Creating 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!

This example will create a raster dataset with one band and with cell value of type Float32. The raster will be stored as a !GeoTiff and it will have undefined SRS. The coordinates of the upper left vertex are known and the size of each pixel. Pixels are squares.

use Geo::GDAL;

$name = "raster";     # name (without extension) for the new raster
$datatype = 'Float32';# datatype for the values in pixels
$width = 100;         # number of pixels in x direction
$height = 100;        # number of pixels in y direction
$minx = 12.3;         # x of the left border of leftmost pixel
$dx = 0.1;            # width of pixels
$maxy = 14.5;         # y of the top border of topmost pixel
$dy = -0.1;           # height of pixels, negative means miny < maxy
$nodata = -1;         # nodata value
@data = ();           # pixel values, stored in this example in a hash

# note: things that are hardcoded:
# We create a GTiff and set the extension to '.tiff'.
# We add only one band to the raster.

$dataset = Geo::GDAL::Driver('GTiff')->Create($name.'.tiff', $width, $height, 1, $datatype);
$dataset->GeoTransform($minx, $dx, 0, $maxy, 0, -$dy);
$band = $dataset->Band(1);
$band->NoDataValue($nodata);

for (1..100) {
    push @data, [1..100];
}
$band->WriteTile(\@data);
@data = ();
for $i (0..19) {
    for $j (0..29) {
        $data[$i][$j] = $nodata;
    }
}
$band->WriteTile(\@data,10,20);