Package com.openinventor.imageviz.engines.edgedetection.gradient

Class SoGradientOperatorProcessing3d

  • All Implemented Interfaces:
    SafeDisposable
    public class SoGradientOperatorProcessing3d
extends SoImageVizEngine
    SoGradientOperatorProcessing3d engine provides different operators to extract the edges from a 3D image. For an introduction, see:

    • section Edge Detection
    • section Images Filters
    • Introduction to Gradient

    The SoGradientOperatorProcessing3d engine provides different operators to extract the edges from an image:

    • Canny-Deriche: It performs a recursive gradient computation to get the gradient in X, Y and Z directions. It is an FIR (finite impulse response) filter. To minimize the effect of noise, it smooths the image before computing the gradient. A smoothing scale parameter determines the smoothing intensity. If the value is large, noise will be reduced but edges will be less sharp and only the most significant edges will survive. It is important to select the right coefficient to lower the noise just enough without defocusing the edges. Then it gets the maximum of these images with a gradient magnitude operation. For color images it calculates the maximum of intensity or the euclidian mean.
    • Canny: It performs an approximation of to get the Canny Deriche in X and Y directions using a convolution kernel 7x5x5 for X, 5x7x5 for Y and 5x5x7 for Z. The result is nearly the same as with Canny Deriche but the processing is much faster.
    • Gaussian: It performs a convolution with the derivatives of a gaussian function along each image axis.
    • Sobel: It performs a convolution with the Sobel Kernel. This kernel is the 3D generalization of the Sobel kernel described in SoGradientOperatorProcessing2d
    • Prewitt: It performs a convolution with the Prewitt Kernel. This kernel is the 3D generalization of the Prewitt kernel described in SoGradientOperatorProcessing2d

    See Also:
    SoRadialGradientCenteredProcessing3d, SoMorphologicalGradientProcessing File format/default: GradientOperatorProcessing3d { inImage NULL gradientOperator CANNY_DERICHE gradientMode AMPLITUDE_MAX_OF_MAGS standardDeviation 60.0f } Library references: gradient3d