Stereo Block Matching

Detailed Description

The Stereo Block Matching Primitive.

This primitive computes a dense disparity map for given stereo pair. The rectified input is expected.

The primitive uses the following identifiers:

• NVX_KERNEL_STEREO_BLOCK_MATCHING for vxGetKernelByEnum function;
• "com.nvidia.nvx.stereo_block_matching" for vxGetKernelByName function.

Method

The Block Matching algorithm finds optimal disparity in 0..maxDisparity range. It is defined as argminimum (argument of the minimum) of sum of absolute differences over winSize X winSize block.

\begin{eqnarray} D(y, x) &=& {argmin}_d {SAD (L(y, x), R(y, x - d))} \\ SAD(y, x) &=& \sum_{k={-r}}^r {abs(L(y, x) - R(y, x))} \end{eqnarray}

where

\[ r = \frac{winSize - 1}{2} \]

See also

[4]

Functions
vx_node	nvxStereoBlockMatchingNode (vx_graph graph, vx_image left, vx_image right, vx_image disp, vx_uint32 winSize, vx_uint32 maxDisparity)
	[Graph] This primitive computes a dense disparity map for a given stereo pair. More...
vx_status	nvxuStereoBlockMatching (vx_context context, vx_image left, vx_image right, vx_image disp, vx_uint32 winSize, vx_uint32 maxDisparity)
	[Immediate] This primitive computes a dense disparity map for a given stereo pair. More...

Function Documentation

vx_node nvxStereoBlockMatchingNode	(	vx_graph	graph,
		vx_image	left,
		vx_image	right,
		vx_image	disp,
		vx_uint32	winSize,
		vx_uint32	maxDisparity
	)

[Graph] This primitive computes a dense disparity map for a given stereo pair.

Parameters

[in]	graph	Specifies the graph.
[in]	left	Specifies the left image. Only VX_DF_IMAGE_U8 format is supported.
[in]	right	Specifies the right image. It must have the same size and format as left.
[out]	disp	Specifies the output disparity. Only VX_DF_IMAGE_U8 format is supported. It must have the same size as left.
[in]	winSize	Specifies the average window size for sum of absolute differences (SAD). It must be an odd integer in range \( [3, 31] \).
[in]	maxDisparity	Specifies the maximum possible disparity that is considered. It must be a positive integer not greater than 256 and divisible by 8.

Returns

A valid node reference or an error object (use vxGetStatus).

See also

Stereo Block Matching

vx_status nvxuStereoBlockMatching	(	vx_context	context,
		vx_image	left,
		vx_image	right,
		vx_image	disp,
		vx_uint32	winSize,
		vx_uint32	maxDisparity
	)

[Immediate] This primitive computes a dense disparity map for a given stereo pair.

Parameters

[in]	context	Specifies the context.
[in]	left	Specifies the left image. Only VX_DF_IMAGE_U8 format is supported.
[in]	right	Specifies the right image. It must have the same size and format as left.
[out]	disp	Specifies the output disparity. Only VX_DF_IMAGE_U8 format is supported. It must have the same size as left.
[in]	winSize	Specifies the average window size for sum of absolute differences (SAD). It must be an odd integer in range \( [3, 31] \).
[in]	maxDisparity	Specifies the maximum possible disparity that is considered. It must be a positive integer not greater than 256 and divisible by 8.

Returns

A vx_status enumerator.

Return values

VX_SUCCESS	No errors.
VX_ERROR_INVALID_REFERENCE	Supplied parameters are not a valid references.
VX_ERROR_INVALID_PARAMETERS	Supplied parameters are not valid.
VX_ERROR_INVALID_SCOPE	Supplied parameters are virtual objects that cannot be used in immediate mode.
VX_FAILURE	Internal error in primitive implementation; check the log for detailed information. (Framework: Log).

See also

Stereo Block Matching