The parameter L is the length of the vessel segment to be processed, T is the position where the Gaussian curve trails will cut, and [kappa] represents the number of orientations in the directional filter
CT is a multiscale and directional decomposition of a signal using a combination of a modified Laplacian Pyramid (LP) and a Directional Filter
Bank (DFB).Efficient representations of signals require that coefficients of functions, which represent the Regions Of Interest (ROI) are sparse.
The texture of an image with strong directionality reflects the contours and directional edges of the image, and the directional filter
bank (DFB) of the NSST can effectively capture high-frequency content.
However, contourlet transform is limited in shift-invariance because of the downsampling process in the Laplacian pyramid and directional filter
bank, and this drawback may cause pseudo-Gibbs phenomena around singularities, which reduces the local information and weakens the features of the directional selection.
The traditional bi- directional filter
performs weighted averaging in the neighborhood.
Then these point discontinuities are transformed in to a linear structure with the help of Directional Filter
Bank (DFB) .
Based on the intrinsic characteristics of the ridge pattern in fingerprint images, Kamei  proposes a filter designed in the Fourier domain, having two distinct components, a frequency filter corresponding to ridge frequency and a directional filter
corresponding to ridge orientation.
A directional filter
could allow the sun's rays, which come in at a predictable angle, to pass through but prevent the escape of heat in the form of infrared light.
When processing raw bayer-filtered video files, you need a stacking program that gives you options to utilize the newer debayering algorithms, specifically High Quality Linear and Directional Filter
. Algorithms such as these are much more effective because they examine both larger blocks (8*8 and larger), rows, and columns of pixels to derive a more accurate trichromatic representation.
As shown in Figure 4, the SFL-CT is constructed as a combination of the SFL-FB and the directional filter
NSCT removes the subsampling sections in two-level implementations of Contourlet transform and is made up of Nonsubsampled Pyramid (NSP) and Nonsubsampled Directional Filter
Bank (NSDFB) (See Figure 3).
The contourlet transform is a multidirectional and multiscale transform which is constructed by combining Laplacian pyramid (LP) with directional filter
bank proposed in .