GetHighResolutionImage: Get image limited to an area of interest

Description

Provides you with a high resolution image for the area within the acquisition boundaries, if you're not interested in downloading the whole image.

Usage

GetHighResolutionImage(
  aoi,
  id,
  bands,
  width,
  height,
  file = "image.jpg",
  api_key = Sys.getenv("spectator_earth_api_key")
)

Value

The name of the image file is returned invisibly.

Arguments

aoi: 'sf' (or 'Spatial*') object defining the area of interest. Can be of any geometry as only the bounding box is used.
id: integer, id of the image from the SearchImages result
bands: integer vector of length 1 or 3 indicating the spectral bands to use for creating the image (typically the bands corresponding to Red, Green and Blue)
width: integer indicating the width of the image (in pixels)
height: integer indicating the height of the image (in pixels)
file: character indicating the name of the image file to create. Default: 'image.jpg'
api_key: character containing your API key. Default: Sys.getenv("spectator_earth_api_key")

Details

As a side effect, the image file is written to the provided path.

Examples

Run this code

if(interactive()){
 library(sf)
 my_key <- Sys.getenv("spectator_earth_api_key")
 # get the New York City Central Park shape as area of interest
 dsn <- system.file("extdata", "centralpark.geojson", package = "spectator")
 boundary <- sf::read_sf(dsn, as_tibble = FALSE)
 # search for May 2021 Sentinel 2 images 
 catalog <- SearchImages(aoi = boundary, satellites = "S2", 
     date_from = "2021-05-01", date_to = "2021-05-30", 
     footprint = FALSE, api_key = my_key)
 # get the id of the image with minimal cloud coverage
 best_id <- catalog[order(catalog$cloud_cover_percentage), ][1, "id"]
 # get the high resolution image of the Central Park
 img <- GetHighResolutionImage(aoi = boundary, id = best_id, bands = c(4, 3, 2), 
     width = 1024, height = 1024,
     file = tempfile(pattern = "img", fileext = ".jpg"), 
     api_key = my_key)
 }