/*! \page read_raster Reading a raster dataset

The code here does not have any warranty. It is recommended that
before using any of this code, you look into it and try to understand
what it does, what input it needs, etc. Do not blindly execute
anything!

\code
use Geo::GDAL;

$file = shift @ARGV;

$dataset = Geo::GDAL::Open($file);
die "can't open $file as a raster dataset" unless $dataset;

($minx, $dx, undef, $maxy, undef, $dy) = $dataset->GeoTransform();
($width, $height) = $dataset->Size;
$band = $dataset->GetRasterBand(1);

$data = $band->ReadTile;

print @$data == $height ? "ok\n" : "not ok\n";
\endcode

*/