public PixelGrabber(Image img, int x, int y, int w, int h, boolean forceRGB)
public PixelGrabber(Image img, int x, int y, int w, int h, int pix[], int off, int scansize)
  public PixelGrabber(Image img,		      int x, int y,		      int w, int h,		      boolean forceRGB)  {		this.ip = img.getSource();    this.x = x;    this.y = y;    width = w;    height = h;    // If width or height is negative, postpone pixel buffer    // initialization until setDimensions is called back by ip.    if (width >= 0 && height >= 0)      {	int_pixel_buffer = new int[width * height];	byte_pixel_buffer = new byte[width * height];      }    this.forceRGB = forceRGB;	}