R/generateGabor.R

In rcicr: Reverse-Correlation Image-Classification Toolbox

#' Generate single gabor patch
#'
#' @export
#' @param img_size Integer specifying size of gabor patch in number of pixels.
#' @param cycles Integer specifying number of cycles the sinusoid should span.
#' @param angle Value specifying the angle (rotation) of the sinusoid.
#' @param phase Value specifying phase of sinusoid.
#' @param sigma Value specifying the standard deviation, in pixels, of the
#'   Gaussian mask applied on top of the sinusoid.
#' @param contrast Value between -1.0 and 1.0 specifying contrast of sinusoid.
#' @return The gabor patch image with size \code{img_size}.
#' @examples
#' generateGabor(512, 2, 90, pi/2, 25, 1.0)
generateGabor <- function(img_size, cycles, angle, phase, sigma, contrast) {

  s <- generateSinusoid(img_size, cycles, angle, phase, contrast)
  x0 <- scales::rescale(1:img_size, to = c(-.5, .5))
  gauss <- matlab::meshgrid(x0, x0)
  gauss_mask <- exp(-(((gauss$x^2) + (gauss$y^2)) / (2 * (sigma / img_size)^2)))
  return(gauss_mask * s)

}