I have two rasters (raster1 and raster2). The raster1 extent is smaller than raster2. I want to replace the value of raster2 pixels using raster1 pixels. How can I replace the values?
[GIS] How to replace cell values of a raster using values of another raster with differing extent
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Related Solutions
This can easily be solved using the overlay function from the raster package. Objects rst1 and rst2 are replicates of the initial 'volcano' layer, and a random sample of n = 1000 cells in rst2 is set to NA. Afterwards, overlay is applied and the associated function rejects all cells in rst1 that hold a valid value, i.e. different from NA, in rst2.
library(raster)
rst <- raster::raster(volcano)
rst1 <- rst
rst2 <- rst
# artificial gaps
set.seed(123)
id <- sample(1:ncell(rst), 1000)
rst2[id] <- NA
# introduce na in rst1 for all locations that are non-na in rst2
rst1_mod <- overlay(rst1, rst2, fun = function(x, y) {
x[!is.na(y[])] <- NA
return(x)
})
plot(rst1_mod)
Best Answer
Is it acceptable for you to use GDAL? If it is then you can do what you want with gdalwarp http://www.gdal.org/gdalwarp.html
The command to use is
Command will write data from source image "raster1.tif" into target image "raster2.tif" and if the target image already exists and is of such a format that can be updated then pixels from raster1 will be written over the original pixels. Uncompressed geotiff is good for the output format. You can compress or convert the updated image afterwards if needed.