binarize_fisheye        Compute the threshold of a single-channel
                        fisheye image, and return a binary fisheye
                        image of canopy (0) and gap (1) pixels
camera_fisheye          Provide circular mask parameters from known
                        camera+fisheye lens models
canopy_fisheye          Calculate canopy attributes from angular gap
                        fraction data derived from fisheye images
gapfrac_fisheye         Derive angular gap fraction from a classified
                        fisheye image
import_fisheye          Import a fisheye image as a single channel
                        raster, and apply a circular mask
zonal_mask              Divide a raster image into four stacks which
                        are used as masks.
