rgee (version 0.5.0)

ee_as_raster: Convert an Earth Engine (EE) image into a raster object

Description

Convert an ee$Image into a raster object

Usage

ee_as_raster(
  image,
  region,
  dsn = NULL,
  via = "getInfo",
  scale = NULL,
  maxPixels = 1e+09,
  container = "rgee_backup",
  quiet = FALSE
)

Arguments

image

ee$Image to be converted into a raster object

region

EE Geometry Rectangle (ee$Geometry$Rectangle). The CRS needs to be the same that the x argument otherwise it will be forced. If not specified, image bounds will be taken.

dsn

Character. Output filename. If missing, ee_as_raster will create a temporary file.

via

Character. Method to fetch data about the object. Multiple options supported. See details.

scale

Numeric. The resolution in meters per pixel. Defaults to the native resolution of the image asset.

maxPixels

Numeric. The maximum allowed number of pixels in the exported image. The task will fail if the exported region covers more pixels in the specified projection. Defaults to 100,000,000.

container

Character. Name of the folder ('drive') or bucket ('gcs') to be exported into (ignored if via is not defined as "drive" or "gcs").

quiet

Logical. Suppress info message

Value

A RasterStack object

Details

ee_as_raster supports the download of ee$Image by three different options: "getInfo", "drive", and "gcs". When "getInfo" is set in the via argument, ee_as_stars will make a REST call to retrieve all the known information about the object. The advantage of using "getInfo" is performing a quick download. However, there is a limitation of 262144 pixels by request which makes it not recommendable for large images. Instead of "getInfo", the options: "drive" and "gcs" are suitable for large collections since they use an intermediate web store service. Before using any of these options, it is necessary previously to install the R packages googledrive and googleCloudStorageR. For getting more information about exporting data take a look at the Google Earth Engine Guide - Export data.

Examples

# NOT RUN {
library(rgee)

ee_reattach()
ee_Initialize(drive = TRUE, gcs = TRUE)
ee_user_info()

# Define an image.
img <- ee$Image("LANDSAT/LC08/C01/T1_SR/LC08_038029_20180810")$
  select(c("B4", "B3", "B2"))$
  divide(10000)

# OPTIONAL display it using Map
Map$centerObject(eeObject = img)
Map$addLayer(eeObject = img, visParams = list(max = 0.4,gamma=0.1))

# Define an area of interest.
geometry <- ee$Geometry$Rectangle(
  coords = c(-110.8, 44.6, -110.6, 44.7),
  proj = "EPSG:4326",
  geodesic = FALSE
)

## getInfo - Option 01
img_01 <- ee_as_raster(
  image = img,
  region = geometry,
  via = "getInfo"
)

## drive - Method 02
img_02 <- ee_as_raster(
  image = img,
  region = geometry,
  via = "drive"
)

## gcs - Method 03
img_03 <- ee_as_raster(
  image = img,
  region = geometry,
  container = "rgee_dev",
  via = "gcs"
)

# OPTIONAL: Delete containers
ee_clean_container(
  name = "rgee_backup",
  type = "drive"
)
ee_clean_container(
  name = "rgee_dev",
  type = "gcs"
)
# }