Generate a Gabor filter kernel

Returns a numeric matrix containing Gabor filter coefficients, suitable for use as kernel in $filter2D().

Usage

get_gabor_kernel(
  ksize,
  sigma,
  theta,
  lambda,
  gamma,
  psi = pi/2,
  kdepth = "CV_64F"
)

Arguments

ksize

Length-2 integer vector c(width, height). Both must be positive odd integers.

sigma

Single positive numeric. Standard deviation of the Gaussian envelope.

theta

Single numeric. Orientation of the filter normal in degrees (converted to radians internally).

lambda

Single positive numeric. Wavelength of the sinusoidal component, in pixels.

gamma

Single positive numeric. Spatial aspect ratio. Values less than 1 produce elongated filters; 1 gives a circular envelope.

psi

Single numeric. Phase offset in radians. Default pi / 2.

kdepth

Character. Precision of the returned kernel matrix: "CV_32F" (single-precision float) or "CV_64F" (double-precision, default).

Value

A numeric matrix of dimensions height x width.

Examples

k <- get_gabor_kernel(c(9L, 9L), sigma = 2, theta = 0, lambda = 5, gamma = 0.5)
dim(k)
#> [1] 9 9