Java 操作图片进行缩放旋转翻转加水印

港控/mmm° 2024-03-26 16:35 64阅读 0赞

### 1 纯原生手写图片操作工具类 ###

import java.awt.Dimension;
    import java.awt.Graphics2D;
    import java.awt.Image;
    import java.awt.Rectangle;
    import java.awt.image.BufferedImage;
    public class RotateImageUtil {
        
        public static BufferedImage rotateImage(BufferedImage bufferedImage, int angel) {
        
            if (bufferedImage == null) {
        
                return null;
            }
            if (angel < 0) {
        
                // 将负数角度，纠正为正数角度
                angel = angel + 360;
            }
            int imageWidth = bufferedImage.getWidth(null);
            int imageHeight = bufferedImage.getHeight(null);
            // 计算重新绘制图片的尺寸
            Rectangle rectangle = calculatorRotatedSize(new Rectangle(new Dimension(imageWidth, imageHeight)), angel);
            // 获取原始图片的透明度
            int type = bufferedImage.getColorModel().getTransparency();
            BufferedImage newImage = null;
            newImage = new BufferedImage(rectangle.width, rectangle.height, type);
            Graphics2D graphics = newImage.createGraphics();
            // 平移位置
            graphics.translate((rectangle.width - imageWidth) / 2, (rectangle.height - imageHeight) / 2);
            // 旋转角度
            graphics.rotate(Math.toRadians(angel), imageWidth / 2, imageHeight / 2);
            // 绘图
            graphics.drawImage(bufferedImage, null, null);
            return newImage;
        }
        public static BufferedImage rotateImage(Image image, int angel) {
        
            if (image == null) {
        
                return null;
            }
            if (angel < 0) {
        
                // 将负数角度，纠正为正数角度
                angel = angel + 360;
            }
            int imageWidth = image.getWidth(null);
            int imageHeight = image.getHeight(null);
            Rectangle rectangle = calculatorRotatedSize(new Rectangle(new Dimension(imageWidth, imageHeight)), angel);
            BufferedImage newImage = null;
            newImage = new BufferedImage(rectangle.width, rectangle.height, BufferedImage.TYPE_INT_RGB);
            Graphics2D graphics = newImage.createGraphics();
            graphics.translate((rectangle.width - imageWidth) / 2, (rectangle.height - imageHeight) / 2);
            graphics.rotate(Math.toRadians(angel), imageWidth / 2, imageHeight / 2);
            graphics.drawImage(image, null, null);
            return newImage;
        }
        //计算旋转后的尺寸
        private static Rectangle calculatorRotatedSize(Rectangle src, int angel) {
        
            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 java.awt.Rectangle(new Dimension(des_width, des_height));
        }
    }

main方法调用

import javax.imageio.ImageIO;
    import java.awt.image.BufferedImage;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.InputStream;
    public class test {
        
        //测试一下，直接抛出异常了，小伙伴们项目中要记住用try···catch···哦
        public static void main(String[] args) throws Exception {
        
            File picture = new File("C:\\Users\\Administrator\\Desktop\\saga.png");
            BufferedImage sourceImg = ImageIO.read(new FileInputStream(picture));
            if ( sourceImg.getHeight() > sourceImg.getWidth() ) {
        
                //旋转，这里数值代表顺时针，逆时针，各位可以换其他角度玩儿玩儿
                BufferedImage rotate = RotateImageUtil.rotateImage(sourceImg, -90);
                ImageIO.write(rotate, "png", new File("D:\\", picture.getName()));
                InputStream is = new FileInputStream( new File("D:\\", picture.getName()) );
                byte[] data = new byte[is.available()];
                is.read(data);
                is.close();
            } else {
        
                System.out.println(false);
            }
        }
    }

### 2 Hutool操作图片 ###

<dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.1.0</version>
        </dependency>

操作图片示例代码：

import cn.hutool.core.img.ImgUtil;
    import cn.hutool.core.io.FileUtil;
    import javax.imageio.ImageIO;
    import java.awt.*;
    import java.awt.image.BufferedImage;
    import java.io.IOException;
    
    public class HutoolImage {
        
        public static void main(String[] args)  {
        
    
            //提供两种重载方法，按长宽缩放，按比例缩放
            ImgUtil.scale(
                    FileUtil.file("C:\\Users\\DELL\\Desktop\\animal.jpg"),
                    FileUtil.file("C:\\Users\\DELL\\Desktop\\Image\\animal_result.jpg"),
                    0.5f   //图片缩放比例
            );
            //图片按一定的尺寸裁剪
            ImgUtil.cut(
                    FileUtil.file("C:\\Users\\DELL\\Desktop\\animal.jpg"),
                    FileUtil.file("C:\\Users\\DELL\\Desktop\\Image\\animal_small.jpg"),
                    new Rectangle(200, 200, 100, 100)//裁剪的矩形区域
            );
    
            //按照行列裁剪切片
            ImgUtil.slice(FileUtil.file("C:\\Users\\DELL\\Desktop\\animal.jpg"), FileUtil.file("C:\\Users\\DELL\\Desktop\\test\\"), 10, 10);
    
            //将图片彩色转黑白色
            ImgUtil.gray(FileUtil.file("C:\\Users\\DELL\\Desktop\\animal.jpg"), FileUtil.file("C:\\Users\\DELL\\Desktop\\Image\\animal_black.jpg"));
    
            //给图片添加文字水印
            ImgUtil.pressText(//
                    FileUtil.file("C:\\Users\\DELL\\Desktop\\animal.jpg"), //
                    FileUtil.file("C:\\Users\\DELL\\Desktop\\Image\\animal_logo.jpg"), //
                    "版权所有", Color.BLUE, //文字
                    new Font("宋体", Font.BOLD, 100), //字体
                    0, //x坐标修正值。 默认在中间，偏移量相对于中间偏移
                    0, //y坐标修正值。 默认在中间，偏移量相对于中间偏移
                    0.8f//透明度：alpha 必须是范围 [0.0, 1.0] 之内（包含边界值）的一个浮点数字
            );
    
            //旋转图片180度
            BufferedImage image = null;
            try {
        
                image = (BufferedImage) ImgUtil.rotate(ImageIO.read(FileUtil.file("C:\\Users\\DELL\\Desktop\\animal.jpg")), 180);
            } catch (IOException e) {
        
                e.printStackTrace();
            }
            ImgUtil.write(image, FileUtil.file("C:\\Users\\DELL\\Desktop\\Image\\animal_tangle.jpg"));
    
            //图片水平翻转
            ImgUtil.flip(FileUtil.file("C:\\Users\\DELL\\Desktop\\animal.jpg"), FileUtil.file("C:\\Users\\DELL\\Desktop\\Image\\animal_flat.jpg"));
    
            //转换图片存储格式
            ImgUtil.convert(FileUtil.file("C:\\Users\\DELL\\Desktop\\animal.jpg"), FileUtil.file("C:\\Users\\DELL\\Desktop\\Image\\animal.png"));
    
    
        }
    }

### 3 谷歌开源框架Thumbnailator ###

Thumbnailator 是一个优秀的图片处理的Google开源Java类库。处理效果远比Java API的好。从API提供现有的图像文件和图像对象的类中简化了处理过程，两三行代码就能够从现有图片生成处理后的图片，且允许微调图片的生成方式，同时保持了需要写入的最低限度的代码量。还支持对一个目录的所有图片进行批量处理操作

支持的处理操作：图片缩放，区域裁剪，水印，旋转，保持比例。

另外值得一提的是，Thumbnailator至今仍不断更新，怎么样，感觉很有保障吧！  
Thumbnailator官网： [http://code.google.com/p/thumbnailator/][http_code.google.com_p_thumbnailator]

文章教程：[https://blog.csdn.net/qq\_37712731/article/details/118514686][https_blog.csdn.net_qq_37712731_article_details_118514686]

1、指定大小进行缩放

//size(宽度, 高度)
     
    /*
     * 若图片横比200小，高比300小，不变
     * 若图片横比200小，高比300大，高缩小到300，图片比例不变
     * 若图片横比200大，高比300小，横缩小到200，图片比例不变
     * 若图片横比200大，高比300大，图片按比例缩小，横为200或高为300
     */
    Thumbnails.of("images/a380_1280x1024.jpg")
        .size(200, 300)
        .toFile("c:/a380_200x300.jpg");
     
    Thumbnails.of("images/a380_1280x1024.jpg")
        .size(2560, 2048)
        .toFile("c:/a380_2560x2048.jpg");1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.

2、按照比例进行缩放

//scale(比例)
    Thumbnails.of("images/a380_1280x1024.jpg")
        .scale(0.25f)
        .toFile("c:/a380_25%.jpg");
     
    Thumbnails.of("images/a380_1280x1024.jpg")
        .scale(1.10f)
        .toFile("c:/a380_110%.jpg");1.2.3.4.5.6.7.8.

3、不按照比例，指定大小进行缩放

//rotate(角度),正数：顺时针负数：逆时针
    Thumbnails.of("images/a380_1280x1024.jpg")
        .size(1280,1024)
        .rotate(90)
        .toFile("c:/a380_rotate+90.jpg");
     
    Thumbnails.of("images/a380_1280x1024.jpg")
        .size(1280,1024)
        .rotate(-90)
        .toFile("c:/a380_rotate-90.jpg");1.2.3.4.5.6.7.8.9.10.

//keepAspectRatio(false)默认是按照比例缩放的
    Thumbnails.of("images/a380_1280x1024.jpg")
        .size(200,200)
        .keepAspectRatio(false)
        .toFile("c:/a380_200x200.jpg");1.2.3.4.5.

5、水印

//watermark(位置，水印图，透明度)
    Thumbnails.of("images/a380_1280x1024.jpg")
        .size(1280,1024)
        .watermark(Positions.BOTTOM_RIGHT,ImageIO.read(newFile("images/watermark.png")),0.5f)
        .outputQuality(0.8f)
        .toFile("c:/a380_watermark_bottom_right.jpg");
     
    Thumbnails.of("images/a380_1280x1024.jpg")
        .size(1280,1024)
        .watermark(Positions.CENTER,ImageIO.read(newFile("images/watermark.png")),0.5f)
        .outputQuality(0.8f)
        .toFile("c:/a380_watermark_center.jpg");1.2.3.4.5.6.7.8.9.10.11.12.

6、裁剪

//sourceRegion()
     
    //图片中心400*400的区域
    Thumbnails.of("images/a380_1280x1024.jpg")
        .sourceRegion(Positions.CENTER,400,400)
        .size(200,200)
        .keepAspectRatio(false)
        .toFile("c:/a380_region_center.jpg");
     
    //图片右下400*400的区域
    Thumbnails.of("images/a380_1280x1024.jpg")
        .sourceRegion(Positions.BOTTOM_RIGHT,400,400)
        .size(200,200)
        .keepAspectRatio(false)
        .toFile("c:/a380_region_bootom_right.jpg");
     
    //指定坐标
    Thumbnails.of("images/a380_1280x1024.jpg")
        .sourceRegion(600,500,400,400)
        .size(200,200)
        .keepAspectRatio(false)
        .toFile("c:/a380_region_coord.jpg");1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.18.19.20.21.22.

7、转化图像格式

//outputFormat(图像格式)
    Thumbnails.of("images/a380_1280x1024.jpg")
        .size(1280,1024)
        .outputFormat("png")
        .toFile("c:/a380_1280x1024.png");
     
    Thumbnails.of("images/a380_1280x1024.jpg")
        .size(1280,1024)
        .outputFormat("gif")
        .toFile("c:/a380_1280x1024.gif");1.2.3.4.5.6.7.8.9.10.

8、输出到OutputStream

//toOutputStream(流对象)
    OutputStreamos=newFileOutputStream("c:/a380_1280x1024_OutputStream.png");
    Thumbnails.of("images/a380_1280x1024.jpg")
        .size(1280,1024)
        .toOutputStream(os);1.2.3.4.5.

9、输出到BufferedImage

//asBufferedImage()返回BufferedImage
    BufferedImagethumbnail=Thumbnails.of("images/a380_1280x1024.jpg")
        .size(1280,1024)
        .asBufferedImage();
    ImageIO.write(thumbnail,"jpg",newFile("c:/a380_1280x1024_BufferedImage.jpg"));

### 4 总结 ###

谷歌开源框架处理图片实测性能较差，用起来比较方便，建议用Hutool因为只是对awt做的封装不用自己写，性能也高。

原文地址：[https://blog.csdn.net/ZGL\_cyy/article/details/126680559][https_blog.csdn.net_ZGL_cyy_article_details_126680559]

[http_code.google.com_p_thumbnailator]: http://code.google.com/p/thumbnailator/
[https_blog.csdn.net_qq_37712731_article_details_118514686]: https://blog.csdn.net/qq_37712731/article/details/118514686
[https_blog.csdn.net_ZGL_cyy_article_details_126680559]: https://blog.csdn.net/ZGL_cyy/article/details/126680559