Java实现图片无损任意角度旋转

2020-06-08 15:52:41 浏览数 (1)

在做项目的时候遇到一个业务需要对图片进行旋转,于是找到一个工具类,亲测有效;在此与大家共享,需要用时可以直接用哈! 一、旋转工具类代码:

代码语言:javascript复制
package zh.test.utils;
 
import java.awt.*;
import java.awt.image.BufferedImage;
 
/**
 * 图片旋转工具类
 */
public class RotateImage {
 
    /**
     * 对图片进行旋转
     *
     * @param src   被旋转图片
     * @param angel 旋转角度
     * @return 旋转后的图片
     */
    public static BufferedImage Rotate(Image src, int angel) {
        int src_width = src.getWidth(null);
        int src_height = src.getHeight(null);
        // 计算旋转后图片的尺寸
        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_INT_RGB);
        Graphics2D g2 = res.createGraphics();
        // 进行转换
        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;
    }
 
    /**
     * 计算旋转后的图片
     *
     * @param src   被旋转的图片
     * @param angel 旋转角度
     * @return 旋转后的图片
     */
    public static Rectangle CalcRotatedSize(Rectangle src, int angel) {
        // 如果旋转的角度大于90度做相应的转换
        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));
        int len_dalta_height = (int) (len * Math.cos(Math.PI - angel_alpha
                - angel_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));
    }
}

二、调用工具类的代码:

代码语言:javascript复制
package zh.test.controller;
 
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import zh.test.utils.RotateImage;
 
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
 
/**
 * 测试图片旋转
 */
@RestController
@RequestMapping(value = "/test")
public class TestController {
 
    @RequestMapping(method = RequestMethod.POST)
    public void testImgRotate(MultipartFile multipartFile) throws Exception {
        BufferedImage src = ImageIO.read(multipartFile.getInputStream());
        //顺时针旋转90度
        BufferedImage des1 = RotateImage.Rotate(src, 90);
        ImageIO.write(des1, "jpg", new File("e:/90.jpg"));
        //顺时针旋转180度
        BufferedImage des2 = RotateImage.Rotate(src, 180);
        ImageIO.write(des2, "jpg", new File("c:/180.jpg"));
        //顺时针旋转270度
        BufferedImage des3 = RotateImage.Rotate(src, 270);
        ImageIO.write(des3, "jpg", new File("c:/270.jpg"));
 
    }
 
}

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