ImageLayout imageLayout = new ImageLayout();
imageLayout.setSampleModel(sm);
imageLayout.setColorModel(cm);
RenderingHints renderingHints = new RenderingHints(null);
renderingHints.clear();
renderingHints.put(JAI.KEY_IMAGE_LAYOUT, imageLayout);
// Perform the band combine operation.
srcImg = JAI.create("bandcombine", pb, renderingHints);