rgee (version 0.5.0)

ee_image_to_gcs: Creates a task to export an EE Image to Google Cloud Storage.

Description

Creates a task to export an EE Image to Google Cloud Storage. This function is a wrapper around ee$batch$Export$image$toCloudStorage(...).

Usage

ee_image_to_gcs(
  image,
  description = "myExportImageTask",
  bucket = NULL,
  fileNamePrefix = NULL,
  timePrefix = TRUE,
  dimensions = NULL,
  region = NULL,
  scale = NULL,
  crs = NULL,
  crsTransform = NULL,
  maxPixels = NULL,
  shardSize = NULL,
  fileDimensions = NULL,
  skipEmptyTiles = NULL,
  fileFormat = NULL,
  formatOptions = NULL
)

Arguments

image

The image to be exported.

description

Human-readable name of the task.

bucket

The name of a Cloud Storage bucket for the export.

fileNamePrefix

Cloud Storage object name prefix for the export. Defaults to the name of the task.

timePrefix

Add current date and time as a prefix to files to export.

dimensions

The dimensions of the exported image. Takes either a single positive integer as the maximum dimension or "WIDTHxHEIGHT" where WIDTH and HEIGHT are each positive integers.

region

The lon,lat coordinates for a LinearRing or Polygon specifying the region to export. Can be specified as a nested lists of numbers or a serialized string. Defaults to the image's region.

scale

The resolution in meters per pixel. Defaults to the native resolution of the image assset unless a crsTransform is specified.

crs

The coordinate reference system of the exported image's projection. Defaults to the image's default projection.

crsTransform

A comma-separated string of 6 numbers describing the affine transform of the coordinate reference system of the exported image's projection, in the order: xScale, xShearing, xTranslation, yShearing, yScale and yTranslation. Defaults to the image's native CRS transform.

maxPixels

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.

shardSize

Size in pixels of the shards in which this image will be computed. Defaults to 256.

fileDimensions

The dimensions in pixels of each image file, if the image is too large to fit in a single file. May specify a single number to indicate a square shape, or a list of two dimensions to indicate (width,height). Note that the image will still be clipped to the overall image dimensions. Must be a multiple of shardSize.

skipEmptyTiles

If TRUE, skip writing empty (i.e. fully-masked) image tiles. Defaults to FALSE.

fileFormat

The string file format to which the image is exported. Currently only 'GeoTIFF' and 'TFRecord' are supported, defaults to 'GeoTIFF'.

formatOptions

A dictionary of string keys to format specific options. **kwargs: Holds other keyword arguments that may have been deprecated such as 'crs_transform'.

Value

An unstarted Task that exports the image to Google Cloud Storage.

Examples

# NOT RUN {
library(rgee)
library(stars)
library(sf)

ee_users()
ee_reattach() # reattach ee as a reserved word
ee_Initialize(gcs = TRUE)

# Define study area (local -> earth engine)
# Communal Reserve Amarakaeri - Peru
rlist <- list(xmin = -71.13, xmax = -70.95,ymin = -12.89, ymax = -12.73)
ROI <- c(rlist$xmin, rlist$ymin,
         rlist$xmax, rlist$ymin,
         rlist$xmax, rlist$ymax,
         rlist$xmin, rlist$ymax,
         rlist$xmin, rlist$ymin)
ee_ROI <- matrix(ROI, ncol = 2, byrow = TRUE) %>%
  list() %>%
  st_polygon() %>%
  st_sfc() %>%
  st_set_crs(4326) %>%
  sf_as_ee()


# Get the mean annual NDVI for 2011
cloudMaskL457 <- function(image) {
  qa <- image$select("pixel_qa")
  cloud <- qa$bitwiseAnd(32L)$
    And(qa$bitwiseAnd(128L))$
    Or(qa$bitwiseAnd(8L))
  mask2 <- image$mask()$reduce(ee$Reducer$min())
  image <- image$updateMask(cloud$Not())$updateMask(mask2)
  image$normalizedDifference(list("B4", "B3"))
}

ic_l5 <- ee$ImageCollection("LANDSAT/LT05/C01/T1_SR")$
  filterBounds(ee_ROI)$
  filterDate("2011-01-01", "2011-12-31")$
  map(cloudMaskL457)

# Create simple composite
mean_l5 <- ic_l5$mean()$rename("NDVI")
mean_l5 <- mean_l5$reproject(crs = "EPSG:4326", scale = 500)
mean_l5_Amarakaeri <- mean_l5$clip(ee_ROI)

# Move results from Earth Engine to Drive
task_img <- ee_image_to_gcs(
  image = mean_l5_Amarakaeri,
  bucket = "rgee_dev",
  fileFormat = "GEO_TIFF",
  region = ee_ROI$geometry(),
  fileNamePrefix = "my_image"
)

task_img$start()
ee_monitoring(task_img)

# Move results from Drive to local
ee_gcs_to_local(task = task_img)
plot(img)
# }