Display a GDAL dataset allowing for subscenes and decimation, allowing very large images to be browsed

displayDataset(x, offset=c(0, 0), region.dim=dim(x), reduction = 1, 
  band = 1, col = NULL, reset.par = TRUE, max.dim = 500, ...)

Arguments

x

a three-band GDALReadOnlyDataset object

offset

Number of rows and columns from the origin (usually the upper left corner) to begin reading from; presently ordered (y,x) - this may change

region.dim

The number of rows and columns to read from the dataset; presently ordered (y,x) - this may change

reduction

a vector of length 1 or 2 recycled to 2 for decimating the input data, 1 retains full resultion, higher values decimate

band

The band number (1-based) to read from

col

default NULL, attempt to use band colour table and default to grey scale if not available

reset.par

default TRUE - reset par() settings on completion

max.dim

default 500, forcing the image to a maximum dimension of the value

...

arguments passed to image.default()

Value

a list of the image data, the colour table, and the par() values on entry.

References

https://gdal.org/

Author

Tim Keitt

Examples

if (FALSE) { logo <- system.file("pictures/Rlogo.jpg", package="rgdal")[1] x <- GDAL.open(logo) opar <- par(no.readonly=TRUE) par(mfrow=c(2,2)) displayDataset(x, band=1, reset.par=FALSE) displayDataset(x, band=2, reset.par=FALSE) #displayDataset(x, band=3, reset.par=TRUE) par(opar) dx <- RGB2PCT(x, band=1:3) displayDataset(dx, reset.par=FALSE) GDAL.close(x) GDAL.close(dx) }