Add logo png to spplot in r

Question

I need to add logo png image to my spplot as a map element. Can tell me the way how input logo as into spplot?? This is my r code.

im <- raster("LMB_KBDI_2013-01-01.tif")
proj <- CRS('+proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0')

#Plot SPPlot
mrc <- readShapePoly('E:/MRC/LMB_Country.shp', proj4string=proj)
polys <- list("sp.lines", as(mrc, "SpatialLines"), col="black")
DROUGHTcolors <- colorRampPalette(c("lightyellow","yellow","orange","red"))
north <- list("SpatialPolygonsRescale", layout.north.arrow(), offset=c(107.5,20), scale=1.5)
txt1 <- list("sp.text", c(100,9.8), "0`")
txt2 <- list("sp.text", c(102,9.8), "2`")
scale <- list("SpatialPolygonsRescale", layout.scale.bar(), offset=c(100,10), scale=2, fill=c("transparent","black"))

img.layout <- list(polys, north,txt1, txt2, scale)
CUTS1 <- c(0, 200, 400, 600, 800)
CUTS11 <- c(100, 300, 500, 700)

spplot(
 im, 
 sp.layout=img.layout, 
 col.regions = DROUGHTcolors, 
 scales=list(draw=TRUE), 
 colorkey=list(
   draw=TRUE, space = "right", at=CUTS1, 
   labels=list(
   at=CUTS11, 
   labels=c(
    "Normal","Abnormally Dry","Moderate Dry","Severe Dry"
   ), cex.lab= 1.5
 )
 ), 
 at=CUTS1,  main = list(paste("Drought Map of Lower Mekong River Basin -"), cex=2)
 )

Answer 1

With grid.raster you can include an image in your plot. Define a new list with it, and add it as a new component to your img.layout:

library(grid)
library(png)

img <- readPNG(system.file("img", "Rlogo.png", package="png"), native=TRUE)
## Define x, y, and width/height to position and resize the logo
logo <- list("grid.raster", img, 
             x = x, y = y, width = width, 
             default.units='native')

img.layout <- list(polys, north,txt1, txt2, scale, logo)

spplot(im, sp.layout=img.layout)

Please, next time provide a reproducible example.