R: Rlogo jpeg image

Rlogo {sp} | R Documentation

## Rlogo jpeg image

### Description

Rlogo jpeg image data as imported by `getRasterData` in the rgdal package

### Usage

    data(Rlogo)

### Format

The format is: int [1:101, 1:77, 1:3] 255 255 255 255 255 255 255 255 255 255 ...

### Examples

    ## Not run:
    library(rgdal)
    logo <- system.file("pictures/Rlogo.jpg", package="rgdal")[1]
    x <- GDAL.open(logo)
    gt = .Call('RGDAL_GetGeoTransform', x, PACKAGE="rgdal")
    data <- getRasterData(x)
    GDAL.close(x)

    ## End(Not run)
    data(Rlogo)
    d = dim(Rlogo)
    cellsize = abs(c(gt[2],gt[6]))
    cells.dim = c(d[1], d[2]) # c(d[2],d[1])
    cellcentre.offset = c(x = gt[1] + 0.5 * cellsize[1], y = gt[4] - (d[2] - 0.5) * abs(cellsize[2]))
    grid = GridTopology(cellcentre.offset, cellsize, cells.dim)
    df = as.vector(Rlogo[,,1])
    for (band in 2:d[3]) df = cbind(df, as.vector(Rlogo[,,band]))
    df = as.data.frame(df)
    names(df) = paste("band", 1:d[3], sep="")
    Rlogo <- SpatialGridDataFrame(grid = grid, data = df)
    summary(Rlogo)
    spplot(Rlogo, zcol=1:3, names.attr=c("red","green","blue"),
    	col.regions=grey(0:100/100),
    	main="example of three-layer (RGB) raster image", as.table=TRUE)

[Package sp version 1.3-2 Index]