VisionWorks Toolkit Reference

April 8, 2016 | 1.4 Release

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Detailed Description

The Scharr 3x3 Image Filter Kernel.

This function takes an image and produces two planes that are X and Y derivative estimates of the input image after application of Scharr 3x3 operators.

The Scharr operators used in estimating the X and Y derivatives \( G_x, G_y \) respectively are defined as follows:

\[ \mathbf{G}_x=\begin{vmatrix} -3 & 0 & +3 \\ -10 & 0 & +10 \\ -3 & 0 & +3 \end{vmatrix} , \mathbf{G}_y=\begin{vmatrix} -3 & -10 & -3 \\ 0 & 0 & 0 \\ +3 & +10 & +3 \end{vmatrix} \]

The primitive uses the following identifiers:

Functions

vx_node nvxScharr3x3Node (vx_graph graph, vx_image input, vx_image grad_x, vx_image grad_y)
 [Graph] Applies Scharr 3 x 3 operator. More...
 
vx_status nvxuScharr3x3 (vx_context context, vx_image input, vx_image grad_x, vx_image grad_y)
 [Immediate] Applies Scharr 3 x 3 operator. More...
 

Function Documentation

vx_node nvxScharr3x3Node ( vx_graph  graph,
vx_image  input,
vx_image  grad_x,
vx_image  grad_y 
)

[Graph] Applies Scharr 3 x 3 operator.

Parameters
[in]graphSpecifies the graph.
[in]inputSpecifies the input image. Only VX_DF_IMAGE_U8 format is supported.
[out]grad_x[optional] Specifies the output gradient in the x direction. Only VX_DF_IMAGE_S16 format is supported.
[out]grad_y[optional] Specifies the output gradient in the y direction. Only VX_DF_IMAGE_S16 format is supported.
Note
At least one output parameter (grad_x or grad_y) must be provided.
Returns
A valid node reference or an error object (use vxGetStatus).
See also
Scharr3x3
vx_status nvxuScharr3x3 ( vx_context  context,
vx_image  input,
vx_image  grad_x,
vx_image  grad_y 
)

[Immediate] Applies Scharr 3 x 3 operator.

Parameters
[in]contextSpecifies the context.
[in]inputSpecifies the input image. Only VX_DF_IMAGE_U8 format is supported.
[out]grad_x[optional] Specifies the output gradient in the x direction. Only VX_DF_IMAGE_S16 format is supported.
[out]grad_y[optional] Specifies the output gradient in the y direction. Only VX_DF_IMAGE_S16 format is supported.
Note
At least one output parameter (grad_x or grad_y) must be provided.
Returns
A vx_status enumerator.
Return values
VX_SUCCESSNo errors.
VX_ERROR_INVALID_REFERENCESupplied parameters are not a valid references.
VX_ERROR_INVALID_PARAMETERSSupplied parameters are not valid.
VX_ERROR_INVALID_SCOPESupplied parameters are virtual objects, that cannot be used in immediate mode.
VX_FAILUREInternal error in primitive implementation, check log for detailed information (Framework: Log).
See also
Scharr3x3