public class DefaultCreateKernel2ndDerivBiGauss<T extends ComplexType<T>>
extends AbstractBinaryFunctionOp<double[],Integer,RandomAccessibleInterval<T>>
implements Ops.Create.Kernel2ndDerivBiGauss

Creates 2nd derivative of an isotropic BiGauss kernel with the pair of sigmas specification.

The BiGauss kernel is a composition of two standard Gauss kernels. If we were to assume 1D kernel centered at zero (0), an inner kernel of the BiGauss, with its shape given with sigmas[0], would span from -sigmas[0] till +sigmas[0]; outer kernel, with its shape given with sigmas[1], surrounds the inner, e.g. for the positive side, from sigmas[0] till sigmas[0]+2*sigmas[1] and its center having at sigmas[0]-sigmas[1]. That is, the inner Gauss exist up to its inflection points from which the filter takes shape of the outer Gauss. Both kernels are, however, appropriately scaled and shifted to obtain a smooth BiGauss kernel.

Note that the kernel is always isotropic. The second parameter gives dimensionality of the created kernel.

All values are in units of pixels.

Literature:C. Xiao, M. Staring, Y. Wang, D.P. Shamonin, B.C. Stoel. Multiscale Bi-Gaussian Filter for Adjacent Curvilinear Structures Detection with Application to Vasculature Images. IEEE TMI, vol. 22, no. 1, 2013.