How to convert raster tiles into buffered images?

Question

Abstract:
Using the code below i try to render four tiles of an image and then store them in different files. Problem: Only the tile 0,0 gets rendered correctly.
          SunTileScheduler sts = new SunTileScheduler(4,0,0,0);
          sts.scheduleTiles(img, new Point[]{
                    new Point(0,0)
                    , new Point(0,1)
                    , new Point(1,0)
                    , new Point(1,1)
          }, new TileComputationListener[]{
                    new TileComputationListener() {
               public void tileComputed(Object obj, TileRequest[] atilerequest, PlanarImage planarimage, int i, int j, Raster raster)
               Hello
I am using JAI to create a RenderedOp object named img and then call the TileScheduler to render me four tiles. Appearantly the scheduler tiles in 512x512, so the Point Array should render the pixels from 0,0 to 1024, 1024 spread accross four tiles.
Unfortunatly only the tile 0,0 (-> pixels 0,0,511,511) gets rendered correctly, the other three are black and take 4725 bytes each in the file system. Tile 0,0 takes ~95k
The TileComputationListener returns a Raster object that i convert into a BufferedImage:
                    BufferedImage image = new BufferedImage(raster.getWidth(),raster.getHeight(), BufferedImage.TYPE_INT_RGB);
                    image.setData(raster);After that i write the image into the file system
                    String fileName = String.format("d:/temp/tile/tiles_%s_%s.jpg", i,j);                    
                    try
                         FileOutputStream stream = new FileOutputStream(fileName);
                         JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(stream);
                         JPEGEncodeParam encodeParam = encoder.getDefaultJPEGEncodeParam(image);
                         encodeParam.setQuality(1.0, true);
                         encoder.setJPEGEncodeParam(encodeParam);
                         encoder.encode(image);
                         stream.flush();
                         stream.close();Tiles seem to be problematic because this constructor
public BufferedImage (ColorModel cm,
                          WritableRaster raster,
                          boolean isRasterPremultiplied,
                          Hashtable<?,?> properties) {rejects Rasters whose tile index is != 0,0. So it all boils down to this:
How do i convert a Raster objects into a BufferedImage?
Regards
Mark

Answer 1

                              WritableRaster wr = (WritableRaster) raster;
                              WritableRaster newRaster = wr.createWritableTranslatedChild(0,0);
                              BufferedImage image = new BufferedImage(planarimage.getColorModel(),
                                        newRaster,false,new Hashtable());