azimuth_image: Build azimuth image

In rcaiman: CAnopy IMage ANalysis

Build azimuth image

Description

Build a single-layer image with azimuth angles as pixel values, assuming upwards-looking hemispherical photography with the optical axis vertically aligned.

Usage

azimuth_image(z, orientation = 0)

Arguments

z	SpatRaster built with zenith_image().
orientation	Azimuth angle (degrees) at which the top of the image was pointing at the moment of taking the picture. This design decision was made because the usual field protocol is recording the angle at which the top of the camera points.

Value

An object of class SpatRaster with azimuth angles in degrees. If the orientation argument is zero, North (0º) is pointing up as in maps, but East (90º) and West (270º) are flipped regarding to maps. To understand why, take two flash-card size pieces of paper; put one on a table in front of you and draw on it a compass rose; take the other and hold it with your arms extended over your head and, following the directions of the compass rose in front of you, draw another one in the paper side that is facing down—it will be an awkward position, like if you were taking an upward-looking photo with a mobile device while looking at the screen—; finally, put it down and compare both compass roses.

See Also

Other Lens Functions: 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(), zenith_image()

Examples

z <- zenith_image(600, lens("Nikon_FCE9"))
a <- azimuth_image(z)
plot(a)
## Not run: 
a <- azimuth_image(z, 45)
plot(a)

## End(Not run)

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