vtkFiniteDifferenceGradientEstimator - Use finite differences to estimate gradient.
Super Class: vtkEncodedGradientEstimator
Description:
vtkFiniteDifferenceGradientEstimator is a concrete subclass of vtkEncodedGradientEstimator that uses a central differences technique to estimate the gradient. The gradient at some sample location (x,y,z) would be estimated by: nx = (f(x-dx,y,z) - f(x+dx,y,z)) / 2*dx; ny = (f(x,y-dy,z) - f(x,y+dy,z)) / 2*dy; nz = (f(x,y,z-dz) - f(x,y,z+dz)) / 2*dz; This value is normalized to determine a unit direction vector and a magnitude. The normal is computed in voxel space, and dx = dy = dz = SampleSpacingInVoxels. A scaling factor is applied to convert this normal from voxel space to world coordinates.
See Also:
Methods:
| void vtkFiniteDifferenceGradientEstimator () |
| void vtkFiniteDifferenceGradientEstimator () |
| const char *GetClassName () |
| void PrintSelf (unknown & ,vtkIndent ) |
| static vtkFiniteDifferenceGradientEstimator *New () |
| void SetSampleSpacingInVoxels (int ) |
| int GetSampleSpacingInVoxels () |
| void UpdateNormals () |
Detailed Method Descriptions:
| static vtkFiniteDifferenceGradientEstimator *New () |
| void SetSampleSpacingInVoxels (int ) |
| int GetSampleSpacingInVoxels () |
| void UpdateNormals () |