// 這里是直接根據url讀取圖片
    public static BufferedImage getBufferedImage(String  imgUrl) throws MalformedURLException {
        URL url = new URL(imgUrl);
        ImageIcon icon = new ImageIcon(url);
        Image image = icon.getImage();
 
        // 如果是從本地加載，就用這種方式，沒親自測試過
        // Image src=Toolkit.getDefaultToolkit().getImage(filePath);
 
        // This code ensures that all the pixels in the image are loaded
        BufferedImage bimage = null;
        GraphicsEnvironment ge = GraphicsEnvironment
                .getLocalGraphicsEnvironment();
        try {
            int transparency = Transparency.OPAQUE;
            GraphicsDevice gs = ge.getDefaultScreenDevice();
            GraphicsConfiguration gc = gs.getDefaultConfiguration();
            bimage = gc.createCompatibleImage(image.getWidth(null),
                    image.getHeight(null), transparency);
        } catch (HeadlessException e) {
            // The system does not have a screen
        }
        if (bimage == null) {
            // Create a buffered image using the default color model
            int type = BufferedImage.TYPE_INT_RGB;
            bimage = new BufferedImage(image.getWidth(null),
                    image.getHeight(null), type);
        }
        // Copy image to buffered image
        Graphics g = bimage.createGraphics();
        // Paint the image onto the buffered image
        g.drawImage(image, 0, 0, null);
        g.dispose();
        return bimage;
    }

 bi = ImageIO.read(inStream);

bi =  getBufferedImage(inFile.getPath());