R/surfaceCluster.r

In DRIP: Discontinuous Regression and Image Processing

# This is R source code for function 'surfaceCluster', in the
# R package "DRIP".
# Date: September 05, 2017
# Creator: Yicheng Kang

surfaceCluster = function(image, bandwidth, sig.level, sigma, phi0, mean_std_abs, cw=3, 
  blur = FALSE, plot = FALSE){
  if (!is.matrix(image))
    stop("image data must be a matrix")
  else n1 = dim(image)[1]
       n2 = dim(image)[2]
  if (n1 != n2)
    stop("image data must be a square matrix")
  if (!is.numeric(bandwidth))
    stop("bandwidth must be numeric")
  if (length(bandwidth) > 1) {
    stop('bandwidth must be a positive integer')
  }
  if (n1 + 2 * bandwidth + 2 > 600)
    stop("some choice of bandwidth or the resolution of the
image is too large")
  if (!is.numeric(sig.level) | abs(sig.level - 0.5) > 0.5)
    { stop('sig.level must be a number between 0 and 1') }
  n1 = dim(image)[1]
  z = matrix(as.double(image), ncol = n1)
  zq = as.double(qnorm(sig.level))
  if (missing(sigma) | missing(phi0) | missing(mean_std_abs)) {
      jp.llk = JPLLK_surface(z, 2:7)
      fitted = jp.llk$fitted
      resid = jp.llk$resid
      sigma = as.double(jp.llk$sigma)
      std_resid = resid / sigma
      phi0 = as.double(density(x=std_resid, bw=1.06*n1^(-2/5), kernel="gaussian", n=4, from=-1, to=2)$y[2])
      mean_std_abs = as.double(mean(abs(std_resid)))
  }
  k = as.integer(bandwidth)
  cw = as.integer(cw)
  if (blur == FALSE) {
    out = .Fortran('cluster_cwm_denoise', n = as.integer(n1 - 1),
      obsImg = z, k = k, zq = zq, sigma=sigma, phi0=phi0, mean_std_abs=mean_std_abs, cw=cw, estImg = z)
  }
  else {
      out = .Fortran('cluster_cwm_deblur', n = as.integer(n1 - 1), obsImg = z, k = k,
                     zq = zq, sigma=sigma, phi0=phi0, mean_std_abs=mean_std_abs, cw=cw, estImg = z)
  }
  if (plot == FALSE) {
    return(list(estImg = out$estImg, sigma = sigma, phi0=phi0, mean_std_abs=mean_std_abs))
  }
  else { image(out$estImg, col = gray((0:255)/255))
         return(list(estImg = out$estImg, sigma = sigma, phi0=phi0, mean_std_abs=mean_std_abs))
       }
}