as.im.RasterLayer <-
  function (from)
  {
    if (!requireNamespace("spatstat", quietly = TRUE))
      stop("package spatstat required for coercion")
    if (!requireNamespace("raster", quietly = TRUE))
      stop("package raster required for coercion")
    if (!raster::hasValues(from))
      stop("values required in RasterLayer object")
    if (raster::rotated(from)) {
      stop(
        "\n Cannot coerce because the object is rotated.\n Either coerce to SpatialPoints* from\n or first use the \"rectify\" function"
      )
    }
    rs <- raster::res(from)
    orig <- bbox(from)[, 1] + 0.5 * rs
    dm <- dim(from)[2:1]
    xx <- unname(orig[1] + cumsum(c(0, rep(rs[1], dm[1] - 1))))
    yy <- unname(orig[2] + cumsum(c(0, rep(rs[2], dm[2] - 1))))
    
    if(is.factor(from) == T){
      mat <- factor(raster::values(from))
      dim(mat) <- dm
      im <- spatstat::im(mat,
                         xcol = yy, yrow = xx)
      im <- spatstat::rotate.im(im, angle = -pi / 2)
    }else{
      im <- spatstat::im(matrix(raster::values(from), ncol = dm[1], 
                                nrow = dm[2], byrow = TRUE)[dm[2]:1, ], xcol = xx, yrow = yy)
    }
    
    im
  }