conventional_lens_image: Generate conventional-lens-like image

In rcaiman: CAnopy IMage ANalysis

Generate conventional-lens-like image

Description

Create an RGB image that resembles a photo taken with a conventional lens, using a small patch from the example hemispherical image.

Usage

conventional_lens_image()

Details

This is a fixed crop and reorientation of read_caim(). It does not perform any re-projection. Intended for documentating functions.

The following code was used to define the region:

caim <- read_caim()
r <- caim$Blue
z <- zenith_image(ncol(caim), lens())
a <- azimuth_image(z)

m <- rast(z)
m[] <- calc_spherical_distance(
  z[] * pi / 180,
  a[] * pi / 180,
  1,# hinge-angle
  90 * pi / 180
)
m <- !binarize_with_thr(m, 30 * pi / 180)
m[is.na(z)] <- 0
m

x11()
plot(m * caim$Blue)
za <- click(c(z, a))
za
row_col <- row_col_from_zenith_azimuth(z, a, za[,1], za[,2])
plot(caim$Blue)
points(row_col$col, nrow(caim) - row_col$row, col = 2, pch = 10)
mn_y <- min(nrow(caim) -row_col$row)
mx_y <- max(nrow(caim) -row_col$row)
mn_x <- min(row_col$col)
mx_x <- max(row_col$col)
r <- terra::crop(caim$Blue, terra::ext(mn_x, mx_x, mn_y, mx_y))
plot(r)

Value

Three-layer terra::SpatRaster with bands in RGB order.

See Also

read_caim()

Examples

conventional_lens_image()

rcaiman documentation built on Sept. 9, 2025, 5:42 p.m.