stack2rgb: Produce an RGB image from a multiband raster file.

In sen2r: Find, Download and Process Sentinel-2 Data

Produce an RGB image from a multiband raster file.

Description

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.

Usage

stack2rgb(
  in_rast,
  out_file = NULL,
  bands = 1:3,
  minval = 0,
  maxval = 10000,
  format = "JPEG",
  compress = "90",
  bigtiff = FALSE,
  proc_mode = "raster",
  tmpdir = NA
)

Arguments

in_rast	Input raster (as ⁠Raster*⁠ or stars object).
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 "gdal_calc", gdal_calc routines are used to compute indices; if "raster" (default) or "stars", R functions are instead used (using respectively raster or stars routines). Note: default value ("raster") is the only fully supported mode. "gdal_calc" can be used only if a runtime GDAL environment can be properly configured (no assistance is provided in case of GDAL-related problems). "raster" mode is experimental. See s2_calcindices() for further details.
tmpdir	(optional) Path where intermediate files will be created. Default is a temporary directory. If tmpdir is a non-empty folder, a random subdirectory will be used.

Value

The path of the output image; alternatively, the output image as RasterBrick (if out_rast = NULL).

Note

License: GPL 3.0

Author(s)

Luigi Ranghetti, phD (2019)

References

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. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1016/j.cageo.2020.104473")}, URL: https://sen2r.ranghetti.info/.

sen2r documentation built on Nov. 10, 2023, 9:08 a.m.