zenith_image

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

Classify hemispherical
photographs of the plant canopy with algorithms specially developed for
such a task and well documented in
Díaz and Lencinas (2015) <doi:10.1109/lgrs.2015.2425931> and
Díaz and Lencinas (2018) <doi:10.1139/cjfr-2018-0006>. It supports
non-circular hemispherical photography, such as those acquired with
15mm lenses or with auxiliary fish-eye lenses attached to mobile devices.
For smartphone-based hemispherical photography see
Díaz (2023) <doi:10.1111/2041-210x.14059>. Most of the functions also
support restricted view photography.

Gast<c3><b3>n Mauro D<c3><ad>az

rcaiman

CAnopy IMage ANalysis

Gastón Mauro Díaz

zenith_image function

<dl><dt>diameter</dt>
<dd>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.</dd>
<dt>lens_coef</dt>
<dd>Numeric vector. Polynomial coefficients of the lens
projection function. See <code>calibrate_lens()</code>.</dd></dl>

Arguments

Build Zenith image — zenith_image

<dl>

<dt>diameter</dt>
<dd>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.</dd>


<dt>lens_coef</dt>
<dd>Numeric vector. Polynomial coefficients of the lens
projection function. See <code>calibrate_lens()</code>.</dd>

</dl>

zenith_image: Build Zenith image

Description

Usage

Value

Arguments

See Also

Examples