getPixmapGDAL {rgdal}R Documentation

Read GDAL datasets as pixmapGrey or pixmapRGB objects

Description

A wrapper function for getRasterData() to insert the retrieved data into pixmap objects; only implemented now for greyscale and RGB data.

Usage

getPixmapGDAL(dataset, col=NULL, band = NULL, offset = c(0, 0), region.dim = dim(dataset), output.dim = region.dim, interleave = c(0, 0), stretch.bands = TRUE, as.is = FALSE)

Arguments

dataset An object inheriting from class 'GDALReadOnlyDataset'
col a vector of colours or a colour function such as rainbow
band The band number (1-based) to read from
offset Number of rows and columns from the origin (usually the upper left corner) to begin reading from
region.dim The number of rows and columns to read from the dataset
output.dim Number of rows and columns in the output data; if smaller than region.dim the data will be subsampled
interleave Element and row stride while reading data; rarely needed
stretch.bands if TRUE, stretch 3-band RGB images
as.is If false, scale the data to its natural units; if the case of thematic data, return the data as factors

Value

For single band data, returns a "pixmapGrey" object, for three band data, a "pixmapRGB" object.

Author(s)

Roger Bivand

See Also

GDALRasterBand-class

Examples

logo <- system.file("pictures/logo.jpg", package="rgdal")[1]
x <- new("GDALReadOnlyDataset", logo)
xGrey <- getPixmapGDAL(x)
xGrey
plot(xGrey)
xCm <- getPixmapGDAL(x, col=cm.colors)
xCm
plot(xCm)
GDAL.close(x)
Rlogo <- system.file("pictures/Rlogo.jpg", package="rgdal")[1]
y <- new("GDALReadOnlyDataset", Rlogo)
yRGB <- getPixmapGDAL(y)
yRGB
plot(yRGB)
GDAL.close(y)

[Package rgdal version 0.4-4 Index]