Generate a raster with the values from the first raster, but only include cells in which the corresponding cell in the second raster *are not* set to the "readMask" value.
Generate a raster with the values from the first raster, but only include cells in which the corresponding cell in the second raster *are not* set to the "readMask" value.
For example, if *all* cells in the second raster are set to the readMask value, the output raster will be empty -- all values set to NODATA.