java图片旋转

来源：互联网发布：midi制作软件mac 编辑：程序博客网时间：2024/06/16 08:10
转载：http://blog.csdn.net/heliang7/article/details/1088845
java实现图片旋转任意角度
下面是核心代码：
import java.awt.Dimension;  import java.awt.Graphics2D;  import java.awt.Image;  import java.awt.Rectangle;  import java.awt.image.BufferedImage;  import java.io.File;import java.io.IOException;import javax.imageio.ImageIO;/** * 图片旋转工具 * @author Bob * */public class RotateImage {  public  BufferedImage Rotate(Image src, int angle) {  int src_width = src.getWidth(null);  int src_height = src.getHeight(null);  Rectangle rect_des = CalcRotatedSize(new Rectangle(new Dimension(src_width, src_height)), angle);  BufferedImage res = null;  res = new BufferedImage(rect_des.width, rect_des.height, BufferedImage.TYPE_INT_RGB);  Graphics2D g2 = res.createGraphics();  //将 Graphics2D 上下文的原点平移到当前坐标系中的点 (x, y)g2.translate((rect_des.width - src_width) / 2, (rect_des.height - src_height) / 2);  //将当前的 Graphics2D Transform 与平移后的旋转转换连接g2.rotate(Math.toRadians(angle), src_width / 2, src_height / 2);  g2.drawImage(src, null, null);  g2.dispose();return res;  }  /** * 计算图片的新大小 * @param src 图片 * @param angle 角度 * @return  */public  Rectangle CalcRotatedSize(Rectangle src, int angle) {  if ((angle >= 90) && (angle / 90 % 2 == 1)) {int temp = src.height;src.height = src.width;src.width = temp;angle = angle % 90;}//根据图片高宽求出旋转半径   a的平方+b的平方=c的平方   是四边形的对角线长度/2    为旋转圆的半径double r = Math.sqrt(src.height * src.height + src.width * src.width)/2; double len = 2 * Math.sin(Math.toRadians(angle) / 2) * r;  double angle_alpha = (Math.PI - Math.toRadians(angle)) / 2;  double angle_dalta_width = Math.atan((double) src.height / src.width);  double angle_dalta_height = Math.atan((double) src.width / src.height);  int len_dalta_width = (int) (len * Math.cos(Math.PI - angle_alpha - angle_dalta_width));  int len_dalta_height = (int) (len * Math.cos(Math.PI - angle_alpha - angle_dalta_height));  int des_width = src.width + len_dalta_width * 2;  int des_height = src.height + len_dalta_height * 2;  return new Rectangle(new Dimension(des_width, des_height));  }  public static void main(String[] args) {try {BufferedImage src = ImageIO.read(new File("E:/A.png"));  //旋转20度BufferedImage des = new RotateImage().Rotate(src, 20);  //保存到本地ImageIO.write(des, "png", new File("e:/A2223.png"));} catch (IOException e) {e.printStackTrace();}}}
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