java实现读取一张图片给这张图片整体颜色加深

public static void resize(String filePath, int height, int width, boolean bb) {
        try {
            double ratio = 0; //缩放比例    
            File f = new File(filePath);   
            BufferedImage bi = ImageIO.read(f);   
            Image itemp = bi.getScaledInstance(width, height, BufferedImage.SCALE_SMOOTH);   
            //计算比例   
            if ((bi.getHeight() > height) || (bi.getWidth() > width)) {   
                if (bi.getHeight() > bi.getWidth()) {   
                    ratio = (new Integer(height)).doubleValue() / bi.getHeight();   
                } else {   
                    ratio = (new Integer(width)).doubleValue() / bi.getWidth();   
                }   
                AffineTransformOp op = new AffineTransformOp(AffineTransform.getScaleInstance(ratio, ratio), null);   
                itemp = op.filter(bi, null);   
            }   
            if (bb) {   
                BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);   
                Graphics2D g = image.createGraphics();   
                g.setColor(Color.white);   
                g.fillRect(0, 0, width, height);   
                if (width == itemp.getWidth(null))   
                    g.drawImage(itemp, 0, (height - itemp.getHeight(null)) / 2, itemp.getWidth(null), itemp.getHeight(null), Color.white, null);   
                else  
                    g.drawImage(itemp, (width - itemp.getWidth(null)) / 2, 0, itemp.getWidth(null), itemp.getHeight(null), Color.white, null);   
                g.dispose();   
                itemp = image;   
            }
            ImageIO.write((BufferedImage) itemp, "jpg", f);   
        } catch (IOException e) {
            e.printStackTrace();
        }
    }