java实现图片任意角度旋转

/**   * 图像旋转   * @param src   * @param angel   * @return*/  public static BufferedImage Rotate(Image src, double angel) {    int src_width = src.getWidth(null);    int src_height = src.getHeight(null);    // calculate the new image size    Rectangle rect_des = CalcRotatedSize(new Rectangle(new Dimension(        src_width, src_height)), angel);     BufferedImage res = null;    res = new BufferedImage(rect_des.width, rect_des.height,        BufferedImage.TYPE_3BYTE_BGR);    Graphics2D g2 = res.createGraphics();    // transform    g2.translate((rect_des.width - src_width) / 2,        (rect_des.height - src_height) / 2);    g2.rotate(Math.toRadians(angel), src_width / 2, src_height / 2);     g2.drawImage(src, null, null);    return res;  }   public static Rectangle CalcRotatedSize(Rectangle src, double angel) {    // if angel is greater than 90 degree, we need to do some conversion    if (angel >= 90) {      if(angel / 90 % 2 == 1){        int temp = src.height;        src.height = src.width;        src.width = temp;      }      angel = angel % 90;    }     double r = Math.sqrt(src.height * src.height + src.width * src.width) / 2;    double len = 2 * Math.sin(Math.toRadians(angel) / 2) * r;    double angel_alpha = (Math.PI - Math.toRadians(angel)) / 2;    double angel_dalta_width = Math.atan((double) src.height / src.width);    double angel_dalta_height = Math.atan((double) src.width / src.height);     int len_dalta_width = (int) (len * Math.cos(Math.PI - angel_alpha        - angel_dalta_width));    len_dalta_width=len_dalta_width>0?len_dalta_width:-len_dalta_width;     int len_dalta_height = (int) (len * Math.cos(Math.PI - angel_alpha        - angel_dalta_height));    len_dalta_height=len_dalta_height>0?len_dalta_height:-len_dalta_height;     int des_width = src.width + len_dalta_width * 2;    int des_height = src.height + len_dalta_height * 2;    des_width=des_width>0?des_width:-des_width;    des_height=des_height>0?des_height:-des_height;    return new java.awt.Rectangle(new Dimension(des_width, des_height));}

 /**   * opencv实现图片旋转   * @param splitImage   * @param angle   * @return*/  public static Mat rotate3(Mat splitImage, double angle)  {    double thera = angle * Math.PI / 180;    double a = Math.sin(thera);    double b = Math.cos(thera);     int wsrc = splitImage.width();    int hsrc = splitImage.height();     int wdst = (int) (hsrc * Math.abs(a) + wsrc * Math.abs(b));    int hdst = (int) (wsrc * Math.abs(a) + hsrc * Math.abs(b));    Mat imgDst = new Mat(hdst, wdst, splitImage.type());     Point pt = new Point(splitImage.cols() / 2, splitImage.rows() / 2);    // 获取仿射变换矩阵    Mat affineTrans = Imgproc.getRotationMatrix2D(pt, angle, 1.0);     System.out.println(affineTrans.dump());    // 改变变换矩阵第三列的值    affineTrans.put(0, 2, affineTrans.get(0, 2)[0] + (wdst - wsrc) / 2);    affineTrans.put(1, 2, affineTrans.get(1, 2)[0] + (hdst - hsrc) / 2);     Imgproc.warpAffine(splitImage, imgDst, affineTrans, imgDst.size(),        Imgproc.INTER_CUBIC | Imgproc.WARP_FILL_OUTLIERS);    return imgDst;}