// To create a buffered image, see Creating a Buffered Image

// en the image by 30%
float scaleFactor = 1.3f;
RescaleOp op = new RescaleOp(scaleFactor, 0, null);
bufferedImage = op.filter(bufferedImage, null);

// Darken the image by 10%
scaleFactor = .9f;
op = new RescaleOp(scaleFactor, 0, null);
bufferedImage = op.filter(bufferedImage, null);