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; }