Object: Parameter

Detailed Description

Defines the Parameter Object interface.

An abstract input, output, or bidirectional data object passed to a computer vision function. This object contains the signature of that parameter's usage from the kernel description. This information includes:

• Signature Index - The numbered index of the parameter in the signature.
• Object Type - e.g., VX_TYPE_IMAGE or VX_TYPE_ARRAY or some other object type from The VX_TYPE Constants.
• Usage Model - e.g., VX_INPUT, VX_OUTPUT, or VX_BIDIRECTIONAL.
• Presence State - e.g., VX_PARAMETER_STATE_REQUIRED or VX_PARAMETER_STATE_OPTIONAL.

Modules
	Parameter direction enumeration
	An indication of how a kernel will treat the given parameter.
	The Parameter Attributes Constants
	The parameter attributes list.
	The parameter state type constants.

Typedefs
typedef struct _vx_parameter *	vx_parameter
	An opaque reference to a single parameter. More...

Functions
vx_parameter VX_API_CALL	vxGetKernelParameterByIndex (vx_kernel kernel, vx_uint32 index)
	Retrieves a vx_parameter from a vx_kernel [R00703]. More...
vx_parameter VX_API_CALL	vxGetParameterByIndex (vx_node node, vx_uint32 index)
	Retrieves a vx_parameter from a vx_node [R00805]. More...
vx_status VX_API_CALL	vxQueryParameter (vx_parameter parameter, vx_enum attribute, void *ptr, vx_size size)
	Allows the client to query a parameter to determine its meta-information [R00822]. More...
vx_status VX_API_CALL	vxReleaseParameter (vx_parameter *param)
	Releases a reference to a parameter object [R00810]. The object may not be garbage collected until its total reference count is zero. More...
vx_status VX_API_CALL	vxSetParameterByIndex (vx_node node, vx_uint32 index, vx_reference value)
	Sets the specified parameter data for a kernel on the node [R00813]. More...
vx_status VX_API_CALL	vxSetParameterByReference (vx_parameter parameter, vx_reference value)
	Associates a parameter reference and a data reference with a kernel on a node [R00818]. More...

Typedef Documentation

vx_parameter

typedef struct _vx_parameter* vx_parameter

An opaque reference to a single parameter.

See also

vxGetParameterByIndex

Definition at line 205 of file vx_types.h.

Function Documentation

vxGetKernelParameterByIndex()

vx_parameter VX_API_CALL vxGetKernelParameterByIndex	(	vx_kernel	kernel,
		vx_uint32	index
	)

Retrieves a vx_parameter from a vx_kernel [R00703].

Parameters

[in]	kernel	The reference to the kernel [R00704].
[in]	index	The index of the parameter [R00705].

Returns

A vx_parameter reference [R00706]. Any possible errors preventing a successful completion of the function should be checked using vxGetStatus [R00707].

vxGetParameterByIndex()

vx_parameter VX_API_CALL vxGetParameterByIndex	(	vx_node	node,
		vx_uint32	index
	)

Retrieves a vx_parameter from a vx_node [R00805].

Parameters

[in]	node	The node from which to extract the parameter [R00806].
[in]	index	The index of the parameter to which to get a reference [R00807].

Returns

A parameter reference vx_parameter [R00808]. Any possible errors preventing a successful completion of the function should be checked using vxGetStatus [R00809].

vxReleaseParameter()

vx_status VX_API_CALL vxReleaseParameter

(

vx_parameter *

param

)

Releases a reference to a parameter object [R00810]. The object may not be garbage collected until its total reference count is zero.

Parameters

[in]

param

The pointer to the parameter to release [R00811].

Postcondition

After returning from this function the reference is zeroed.

Returns

A The vx_status Constants value.

Return values

VX_SUCCESS	No errors; any other value indicates failure [R00812].
VX_ERROR_INVALID_REFERENCE	param is not a valid vx_parameter reference.

vxSetParameterByIndex()

vx_status VX_API_CALL vxSetParameterByIndex	(	vx_node	node,
		vx_uint32	index,
		vx_reference	value
	)

Sets the specified parameter data for a kernel on the node [R00813].

Parameters

[in]	node	The node that contains the kernel [R00814].
[in]	index	The index of the parameter desired [R00815].
[in]	value	The desired value of the parameter [R00816].

Note

A user may not provide a NULL value for a mandatory parameter of this API.

Returns

A The vx_status Constants value.

Return values

VX_SUCCESS	No errors; any other value indicates failure [R00817].
VX_ERROR_INVALID_REFERENCE	node is not a valid vx_node reference, or value is not a valid vx_reference reference.

See also

vxSetParameterByReference

vxSetParameterByReference()

vx_status VX_API_CALL vxSetParameterByReference	(	vx_parameter	parameter,
		vx_reference	value
	)

Associates a parameter reference and a data reference with a kernel on a node [R00818].

Parameters

[in]	parameter	The reference to the kernel parameter [R00819].
[in]	value	The value to associate with the kernel parameter [R00820].

Note

A user may not provide a NULL value for a mandatory parameter of this API.

Returns

A The vx_status Constants value.

Return values

VX_SUCCESS	No errors; any other value indicates failure [R00821].
VX_ERROR_INVALID_REFERENCE	parameter is not a valid vx_parameter reference, or value is not a valid vx_reference reference..

See also

vxGetParameterByIndex

vxQueryParameter()

vx_status VX_API_CALL vxQueryParameter	(	vx_parameter	parameter,
		vx_enum	attribute,
		void *	ptr,
		vx_size	size
	)

Allows the client to query a parameter to determine its meta-information [R00822].

Parameters

[in]	parameter	The reference to the parameter [R00823].
[in]	attribute	The attribute to query. Use a The Parameter Attributes Constants [R00824].
[out]	ptr	The location at which to store the resulting value [R00825].
[in]	size	The size in bytes of the container to which ptr points [R00826].

Returns

A The vx_status Constants value.

Return values

VX_SUCCESS	No errors; any other value indicates failure [R00827].
VX_ERROR_INVALID_REFERENCE	parameter is not a valid vx_parameter reference.