Detailed Description

Defines the Kernel Object and Interface.

A Kernel in OpenVX is the abstract representation of an computer vision function, such as a “Sobel Gradient” or “Lucas Kanade Feature Tracking”. A vision function may implement many similar or identical features from other functions, but it is still considered a single unique kernel as long as it is named by the same string and enumeration and conforms to the results specified by OpenVX. Kernels are similar to function signatures in this regard.

In each of the cases, a client of OpenVX could request the kernels in nearly the same manner. There are two main approaches, which depend on the method a client calls to get the kernel reference. The first uses enumerations.

vx_kernel kernel = vxGetKernelByEnum(context, VX_KERNEL_SOBEL_3x3);

vx_node node = vxCreateGenericNode(graph, kernel);

The second method depends on using strings to get the kernel reference.

vx_kernel kernel = vxGetKernelByName(context, "org.khronos.openvx.sobel3x3");

vx_node node = vxCreateGenericNode(graph, kernel);

Data Structures
struct	vx_kernel_info_t
	The Kernel Information Structure. This is returned by the Context to indicate which kernels are available in the OpenVX implementation. More...

Macros
#define	VX_MAX_KERNEL_NAME (256)
	Defines the maximum string length of a kernel name to be added to OpenVX.

Typedefs
typedef struct _vx_kernel *	vx_kernel
	An opaque reference to the descriptor of a kernel. More...

Enumerations
enum	vx_kernel_attribute_e { VX_KERNEL_ATTRIBUTE_PARAMETERS = ((( VX_ID_KHRONOS ) << 20) \| ( VX_TYPE_KERNEL << 8)) + 0x0, VX_KERNEL_ATTRIBUTE_NAME = ((( VX_ID_KHRONOS ) << 20) \| ( VX_TYPE_KERNEL << 8)) + 0x1, VX_KERNEL_ATTRIBUTE_ENUM = ((( VX_ID_KHRONOS ) << 20) \| ( VX_TYPE_KERNEL << 8)) + 0x2, VX_KERNEL_ATTRIBUTE_LOCAL_DATA_SIZE = ((( VX_ID_KHRONOS ) << 20) \| ( VX_TYPE_KERNEL << 8)) + 0x3, VX_KERNEL_ATTRIBUTE_LOCAL_DATA_PTR = ((( VX_ID_KHRONOS ) << 20) \| ( VX_TYPE_KERNEL << 8)) + 0x4 }
	The kernel attributes list. More...

enum	vx_kernel_e { VX_KERNEL_INVALID = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x0, VX_KERNEL_COLOR_CONVERT = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x1, VX_KERNEL_CHANNEL_EXTRACT = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x2, VX_KERNEL_CHANNEL_COMBINE = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x3, VX_KERNEL_SOBEL_3x3 = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x4, VX_KERNEL_MAGNITUDE = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x5, VX_KERNEL_PHASE = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x6, VX_KERNEL_SCALE_IMAGE = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x7, VX_KERNEL_TABLE_LOOKUP = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x8, VX_KERNEL_HISTOGRAM = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x9, VX_KERNEL_EQUALIZE_HISTOGRAM = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0xA, VX_KERNEL_ABSDIFF = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0xB, VX_KERNEL_MEAN_STDDEV = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0xC, VX_KERNEL_THRESHOLD = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0xD, VX_KERNEL_INTEGRAL_IMAGE = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0xE, VX_KERNEL_DILATE_3x3 = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0xF, VX_KERNEL_ERODE_3x3 = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x10, VX_KERNEL_MEDIAN_3x3 = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x11, VX_KERNEL_BOX_3x3 = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x12, VX_KERNEL_GAUSSIAN_3x3 = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x13, VX_KERNEL_CUSTOM_CONVOLUTION = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x14, VX_KERNEL_GAUSSIAN_PYRAMID = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x15, VX_KERNEL_ACCUMULATE = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x16, VX_KERNEL_ACCUMULATE_WEIGHTED = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x17, VX_KERNEL_ACCUMULATE_SQUARE = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x18, VX_KERNEL_MINMAXLOC = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x19, VX_KERNEL_CONVERTDEPTH = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x1A, VX_KERNEL_CANNY_EDGE_DETECTOR = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x1B, VX_KERNEL_AND = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x1C, VX_KERNEL_OR = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x1D, VX_KERNEL_XOR = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x1E, VX_KERNEL_NOT = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x1F, VX_KERNEL_MULTIPLY = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x20, VX_KERNEL_ADD = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x21, VX_KERNEL_SUBTRACT = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x22, VX_KERNEL_WARP_AFFINE = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x23, VX_KERNEL_WARP_PERSPECTIVE = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x24, VX_KERNEL_HARRIS_CORNERS = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x25, VX_KERNEL_FAST_CORNERS = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x26, VX_KERNEL_OPTICAL_FLOW_PYR_LK = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x27, VX_KERNEL_REMAP = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x28, VX_KERNEL_HALFSCALE_GAUSSIAN = VX_KERNEL_BASE(VX_ID_KHRONOS, VX_LIBRARY_KHR_BASE) + 0x29, VX_KERNEL_MAX_1_0 }
	The standard list of available vision kernels. More...

Functions
vx_kernel	vxGetKernelByEnum (vx_context context, vx_enum kernel)
	Obtains a reference to the kernel using the `vx_kernel_e` enumeration. More...

vx_kernel	vxGetKernelByName (vx_context context, vx_char *name)
	Obtains a reference to a kernel using a string to specify the name. More...

vx_status	vxQueryKernel (vx_kernel kernel, vx_enum attribute, void *ptr, vx_size size)
	This allows the client to query the kernel to get information about the number of parameters, enum values, etc. More...

vx_status	vxReleaseKernel (vx_kernel *kernel)
	Release the reference to the kernel. The object may not be garbage collected until its total reference count is zero. More...

Data Structure Documentation

struct vx_kernel_info_t

The Kernel Information Structure. This is returned by the Context to indicate which kernels are available in the OpenVX implementation.

Definition at line 1311 of file vx_types.h.

Data Fields
vx_enum	enumeration	The kernel enumeration value from `vx_kernel_e` (or an extension thereof). See also vxGetKernelByEnum
vx_char	name[VX_MAX_KERNEL_NAME]	The kernel name in dotted hierarchical format. e.g. "org.khronos.openvx.sobel3x3". See also vxGetKernelByName

Typedef Documentation

typedef struct _vx_kernel* vx_kernel

An opaque reference to the descriptor of a kernel.

See also: vxGetKernelByName; vxGetKernelByEnum

Definition at line 152 of file vx_types.h.

Enumeration Type Documentation

enum vx_kernel_e

The standard list of available vision kernels.

Each kernel listed here can be used with the vxGetKernelByEnum call. When programming the parameters, use

VX_INPUT for [in]
VX_OUTPUT for [out]
VX_BIDIRECTIONAL for [in,out]

When programming the parameters, use

VX_TYPE_IMAGE for a vx_image in the size field of vxGetParameterByIndex or vxSetParameterByIndex *
VX_TYPE_ARRAY for a vx_array in the size field of vxGetParameterByIndex or vxSetParameterByIndex *
or other appropriate types in vx_type_e.

Enumerator
VX_KERNEL_INVALID	The invalid kernel is used to for conformance failure in relation to some kernel operation (Get/Release). If the kernel is executed it shall always return an error. The kernel has no parameters. To address by name use "org.khronos.openvx.invalid".
VX_KERNEL_COLOR_CONVERT	The Color Space conversion kernel. The conversions are based on the `vx_df_image_e` code in the images. See also Color Convert
VX_KERNEL_CHANNEL_EXTRACT	The Generic Channel Extraction Kernel. This kernel can remove individual color channels from an interleaved or semi-planar, planar, sub-sampled planar image. A client could extract a red channel from an interleaved RGB image or do a Luma extract from a YUV format. See also Channel Extract
VX_KERNEL_CHANNEL_COMBINE	The Generic Channel Combine Kernel. This kernel combine multiple individual planes into a single multiplanar image of the type specified in the output image. See also Channel Combine
VX_KERNEL_SOBEL_3x3	The Sobel 3x3 Filter Kernel. See also Sobel 3x3
VX_KERNEL_MAGNITUDE	The Magnitude Kernel. This kernel produces a magnitude plane from two input gradients. See also Magnitude
VX_KERNEL_PHASE	The Phase Kernel. This kernel produces a phase plane from two input gradients. See also Phase
VX_KERNEL_SCALE_IMAGE	The Scale Image Kernel. This kernel provides resizing of an input image to an output image. The scaling factor is determined but the relative sizes of the input and output. See also Scale Image
VX_KERNEL_TABLE_LOOKUP	The Table Lookup kernel. See also TableLookup
VX_KERNEL_HISTOGRAM	The Histogram Kernel. See also Histogram
VX_KERNEL_EQUALIZE_HISTOGRAM	The Histogram Equalization Kernel. See also Equalize Histogram
VX_KERNEL_ABSDIFF	The Absolute Difference Kernel. See also Absolute Difference
VX_KERNEL_MEAN_STDDEV	The Mean and Standard Deviation Kernel. See also Mean and Standard Deviation
VX_KERNEL_THRESHOLD	The Threshold Kernel. See also Thresholding
VX_KERNEL_INTEGRAL_IMAGE	The Integral Image Kernel. See also Integral Image
VX_KERNEL_DILATE_3x3	The dilate kernel. See also Dilate Image
VX_KERNEL_ERODE_3x3	The erode kernel. See also Dilate Image
VX_KERNEL_MEDIAN_3x3	The median image filter. See also Median Filter
VX_KERNEL_BOX_3x3	The box filter kernel. See also Box Filter
VX_KERNEL_GAUSSIAN_3x3	The gaussian filter kernel. See also Gaussian Filter
VX_KERNEL_CUSTOM_CONVOLUTION	The custom convolution kernel. See also Custom Convolution
VX_KERNEL_GAUSSIAN_PYRAMID	The gaussian image pyramid kernel. See also Gaussian Image Pyramid
VX_KERNEL_ACCUMULATE	The accumulation kernel. See also Accumulate
VX_KERNEL_ACCUMULATE_WEIGHTED	The weigthed accumulation kernel. See also Accumulate Weighted
VX_KERNEL_ACCUMULATE_SQUARE	The squared accumulation kernel. See also Accumulate Squared
VX_KERNEL_MINMAXLOC	The min and max location kernel. See also Min, Max Location
VX_KERNEL_CONVERTDEPTH	The bit-depth conversion kernel. See also Convert Bit depth
VX_KERNEL_CANNY_EDGE_DETECTOR	The Canny Edge Detector. See also Canny Edge Detector
VX_KERNEL_AND	The Bitwise And Kernel. See also Bitwise AND
VX_KERNEL_OR	The Bitwise Inclusive Or Kernel. See also Bitwise INCLUSIVE OR
VX_KERNEL_XOR	The Bitwise Exclusive Or Kernel. See also Bitwise EXCLUSIVE OR
VX_KERNEL_NOT	The Bitwise Not Kernel. See also Bitwise NOT
VX_KERNEL_MULTIPLY	The Pixelwise Multiplication Kernel. See also Pixel-wise Multiplication
VX_KERNEL_ADD	The Addition Kernel. See also Arithmetic Addition
VX_KERNEL_SUBTRACT	The Subtraction Kernel. See also Arithmetic Subtraction
VX_KERNEL_WARP_AFFINE	The Warp Affine Kernel. See also Warp Affine
VX_KERNEL_WARP_PERSPECTIVE	The Warp Perspective Kernel. See also Warp Perspective
VX_KERNEL_HARRIS_CORNERS	The Harris Corners Kernel. See also Harris Corners
VX_KERNEL_FAST_CORNERS	The FAST Corners Kernel. See also Fast Corners
VX_KERNEL_OPTICAL_FLOW_PYR_LK	The Optical Flow Pyramid (LK) Kernel. See also Optical Flow Pyramid (LK)
VX_KERNEL_REMAP	The Remap Kernel. See also Remap
VX_KERNEL_HALFSCALE_GAUSSIAN	The Half Scale Gaussian Kernel. See also Scale Image

Definition at line 56 of file vx_kernels.h.

enum vx_kernel_attribute_e

The kernel attributes list.

Enumerator
VX_KERNEL_ATTRIBUTE_PARAMETERS	Queries a kernel for the number of parameters the kernel supports. Use a `vx_uint32` parameter.
VX_KERNEL_ATTRIBUTE_NAME	Queries the name of the kernel. Not settable. Use a `vx_char`[`VX_MAX_KERNEL_NAME`] array (not a `vx_array`).
VX_KERNEL_ATTRIBUTE_ENUM	Queries the enum of the kernel. Not settable. Use a `vx_enum` parameter.
VX_KERNEL_ATTRIBUTE_LOCAL_DATA_SIZE	The local data area allocated with each kernel when it becomes a node. Use a `vx_size` parameter. Note If not set it will default to zero.
VX_KERNEL_ATTRIBUTE_LOCAL_DATA_PTR	The local data pointer allocated with each kernel when it becomes a node. Use a void pointer parameter. Use a `vx_size` parameter.

Definition at line 700 of file vx_types.h.

Function Documentation

vx_kernel vxGetKernelByName	(	vx_context	context,
		vx_char *	name
	)

Obtains a reference to a kernel using a string to specify the name.

Parameters

[in]	context	The reference to the implementation context.
[in]	name	The string of the name of the kernel to get.

Returns: A kernel reference or zero if an error occurred.

Return values

0	The kernel name is not found in the context.

Precondition: vxLoadKernels if the kernel is not provided by the OpenVX implementation.

Note: User Kernels should follow a "dotted" heirarchical syntax. For example: "com.company.example.xyz".

vx_kernel vxGetKernelByEnum	(	vx_context	context,
		vx_enum	kernel
	)

Obtains a reference to the kernel using the vx_kernel_e enumeration.

Enum values above the standard set are assumed to apply to loaded libraries.

Parameters

[in]	context	The reference to the implementation context.
[in]	kernel	A value from `vx_kernel_e` or a vendor or client-defined value.

Returns: A vx_kernel.

Return values

0	The kernel enumeration is not found in the context.

Precondition: vxLoadKernels if the kernel is not provided by the OpenVX implementation.

vx_status vxQueryKernel	(	vx_kernel	kernel,
		vx_enum	attribute,
		void *	ptr,
		vx_size	size
	)

This allows the client to query the kernel to get information about the number of parameters, enum values, etc.

Parameters

[in]	kernel	The kernel reference to query.
[in]	attribute	The attribute to query. Use a `vx_kernel_attribute_e`.
[out]	ptr	The pointer to the location at which to store the resulting value.
[in]	size	The size of the container to which ptr points.

Returns: A vx_status_e enumeration.

Return values

VX_SUCCESS	No errors.
VX_ERROR_INVALID_REFERENCE	If the kernel is not a `vx_kernel`.
VX_ERROR_INVALID_PARAMETERS	If any of the other parameters are incorrect.
VX_ERROR_NOT_SUPPORTED	If the attribute value is not supported in this implementation.

vx_status vxReleaseKernel ( vx_kernel * kernel )

Release the reference to the kernel. The object may not be garbage collected until its total reference count is zero.

Parameters

[in] kernel The pointer to the kernel reference to release.

Postcondition: After returning from this function the reference is zeroed.

Returns: A vx_status_e enumeration.

Return values

VX_SUCCESS	No errors.
VX_ERROR_INVALID_REFERENCE	If graph is not a `vx_graph`.

Detailed Description

Data Structures

Macros

Typedefs

Enumerations

Functions

Data Structure Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation