[GIS] Create image (TIFF/PNG) from geodetic (lat/long) data

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Using Java, I need to render a bunch of geodetic data to an image, ideally TIFF or PNG. Specifically this is weather data, with each sample having a latitude, longitude, and amplitude value.

I'd like to avoid reinventing the wheeling by converting polar coordinates (lat, long) to Cartesian coordinates (x, y in BufferedImage or Graphics2D). Furthermore the amplitude value needs to rendered as a color gradient. I've looks at GeoTools and NASA's World Wind, but it's unclear and not obvious if it has this capability.

Is there a Java library that can do this?

Best Answer

Did you consider using GDAL? Extensive information, Documentation and examples are available on the Geographical Data Abstraction Library. You can get step-by-step help to compile the GDAL.jar library as described here

gdal.ReprojectImage(src_ds, dst_ds) from from GDAL Class seems to be what you are looking for though I have never used it yet.

Related Solutions

[GIS] Create GeoTIFF from TIFF using Java

You can use java library: GeoTiff-JAI.

More is in this post: https://stackoverflow.com/questions/3716462/how-can-i-write-a-geotiff-in-java

[GIS] GeoToolKit conversion from lat/long to UTM

I figured it out. Here is the solution in case anyone else is interested. UTM is not a single projection, but actually a set of 120 different UTM zones. The zones are divided in 6 deg increments starting at -180 deg longitude, continuing to 180 deg longitude. This creates 60 zones, and since there is a northern and southern zone for each range, the total becomes 120.

Update: As mentioned below, this is a simplification of the UTM standard, and will not be accurate for a few unique regions around Norway.

The next hurdle is then converting the UTM zone to the EPSG database code, so it can be retrieved using the geotoolkit API. The code makes it clear how the EPSG code can be reached, once you've figured out the UTM zone.

private static int utm_zone( double _long ){
  assert _long > -180.0 && _long < 180.0;
  return (int)(Math.ceil((180 + _long)/6.0));
}

public void asUTMCoordinates( double longitude, double latitude) throws
     MismatchedDimensionException, TransformException {

  Point p = FactoryFinder.getPrimitiveFactory(null).createPoint( new double[] {longitude,latitude} );

  // define base EPSG code value of all UTM zones;
  int epsg_code = 32600;
  // add 100 for all zones in southern hemisphere
  if (this.getLatitudeInDeg() < 0) {
     epsg_code += 100;
  }
  // finally, add zone number to code
  final int zone = utm_zone( longitutde );
  epsg_code += zone;

  MathTransform crs_transform;
  try {
     CoordinateReferenceSystem wgs84  = DefaultGeographicCRS.WGS84; // EPSG:4326
     CoordinateReferenceSystem utm    = CRS.decode("EPSG:"+epsg_code);
     crs_transform = CRS.findMathTransform(wgs84,utm);
  } catch (NoSuchAuthorityCodeException e) {
     throw new RuntimeException(e);
  } catch (FactoryException e) {
     throw new RuntimeException(e);
  }
  DirectPosition p2 = crs_transform.transform( p.getDirectPosition(), null );
  double[] c = p2.getCoordinate();
  System.out.println( String.format("%d, %f, %f", zone, c[0], c[1]) );
}

Best Answer

Related Solutions

[GIS] Create GeoTIFF from TIFF using Java

[GIS] GeoToolKit conversion from lat/long to UTM

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