zenith_image: Build Zenith image

In rcaiman: CAnopy IMage ANalysis

Build Zenith image

Description

Build a single layer-image with zenith angle values, assuming upwards-looking hemispherical photography with the optical axis vertically aligned.

Usage

zenith_image(diameter, lens_coef)

Arguments

diameter	Numeric vector of length one. Diameter in pixels expressed as an even integer. The latter is to simplify calculations by having the zenith point located between pixels. Snapping the zenith point between pixels does not affect accuracy because half-pixel is less than the uncertainty in localizing the circle within the picture.
lens_coef	Numeric vector. Polynomial coefficients of the lens projection function. See calibrate_lens().

Value

An object of class SpatRaster of zenith angles in degrees, showing a complete hemispherical view with the zenith on the center.

See Also

Other Lens Functions: azimuth_image(), calc_diameter(), calc_relative_radius(), calc_zenith_colrow(), calibrate_lens(), crosscalibrate_lens(), expand_noncircular(), extract_radiometry(), fisheye_to_equidistant(), fisheye_to_pano(), lens(), test_lens_coef()

Examples

z <- zenith_image(600, lens("Nikon_FCE9"))
plot(z)

rcaiman documentation built on Nov. 15, 2023, 1:08 a.m.