expand_noncircular: Expand non-circular

In rcaiman: CAnopy IMage ANalysis

Expand non-circular

Description

Expand a non-circular hemispherical photograph.

Usage

expand_noncircular(caim, z, zenith_colrow)

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().

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.

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

## Not run: 

 # ====================================================================
 # 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)

## End(Not run)

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