rcaiman (version 1.2.2)

expand_noncircular: Expand non-circular

Description

Expand a non-circular hemispherical photograph.

Usage

expand_noncircular(caim, z, zenith_colrow)

Value

An object of class SpatRaster that is the result of adding margins (NA pixels) to caim. The zenith point depicted in the picture should be in the center of the image or very close to it.

Arguments

caim

SpatRaster. The return of a call to read_caim() or read_caim_raw().

z

SpatRaster built with zenith_image().

zenith_colrow

Numeric vector of length two. Raster coordinates of the zenith. See calc_zenith_colrow().

See Also

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

Examples

if (FALSE) {

 # ====================================================================
 # Non-circular Fisheye images from a Smartphone with an Auxiliary Lens
 # (Also applicable to Non-circular images from DSLR cameras)
 # ====================================================================

 path <- system.file("external/APC_0581.jpg", package = "rcaiman")
 caim <- read_caim(path)
 z <- zenith_image(2132/2,  c(0.7836, 0.1512, -0.1558))
 a <- azimuth_image(z)
 zenith_colrow <- c(1063, 771)/2
 caim <- expand_noncircular(caim, z, zenith_colrow)
 plot(caim$Blue, col = seq(0,1,1/255) %>% grey())
 m <- !is.na(caim$Red) & !is.na(z)
 plot(m, add = TRUE, alpha = 0.3, legend = FALSE)


 # ============================
 # Restricted View Canopy Photo
 # ============================

 path <- system.file("external/APC_0020.jpg", package = "rcaiman")
 caim <- read_caim(path)
 plot(caim)
 caim <- normalize(caim)
 diameter <- calc_diameter(lens(), sqrt(nrow(caim)^2 + ncol(caim)^2)/2, 90)
 z <- zenith_image(diameter, lens())
 caim <- expand_noncircular(caim, z, c(ncol(caim)/2, nrow(caim)/2))
 m <- !is.na(caim$Red)
 a <- azimuth_image(z)
 caim[!m] <- 0
 z <- normalize(z, 0, 90) * 30.15 #60.3º diagonal FOV according to metadata
 plot(caim$Blue, col = seq(0,1,1/255) %>% grey())
 m <- !is.na(caim$Red) & !is.na(z)
 plot(m, add = TRUE, alpha = 0.3, legend = FALSE)
}