Visualize true-color raster imagery — visualize_true_color

Reads a multi-band raster, converts the red, green, and blue bands to normalized RGB values, and creates a ggplot2 tile plot of the true-color composite. Optionally overlays point locations. Automatically normalizes image brightness to the global average (computed at app startup) for legibility, then applies the user brightness slider (0-10, default 5) as a multiplier.

Usage

visualize_true_color_imagery(
  file,
  df_coordinates = NULL,
  brightness = 5,
  global_brightness = 0.05
)

Arguments

file: Character. Path to a multi-band raster file (e.g., PlanetScope SR clip).
df_coordinates: Optional data frame. Point locations to overlay; must contain lon, lat, and site. Default: NULL.
brightness: Numeric. Brightness multiplier for RGB values (slider value, default: 5).
global_brightness: Numeric. The global average brightness (from sampled images at app startup).

Value

A ggplot2 object.

Examples

if (FALSE) { # \dontrun{
visualize_true_color_imagery(
  file = "alldata/PSdata/raw/SJER/20240501_SR_harmonized_clip.tif",
  df_coordinates = df_coordinates_SJER,
  brightness = 5,
  global_brightness = 0.05
)
} # }