Rails Against The Machine

Need to change alpha transparency independently of colour so changing from index color to direct.
More bitmask fun

package services;

import java.awt.Point;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;
import java.awt.image.DirectColorModel;
import java.awt.image.SampleModel;
import java.awt.image.WritableRaster;

public class ImageFactory
{

    private static int width = 255;
    private static int height = 255;

    public static BufferedImage Image()
    {
        // This creates an RGBA colormodel... I think.
        DirectColorModel colormodel = new DirectColorModel(32, 0xff000000, 0xff0000, 0xff00, 0xff);
        int[] pixels = generatePixels(width, height);
        SampleModel sample = colormodel.createCompatibleSampleModel(width, height);
        DataBufferInt data = new DataBufferInt(pixels, width * height);
        WritableRaster raster = WritableRaster.createWritableRaster(sample, data, new Point(0, 0));
        return new BufferedImage(colormodel, raster, false, null);
    }

    private static int[] generatePixels(int w, int h)
    {
        int[] pixData = new int[width * height];
        int i = 0;
        for (int y = 0; y < height; y++) {
            int red = (y * 255) / (height - 1);
            for (int x = 0; x < width; x++) {
                int green = (x * 255) / (width - 1);
                int blue = 128;
                int alpha = Math.max(0,x-y);
                pixData[i++] = (alpha << 32) | (red << 24) |
                        (green << 16) | (blue << 8);
            }
        }
        return pixData;
    }
}