Internal function to create JPEG images from a multiband raster file. This function is used by s2_thumbnails, and it will be exported when it would be more generalised.
stack2rgb( in_rast, out_file = NULL, bands = 1:3, minval = 0, maxval = 10000, format = "JPEG", compress = "90", bigtiff = FALSE, proc_mode = "raster", tmpdir = NA )
in_rast | Input raster (as |
---|---|
out_file | (optional) Path of the output RGB JPEG image; if NULL (default), a RasterBrick will be returned. |
bands | (optional) 3-length integer argument, with the position of the three bands to be used respectively for red, green and blue. |
minval | (optional) the value corresponding to black (default: 0). Also a 3-length vector is accepted (min values for red, green and blue respectively). |
maxval | (optional) the value corresponding to white (default: 10000). Also a 3-length vector is accepted (max values for red, green and blue respectively). |
format | (optional) Format of the output file (in a format recognised by GDAL). Default is JPEG. |
compress | (optional) In the case a GTiff format is present, the compression indicated with this parameter is used. In the case a JPEG format is present, the compression indicates the quality (integer, 0-100). In the case a GTiff format is present and an integer 0-100 number is provided, this is interpreted as the quality level of a JPEG compression. |
bigtiff | (optional) Logical: if TRUE, the creation of a BigTIFF is forced (default is FALSE). This option is used only in the case a GTiff format was chosen. |
proc_mode | (optional) Character: if |
tmpdir | (optional) Path where intermediate files will be created.
Default is a temporary directory.
If |
The path of the output image; alternatively, the output image
as RasterBrick (if out_rast = NULL
).
License: GPL 3.0
L. Ranghetti, M. Boschetti, F. Nutini, L. Busetto (2020). "sen2r": An R toolbox for automatically downloading and preprocessing Sentinel-2 satellite data. Computers & Geosciences, 139, 104473. DOI: 10.1016/j.cageo.2020.104473, URL: http://sen2r.ranghetti.info/.