Java操作图片大全

素颜马尾好姑娘i 2024-04-01 13:41 66阅读 0赞

#### 目录 ####

*  前言
 *  一、获取系统支持图片格式
 *  二、生成自定义图片
 *  三、获取图片格式
 *  四、图片裁剪
 *  五、图片压缩
 *  六、图片水印
 *  七、Thumbnails工具类

## 前言 ##

> **本文主要使用Java对图片各种操作进行处理。**

## 一、获取系统支持图片格式 ##

代码：

System.out.println(Arrays.asList(ImageIO.getReaderFormatNames()));
    System.out.println(Arrays.asList(ImageIO.getReaderFileSuffixes()));
    System.out.println(Arrays.asList(ImageIO.getReaderMIMETypes()));
    
    String[] writerFormatName = ImageIO.getWriterFormatNames();
    String[] writerSuffixName = ImageIO.getWriterFileSuffixes();
    String[] writerMIMEType = ImageIO.getWriterMIMETypes();

输出：

[JPG, jpg, tiff, pcx, PCX, bmp, BMP, gif, GIF, WBMP, png, PNG, raw, RAW, JPEG, pnm, PNM, tif, TIF, TIFF, wbmp, jpeg]
    [, jpg, tiff, pcx, bmp, gif, png, ppm, tif, pgm, wbmp, jpeg, pbm]
    [, image/vnd.wap.wbmp, image/png, image/jpeg, image/x-portable-graymap, image/pcx, image/bmp, image/gif, image/x-windows-pcx, image/x-windows-bmp, image/x-pc-paintbrush, image/x-pcx, image/x-bmp, image/x-png, image/x-portable-bitmap, image/x-portable-pixmap, image/tiff, image/x-portable-anymap]

## 二、生成自定义图片 ##

代码：

@SneakyThrows
    public static void main(String[] args) {
        
        BufferedImage bufferedImage = new BufferedImage(400, 400, BufferedImage.TYPE_INT_BGR);
        Graphics g = bufferedImage.getGraphics();
        try {
        
            g.fillRect(20, 40, 400, 400);
            g.setColor(new Color(120, 120, 120));
            g.setFont(new Font("隶书", Font.BOLD, 28));
            g.drawString("自定义图片", 200, 200);
            ImageIO.write(bufferedImage, "jpg", new File("D:/test.jpg"));
        } finally {
        
            g.dispose();//释放画笔
        }
    }

输出：  
![请添加图片描述][3c1f7c70af2a4b7ea4a0cf24a7d8e110.jpeg]

## 三、获取图片格式 ##

代码：

public static String getImageFormatName(File file) throws IOException {
        
         String formatName = null;
         ImageInputStream iis = ImageIO.createImageInputStream(file);
         Iterator<ImageReader> imageReader = ImageIO.getImageReaders(iis);
         if (imageReader.hasNext()) {
        
             ImageReader reader = imageReader.next();
             formatName = reader.getFormatName();
         }
         return formatName;
     }

## 四、图片裁剪 ##

public static String cutImage(String sourcePath, String targetPath, int x, int y, int width, int height) throws IOException {
        
            File file = new File(sourcePath);
            if (!file.exists()) {
        
                throw new IOException("not found the image：" + sourcePath);
            }
            if (null == targetPath || targetPath.isEmpty()) {
        
                targetPath = sourcePath;
            }
    
            String formatName = getImageFormatName(file);
            if (null == formatName) {
        
                return targetPath;
            }
            formatName = formatName.toLowerCase();
    
            // 防止图片后缀与图片本身类型不一致的情况
            String pathPrefix = getPathWithoutSuffix(targetPath);
            targetPath = pathPrefix + formatName;
    
            // GIF需要特殊处理
            if (IMAGE_FORMAT.GIF.getValue() == formatName) {
        
                GifDecoder decoder = new GifDecoder();
                int status = decoder.read(sourcePath);
                if (status != GifDecoder.STATUS_OK) {
        
                    throw new IOException("read image " + sourcePath + " error!");
                }
    
                AnimatedGifEncoder encoder = new AnimatedGifEncoder();
                encoder.start(targetPath);
                encoder.setRepeat(decoder.getLoopCount());
                for (int i = 0; i < decoder.getFrameCount(); i++) {
        
                    encoder.setDelay(decoder.getDelay(i));
                    BufferedImage childImage = decoder.getFrame(i);
                    BufferedImage image = childImage.getSubimage(x, y, width, height);
                    encoder.addFrame(image);
                }
                encoder.finish();
            } else {
        
                BufferedImage image = ImageIO.read(file);
                image = image.getSubimage(x, y, width, height);
                ImageIO.write(image, formatName, new File(targetPath));
            }
            return targetPath;
        }

![请添加图片描述][ddfe20f23d9441909b66e068770885b3.jpeg]

## 五、图片压缩 ##

public static String zoom(String sourcePath, String targetPath, int width, int height) throws IOException {
        
            File file = new File(sourcePath);
            if (!file.exists()) {
        
                throw new IOException("not found the image ：" + sourcePath);
            }
            if (null == targetPath || targetPath.isEmpty()) {
        
                targetPath = sourcePath;
            }
            String formatName = getImageFormatName(file);
            if (null == formatName) {
        
                return targetPath;
            }
            formatName = formatName.toLowerCase();
            String pathPrefix = getPathWithoutSuffix(targetPath);
            targetPath = pathPrefix + formatName;
    
            // GIF处理
            if (IMAGE_FORMAT.GIF.getValue() == formatName) {
        
                GifDecoder decoder = new GifDecoder();
                int status = decoder.read(sourcePath);
                if (status != GifDecoder.STATUS_OK) {
        
                    throw new IOException("read image " + sourcePath + " error!");
                }
                AnimatedGifEncoder encoder = new AnimatedGifEncoder();
                encoder.start(targetPath);
                encoder.setRepeat(decoder.getLoopCount());
                for (int i = 0; i < decoder.getFrameCount(); i++) {
        
                    encoder.setDelay(decoder.getDelay(i));
                    BufferedImage image = zoom(decoder.getFrame(i), width, height);
                    encoder.addFrame(image);
                }
                encoder.finish();
            } else {
        
                BufferedImage image = ImageIO.read(file);
                BufferedImage zoomImage = zoom(image, width, height);
                ImageIO.write(zoomImage, formatName, new File(targetPath));
            }
            return targetPath;
        }

![请添加图片描述][e8fbed1608f945e2bf9187517329200f.png]

## 六、图片水印 ##

private static void waterMark(Image srcImg, String path) throws IOException {
        
            int srcImgWidth = srcImg.getWidth(null);
            int srcImgHeight = srcImg.getHeight(null);
    /*
            //网络图片
            URL url = new URL("url");
            //将URL对象输入流转化为图片对象 (url.openStream()方法，获得一个输入流)
            Image srcImg = ImageIO.read(url.openStream());
            //获取图片的宽
            int srcImgWidth = srcImg.getWidth(null);
            //获取图片的高
            int srcImgHeight = srcImg.getHeight(null);
            System.out.println("图片的宽:"+srcImgWidth);
            System.out.println("图片的高:"+srcImgHeight);
    */
            BufferedImage bufImg = new BufferedImage(srcImgWidth, srcImgHeight, BufferedImage.TYPE_INT_RGB);
            // 加水印
            //创建画笔
            Graphics2D g = bufImg.createGraphics();
            //绘制原始图片
            g.drawImage(srcImg, 0, 0, srcImgWidth, srcImgHeight, null);
    /*
            //文字水印
            //根据图片的背景设置水印颜色
            g.setColor(new Color(255, 255, 255, 128));
            //设置字体  画笔字体样式为微软雅黑，加粗，文字大小为60pt
            g.setFont(new Font("微软雅黑", Font.BOLD, 60));
            String waterMarkContent = "自定义水印";
            //设置水印的坐标(为原图片中间位置)
            int x = srcImgWidth / 2;
            int y = srcImgHeight / 2;
            //画出水印 第一个参数是水印内容，第二个参数是x轴坐标，第三个参数是y轴坐标
            g.drawString(waterMarkContent, x, y);
            g.dispose();*/
    
            //图片水印
            // 水印文件
            String waterMarkImage = "D:/print.jpg";
            Image srcWaterMark = ImageIO.read(new File(waterMarkImage));
            //获取水印图片的宽度
            int widthWaterMark = srcWaterMark.getWidth(null);
            //获取水印图片的高度
            int heightWaterMark = srcWaterMark.getHeight(null);
            //设置 alpha 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
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 0.9f));
            //绘制水印图片
            g.drawImage(srcWaterMark, (srcImgWidth - widthWaterMark) / 10,
                    (srcImgHeight - heightWaterMark) / 10, widthWaterMark, heightWaterMark, null);
            // 水印文件结束
            g.dispose();
    
            //文件输出地址
            String tarImgPath = path;
            // 输出图片
            FileOutputStream outImgStream = new FileOutputStream(tarImgPath);
            ImageIO.write(bufImg, "png", outImgStream);
            outImgStream.flush();
            outImgStream.close();
        }

## 七、Thumbnails工具类 ##

> 通过以上对图片的各种操作，还是需要对流进行转化，那是不是已经有成型的工具类了呢？对，Thumbnails工具类就能对以上各种情况处理。

主要有以下功能处理：

> 旋转
> 
> 水印
> 
> 裁剪
> 
> 指定大小进行缩放
> 
> 按照比例进行缩放
> 
> 不按照比例，指定大小进行缩放
> 
> 转化图片格式
> 
> 输出到OutputStream
> 
> 输出到BufferedImage

代码示例如下：

依赖

<dependency>
            <groupId>net.coobird</groupId>
            <artifactId>thumbnailator</artifactId>
            <version>0.4.17</version>
    </dependency>

代码

@SneakyThrows
        public static void main(String[] args) {
        
            //指定大小进行缩放
            Thumbnails.of("D:/test.jpg").size(100, 100).toFile("D:/test.jpg.jpg");
    
            //按照比例进行缩放
            // scale 图片的压缩比例 值在0-1之间，1f就是原图，0.5就是原图的一半大小
            // outputQuality 图片压缩的质量 值在0-1 之间，越接近1质量越好，越接近0 质量越差
            Thumbnails.of("D:/test.jpg").scale(0.75f).outputQuality(0.8f).toFile("D:/test.jpg");
    
            //不按照比例，指定大小进行缩放 100 keepAspectRatio(false) 默认是按照比例缩放的
            Thumbnails.of("D:/test.jpg").size(100, 100).keepAspectRatio(false).toFile("D:/test.jpg");
    
            //旋转  rotate(角度),正数：顺时针 负数：逆时针
            Thumbnails.of("D:/test.jpg").size(1024, 1024).rotate(90).toFile("C:/image+90.jpg");
    
            //水印 watermark(位置，水印图，透明度)
            Thumbnails.of("D:/test.jpg").size(1024, 1024)
                    .watermark(Positions.BOTTOM_RIGHT, ImageIO.read(new File("水印地址")), 0.5f)
                    .outputQuality(0.4f).toFile("输出地址");
    
            //裁剪
            Thumbnails.of("D:/test.jpg").sourceRegion(Positions.CENTER, 400, 400).size(200, 200).keepAspectRatio(false)
                    .toFile("输出地址");
    
            //转化图片格式
            Thumbnails.of("D:/test.jpg").size(666, 666).outputFormat("png").toFile("D:/test.png");
    
            // 输出到OutputStream
            OutputStream os = new FileOutputStream("D:/test.jpg");
            Thumbnails.of("test.jpg").size(666, 666).toOutputStream(os);
    
            //输出到BufferedImage
            BufferedImage thumbnail = Thumbnails.of("D:/test.jpg").size(666, 666).asBufferedImage();
            ImageIO.write(thumbnail, "jpg", new File("test.jpg"));
        }

![在这里插入图片描述][5e1b731011d04f1b8b5bb34319048090.png]

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