GetImageBy...: Get image from the archive (vectorization ready)

Description

These functions retrieve the image for the area of interest using the parameters provided. They are simple wrappers around the 'GetImage' function with arguments organized in a way that facilitates calling the function in a vectorized manner (using 'lapply' or similar function) and thus potentially also the parallelization.

Usage

GetImageByTimerange(
  time_range,
  aoi,
  bbox,
  collection,
  script,
  file = NULL,
  format = c("image/tiff", "image/png", "image/jpeg"),
  mosaicking_order = c("mostRecent", "leastRecent", "leastCC"),
  pixels,
  resolution,
  buffer = 0,
  mask = FALSE,
  client,
  token,
  url = getOption("CDSE.process_url")
)
GetImageByAOI(
  aoi,
  time_range,
  collection,
  script,
  file = NULL,
  format = c("image/tiff", "image/png", "image/jpeg"),
  mosaicking_order = c("mostRecent", "leastRecent", "leastCC"),
  pixels,
  resolution,
  buffer = 0,
  mask = FALSE,
  client,
  token,
  url = getOption("CDSE.process_url")
)
GetImageByBbox(
  bbox,
  time_range,
  collection,
  script,
  file = NULL,
  format = c("image/tiff", "image/png", "image/jpeg"),
  mosaicking_order = c("mostRecent", "leastRecent", "leastCC"),
  pixels,
  resolution,
  buffer = 0,
  mask = FALSE,
  client,
  token,
  url = getOption("CDSE.process_url")
)

Value

SpatRaster object (from the package terra) of the requested image (if file is NULL), or the (invisible) name of the file created.

Arguments

time_range

scalar or vector (Date or character that can be converted to date) defining the time interval.

aoi

sf or sfc object, typically a (multi)polygon, describing the Area of Interest.

bbox

numeric vector of four elements describing the bounding box of interest. Specify with a coordinate pair on two (opposite) vertices of the bounding box rectangle. Coordinates need to be in longitude, latitude.

Only one of either aoi or bbox may be specified.

collection

character indicating which collection to search. Must be one of the collections returned by GetCollections.

script

a length one character string containing the evaluation script or the name of the file containing the script.

file

name of the file to save the image. If NULL, a SpatRaster object is returned. Default: NULL

format

character indicating the output file format. Must be one of "image/tiff", "image/png", or "image/jpeg". Default: "image/tiff"

mosaicking_order

character indicating the order in which tiles are overlapped from which the output result is mosaicked. Must be one of "mostRecent", "leastRecent", or "leastCC". Default: "mostRecent"

pixels

integer scalar or length-two vector indicating the request image width and height. Values must be integers between 1 and 2500.

resolution

numeric scalar or length-two vector indicating the spatial resolution of the request image in horizontal and vertical direction (in meters).

Only one of the arguments "pixels" or "resolution" must be set at the same time. If the argument "pixels" or "resolution" is scalar, the same value is used for horizontal and vertical direction (width and height).

buffer

numeric, width of the buffer to retrieve the image of enlarged area. Default: 0

mask

logical indicating if the image should contain only pixels within Area of Interest. Default: FALSE

client

OAuth client object to use for authentication.

token

OAuth token character string to use for authentication.

Exactly one of either client or token must be specified. It is recommended to use client.

url

character indicating the process endpoint. Default: Copernicus Data Space Ecosystem process endpoint

Details

If aoi argument is provided, the result is returned in the same coordinate reference system.

GetImageByTimerange is arranged for vectorization on time_range (time_range is the first argument).

GetImageByAOI is arranged for vectorization on aoi (aoi is the first argument).

GetImageByBbox is arranged for vectorization on bbox (bbox is the first argument).

Examples

Run this code

if (FALSE) {
dsn <- system.file("extdata", "centralpark.geojson", package = "CDSE")
aoi <- sf::read_sf(dsn, as_tibble = FALSE)
cloudless_images <- SearchCatalog(aoi = aoi, from = "2023-01-01", to = "2023-12-31",
                    collection = "sentinel-2-l2a", with_geometry = TRUE,
                    filter = "eo:cloud_cover < 0.8", client = OAuthClient)
script_file <- system.file("scripts", "NDVI_float32.js", package = "CDSE")
days <- rev(cloudless_images$acquisitionDate)
lstRast <- lapply(days, GetImageByTimerange, aoi = aoi, collection = "sentinel-2-l2a",
    script = script_file, file = NULL, format = "image/tiff", mosaicking_order = "mostRecent",
    resolution = 10, buffer = 0, mask = TRUE, client = OAuthClient,
    url = getOption("CDSE.process_url"))
par(mfrow = c(3, 4))
sapply(seq_along(days), FUN = function(i) {
     ras <- lstRast[[i]]
     day <- days[i]
     ras[ras < 0] <- 0
     terra::plot(ras, main = paste("Central Park NDVI on", day), range = c(0, 1),
            cex.main = 0.7, pax = list(cex.axis = 0.5), plg = list(cex = 0.5),
            col = colorRampPalette(c("darkred", "yellow", "darkgreen"))(99))
     })
}