Convert RGB three band to single band colour table
This function converts a three-band GDALReadOnlyDataset into a single band of colour indices as a GDALTransientDataset.
RGB2PCT(x, band, driver.name = 'MEM', ncolors = 256, set.ctab = TRUE)
x |
a three-band GDALReadOnlyDataset object |
band |
a vector of numbers, recycled up to 3 in length |
driver.name |
default MEM |
ncolors |
a number of colours between 2 and 256 |
set.ctab |
default TRUE, when the dithered dataset handle is returned, otherwise a list of the dataset and the PCT colour table |
The value returned is a either GDALTransientDataset or a list of a GDALTransientDataset and a colour table.
Tim Keitt
## Not run:
logo <- system.file("pictures/Rlogo.jpg", package="rgdal")[1]
x <- GDAL.open(logo)
dim(x)
dx <- RGB2PCT(x, band=1:3)
displayDataset(dx, reset.par=FALSE)
dim(dx)
GDAL.close(x)
GDAL.close(dx)
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.