java中如何使用BufferedImage判断图像通道顺序并转RGB/BGR

 /**
   * @param image
   * @param bandOffset 用于判断通道顺序
   * @return
   */
  private static boolean equalBandOffsetWith3Byte(BufferedImage image,int[] bandOffset){
    if(image.getType()==BufferedImage.TYPE_3BYTE_BGR){
      if(image.getData().getSampleModel() instanceof ComponentSampleModel){
        ComponentSampleModel sampleModel = (ComponentSampleModel)image.getData().getSampleModel();
        if(Arrays.equals(sampleModel.getBandOffsets(), bandOffset)){
          return true;
        }
      }
    }
    return false;    
  }
  /**
   * 判断图像是否为BGR格式
   * @return 
   */
  public static boolean isBGR3Byte(BufferedImage image){
    return equalBandOffsetWith3Byte(image,new int[]{0, 1, 2});
  }
  /**
   * 判断图像是否为RGB格式
   * @return 
   */
  public static boolean isRGB3Byte(BufferedImage image){
    return equalBandOffsetWith3Byte(image,new int[]{2, 1, 0});
  }
  /**
   * 对图像解码返回RGB格式矩阵数据
   * @param image
   * @return 
   */
  public static byte[] getMatrixRGB(BufferedImage image) {
    if(null==image)
      throw new NullPointerException();
    byte[] matrixRGB;
    if(isRGB3Byte(image)){
      matrixRGB= (byte[]) image.getData().getDataElements(0, 0, image.getWidth(), image.getHeight(), null);
    }else{
      // 转RGB格式
      BufferedImage rgbImage = new BufferedImage(image.getWidth(), image.getHeight(), 
          BufferedImage.TYPE_3BYTE_BGR);
      new ColorConvertOp(ColorSpace.getInstance(ColorSpace.CS_sRGB), null).filter(image, rgbImage);
      matrixRGB= (byte[]) rgbImage.getData().getDataElements(0, 0, image.getWidth(), image.getHeight(), null);
    } 
    return matrixRGB;
  }
  /**
   * 对图像解码返回BGR格式矩阵数据
   * @param image
   * @return
   */
  public static byte[] getMatrixBGR(BufferedImage image){
    if(null==image)
      throw new NullPointerException();
    byte[] matrixBGR;
    if(isBGR3Byte(image)){
      matrixBGR= (byte[]) image.getData().getDataElements(0, 0, image.getWidth(), image.getHeight(), null);
    }else{     
      // ARGB格式图像数据
      int intrgb[]=image.getRGB(0, 0, image.getWidth(), image.getHeight(), null, 0, image.getWidth());
      matrixBGR=new byte[image.getWidth() * image.getHeight()*3];
      // ARGB转BGR格式
      for(int i=0,j=0;i<intrgb.length;++i,j+=3){
        matrixBGR[j]=(byte) (intrgb[i]&0xff);
        matrixBGR[j+1]=(byte) ((intrgb[i]>>8)&0xff);
        matrixBGR[j+2]=(byte) ((intrgb[i]>>16)&0xff);
      }
    } 
    return matrixBGR;
  }