A function that requests images of the CDL data for an area of interests in a given year from the CropScape. This function implements the GetCDLImage service provided by the CropScape https://nassgeodata.gmu.edu/CropScape.
GetCDLImage(
aoi = NULL,
year = NULL,
type = NULL,
format = "png",
crs = NULL,
destfile = NULL,
verbose = TRUE,
tol_time = 20
)The function downloads an image file in png or kml format to users' computer. This function is different to GetCDLData that returns a raster TIF file.
Area of interest. Can be a 5-digit FIPS code of a county, 2-digit FIPS code of a state, four corner points or an sf object that defines a rectangle (or a box) area, multiple coordinates that defines a polygon, or a URL of an compressed ESRI shapefile.
Year of data. Should be a 4-digit numeric value.
Type of the selected AOI. 'f' for state or county, 'b' for box area, 'ps' for polygon, 's' for ESRI shapefile.
Format of the image file. Can be png or kml.
Coordinate system. NULL if use the default coordinate system (i.e., Albers projection); Use '+init=epsg:4326' for longitude/latitude.
A character string that specifies the directory to save the downloaded image file (e.g., 'C:/image.png'). Note that
the name of the image file should be specified as well. If not providing destfile, the function will create a temporary folder to save the image file.
TRUE/FALSE. Display the directory saving the file or not.
Number of seconds to wait for a response until giving up. Default is 20 seconds.
The usage of this function is similar to the GetCDLData function. Please see the help page of the GetCDLData function
for details. Note that the aoi cannot be a single point here.