Entropy-based segmentation of a SAR/PolSAR image

Convenience wrapper that computes the entropy map(s) with entropy_map() and segments them with EntropySegmenter.

Usage

segment_sar(
  image,
  k = 2,
  model = c("wishart", "g0p", "gamma", "g0i", "ggamma"),
  window = 7,
  L = NULL,
  channels = NULL,
  method = c("em", "sem"),
  ...
)

Arguments

image: A SARImage or an array accepted by SARImage$new().
k: Number of classes.
model: One of "gamma", "g0i", "ggamma" (intensity models, applied to each channel) or "wishart", "g0p" (matrix models, for PolSAR images).
window: Odd side of the moving window.
L: Known number of looks. If NULL (default) it is estimated in every window.
channels: Channels used by intensity models (default: all).
method: "em" or "sem".
...: Passed to EntropySegmenter$new().

Value

A fitted EntropySegmenter; the labels are available with $label_map().

Examples

set.seed(1)
seg <- segment_sar(SanFrancisco150, k = 3, model = "gamma", window = 7, L = 4)
table(seg$label_map(), SanFrancisco150_gt)
#>    SanFrancisco150_gt
#>        1    2    3
#>   1 5845   72    0
#>   2   81 5904  350
#>   3    1  457 9790