Hi Oliver, You can create very large GeoTiffs by creating the image such that you don't try to hold all of it in memory at one time. The standard approach is to use a tiled image. The example below uses the JAI "Constant" operation to create the tiles for a large image. This is then wrapped in a GridCoverage2D object and written to file as a GeoTiff.
You might also be interested in the jai-tools project which has a tiled image class that can use both disk and memory storage for working with images too large to fit into available memory. This is a good option when, unlike in the example below, the image is costly to generate, e.g. the product of a complex and time-consuming calculation. http://code.google.com/p/jai-tools/wiki/DiskMemImage Hope this helps, Michael /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package org.geotools.demo.coverage; import java.awt.Rectangle; import java.awt.RenderingHints; import java.awt.image.Raster; import java.io.File; import javax.media.jai.ImageLayout; import javax.media.jai.JAI; import javax.media.jai.ParameterBlockJAI; import javax.media.jai.RenderedOp; import org.geotools.coverage.grid.GridCoverage2D; import org.geotools.coverage.grid.GridCoverageFactory; import org.geotools.gce.geotiff.GeoTiffWriter; import org.geotools.geometry.jts.ReferencedEnvelope; import org.geotools.swing.data.JFileDataStoreChooser; /** * This example illustrates creating a large coverage, avoiding the need to hold * all of the data in memory at one time. * * @author Michael Bedward */ public class BigCoverage { private static final int IMAGE_WIDTH = 10000; private static final int IMAGE_HEIGHT = 10000; public static void main(String[] args) throws Exception { JFileDataStoreChooser chooser = new JFileDataStoreChooser("tif"); chooser.setDialogTitle("Create GeoTiff file"); File file = null; if (chooser.showSaveDialog(null) == JFileDataStoreChooser.APPROVE_OPTION) { file = chooser.getSelectedFile(); } if (file == null) { return; } ParameterBlockJAI pb = new ParameterBlockJAI("Constant"); pb.setParameter("width", (float)IMAGE_WIDTH); pb.setParameter("height", (float)IMAGE_HEIGHT); pb.setParameter("bandValues", new Double[]{0.0d}); final int tileWidth = 512; ImageLayout layout = new ImageLayout(); layout.setTileWidth(tileWidth); layout.setTileHeight(tileWidth); RenderingHints hints = new RenderingHints(JAI.KEY_IMAGE_LAYOUT, layout); RenderedOp image = JAI.create("Constant", pb, hints); for (int y = 0; y < image.getNumYTiles(); y++) { for (int x = 0; x < image.getNumXTiles(); x++) { Raster tile = image.getTile(x, y); System.out.println(String.format("calling getTile(%d, %d): %s", x, y, tile.getBounds().toString())); } } GeoTiffWriter writer = new GeoTiffWriter(file, null); GridCoverageFactory factory = new GridCoverageFactory(); ReferencedEnvelope env = new ReferencedEnvelope( new Rectangle(0, 0, IMAGE_WIDTH, IMAGE_HEIGHT), null); GridCoverage2D coverage = factory.create("coverage", image, env); writer.write(coverage, null); } } ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Geotools-gt2-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
