details about hint grid sizes. Defaults to NV_OF_HINT_VECTOR_GRID_SIZE_1.
enableTemporalHints	Optional parameter. Flag to enable temporal hints. When set to true, the hardware uses the flow vectors generated in previous call to calc() as internal hints for the current call to calc(). Useful when computing flow vectors between successive video frames. Defaults to false.
enableExternalHints	Optional Parameter. Flag to enable passing external hints buffer to calc(). Defaults to false.
enableCostBuffer	Optional Parameter. Flag to enable cost buffer output from calc(). Defaults to false.
gpuId	Optional parameter to select the GPU ID on which the optical flow should be computed. Useful in multi-GPU systems. Defaults to 0.
inputStream	Optical flow algorithm may optionally involve cuda preprocessing on the input buffers. The input cuda stream can be used to pipeline and synchronize the cuda preprocessing tasks with OF HW engine. If input stream is not set, the execute function will use default stream which is NULL stream;
outputStream	Optical flow algorithm may optionally involve cuda post processing on the output flow vectors. The output cuda stream can be used to pipeline and synchronize the cuda post processing tasks with OF HW engine. If output stream is not set, the execute function will use default stream which is NULL stream;

---

The documentation for this class was generated from the following file:

• opencv2/cudaoptflow.hpp