java: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;
    }