Java调用opencv实现图片去水印

Java调用opencv实现图片去水印

最近项目中遇到个需求，图片去水印下载，由于上传时并未保存原图url，查找了相关资料，基本上都是通过设置RGB色值去水印，测试过后效果并不理想，会将图片中颜色跟RGB色值相同的也给去掉，在朋友的推荐下，使用了opecv这款开源软件，而Java调用opencv的例子很少，opencv官网上也没有java相关的api操作文档，期间踩了不少坑，最终在windows上测试通过，并在linux上也运行成功了（linux上效果更好），仅在这里记录下相关步骤，希望后续遇到同问题的人少走弯路。

环境安装配置

opencv官网链接：https://opencv.org/releases/
这里以opencv-4.5.1为例。

1. windows环境，官网上选择windows版本下载安装即可，如下所示；

2. linux环境，官网上选择sources下载zip压缩包，如下所示；

• 1）将下载好的压缩包放置到linux服务器下（以unbuntu为例），存放位置可自行指定，如 /usr/local/enviroment/opencv，执行解压命令unzip opencv-4.5.1.zip
• 2）进入解压好的目录，新建一个build目录，进入build目录下；

cd opencv-4.5.1
mkdir build
cd build

• 3）下载cmake，并安装相关联的包；

apt install cmake  
sudo apt-get install cmake  
sudo apt-get install build-essential libgtk2.0-dev libavcodec-dev libavformat-dev libjpeg.dev libtiff4.dev libswscale-dev libjasper-dev

• 4）用cmake生成java的jar；

cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -DBUILD_TESTS=OFF ..

• 5）结束后输入如下口令；

make -j8
sudo make install

• 6）安装结果；

build/bin下有opencv-451.jar、build/lib下有libopencv_java451.so文件，表示安装成功

IDEA下开发配置

1. 通过maven命令将opencv-451.jar打包至本地maven仓库；

安装指定文件到本地仓库命令：mvn install:install-file
-Dfile=       : 设置该jar包文件所在的路径与文件名
-DgroupId=       : 设置上传到仓库的包名
-DartifactId= : 设置该包所属的模块名
-Dversion=1.0.0           : 设置该包的版本号
-Dpackaging=jar           : 设置该包的类型(很显然jar包)
如：mvn install:install-file -Dfile=D:/opencv/opencv-451.jar -DgroupId=org.opencv -DartifactId=opencv -Dversion=4.5.1 -Dpackaging=jar

2. pom文件中添加maven依赖；

<!-- opencv -->
<dependency>
    <groupId>org.opencv</groupId>
    <artifactId>opencv</artifactId>
    <version>4.5.1</version>
</dependency>

3. opencv动态库配置；

通过在application.yml文件中配置动态库路径，并增加配置类，完成配置。
1）application.yml配置如下；

opencv:
  lib:
  	# linux
    #path: /usr/local/environment/opencv/opencv-4.5.1/build/lib/libopencv_java451.so
    #windows
	path: D:/opencv/opencv/build/java/x64/opencv_java451.dll

2）配置类如下：

/**
  * opencv动态库配置
  * @author wangjiajin
  * @date 2021/3/2
  * @desc
 */
@Configuration
@ConfigurationProperties(prefix = "opencv.lib")
public class OpenCvLibConfig {

    @Value("${opencv.lib.path}")
    private String path;

    @PostConstruct
    public void init() {
        System.load(path);
    }
}

测试案例

1. 图片工具类

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.time.LocalDateTime;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

/**
 * 图片工具类
 * @author wangjiajin
 * @date 2021/2/23
 * @desc
 */
public class ImageUtils {

	public static void addWaterMark(String srcImgPath, String waterMarkContent, String waterImgPath) {
		try {
			// 读取原图片信息
			File srcImgFile = new File(srcImgPath);//得到文件
			Image srcImg = ImageIO.read(srcImgFile);//文件转化为图片
			int srcImgWidth = srcImg.getWidth(null);//获取图片的宽
			int srcImgHeight = srcImg.getHeight(null);//获取图片的高
			int fontSize = (srcImgWidth - 20) / waterMarkContent.length();
			Font font = new Font("宋体", Font.PLAIN, fontSize);
			// 加水印
			BufferedImage bufImg = new BufferedImage(srcImgWidth, srcImgHeight, BufferedImage.TYPE_INT_RGB);
			Graphics2D g = bufImg.createGraphics();
			g.drawImage(srcImg, 0, 0, srcImgWidth, srcImgHeight, null);
			g.setColor(Color.white); //根据图片的背景设置水印颜色
			g.setFont(font);              //设置字体
			g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 0.4f));
			//设置水印的坐标
			int x = 10;
			int y = (srcImgHeight) / 2;
			g.drawString(waterMarkContent, x, y);  //画出水印
			g.dispose();
			// 输出图片
			FileOutputStream outImgStream = new FileOutputStream(waterImgPath);
			ImageIO.write(bufImg, "jpg", outImgStream);
			outImgStream.flush();
			outImgStream.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static void getMask(String path, String waterMarkContent, String maskPath) {
		try {
			Image originImg = ImageIO.read(new File(path));
			int width = originImg.getWidth(null);
			int height = originImg.getHeight(null);
			int fontSize = (width - 20) / waterMarkContent.length();
			Font font = new Font("宋体", Font.PLAIN, fontSize);
			BufferedImage bufImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
			Graphics2D g = bufImg.createGraphics();
			g.setBackground(Color.BLACK);
			g.clearRect(0, 0, width, height);
			g.setColor(Color.white);
			g.setFont(font);
			g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 0.4f));
			//设置水印的坐标
			int x = 10;
			int y = (height) / 2;
			g.drawString(waterMarkContent, x, y);  //画出水印
			g.dispose();
			// 输出图片
			FileOutputStream outImgStream = new FileOutputStream(maskPath);
			ImageIO.write(bufImg, "jpg", outImgStream);
			outImgStream.flush();
			outImgStream.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * 给定一组url，将此集合地址下对应的资源下载到浏览器
	 *
	 * @param urls url地址的集合
	 * @throws IOException
	 */
	public static void downloadPic(java.util.List<String> urls, HttpServletResponse response) throws Exception {
		ZipOutputStream zos = new ZipOutputStream(response.getOutputStream());
		try {
			//文件的名称
			String downloadFilename = "图片.zip";
			//转换中文否则可能会产生乱码
			downloadFilename = URLEncoder.encode(downloadFilename, "UTF-8");
			//指明response的返回对象是文件流
			response.setContentType("application/octet-stream;charset=UTF-8");
			//设置在下载框默认显示的文件名
			response.setHeader("Content-Disposition","attachment;filename="+downloadFilename);

			for (String url : urls) {
				String imgName = LocalDateTime.now().toString();
				String suffix = url.substring(url.lastIndexOf("."));
				zos.putNextEntry(new ZipEntry(imgName + suffix));
				InputStream fis = getInputStreamByGet(url);
				byte[] bytes = new byte[1024];
				int len;
				while (true) {
					assert fis != null;
					if ((len = fis.read(bytes)) == -1) break;
					zos.write(bytes, 0, len);
				}
				fis.close();
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			zos.flush();
			zos.close();
		}
	}

	public static InputStream getInputStreamByGet(String url) {
		try {
			HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
			conn.setReadTimeout(5000);
			conn.setConnectTimeout(5000);
			conn.setRequestMethod("GET");
			if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
				return conn.getInputStream();
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}
}

2. 测试方法

//1.启服务通过配置文件运行
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.photo.Photo;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * opencv测试
 * @author wangjiajin
 * @date 2021/3/2
 * @desc
 */
@RestController
@RequestMapping("/opencv")
@Api(tags = "opencv测试接口")
public class OpenCvTestController {

    @PostMapping("/clearWater")
    @ApiOperation(value = "图片去水印")
    public String clearWater() {
        String markContent = "测试生成水印";
        String waterPath = "D:\\img\\water.jpg";
        //通过原图加水印获得初始水印图
        ImageUtils.addWaterMark("D:\\img\\1.png", markContent, waterPath);
        //蒙版图路径
        String maskPath = "D:\\img\\mask.jpg";
        //获取蒙版图，黑底+透明水印字
        ImageUtils.getMask(waterPath, markContent, maskPath);
        //opencv读取水印图
        Mat image = Imgcodecs.imread(waterPath);
        //opencv读取蒙版
        Mat mask = Imgcodecs.imread(maskPath, CvType.CV_8UC1);
        Mat dst = new Mat(image.size(), CvType.CV_8UC3);
        Photo.inpaint(image, mask, dst, 20, Photo.INPAINT_TELEA);
        String originPath = "D:\\img\\test.jpg";
        Imgcodecs.imwrite(originPath, dst);
        return "成功";
    }
}

//2.通过main方法测试
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.highgui.HighGui;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.photo.Photo;

/**
 * opencv图片去水印测试
 * @author wangjiajin
 * @date 2021/3/2
 * @desc
 */
public class OpencvImageTest {

    public static void main(String[] args) throws Exception {
        //加载动态库，main方法无法通过配置文件加载
        System.load("D:\\opencv\\opencv\\build\\java\\x64\\opencv_java451.dll");
        String markContent = "测试生成水印";
        String waterPath = "D:\\img\\water.jpg";
        //通过原图加水印获得初始水印图
        ImageUtils.addWaterMark("D:\\img\\1.png", markContent, waterPath);
        //蒙版图路径
        String maskPath = "D:\\img\\mask.jpg";
        //获取蒙版图，黑底+透明水印字
        ImageUtils.getMask(waterPath, markContent, maskPath);
        //opencv读取水印图
        Mat image = Imgcodecs.imread(waterPath);
        if (image.empty()) {
            throw new Exception("image is empty");
        }
        //opencv读取蒙版
        Mat mask = Imgcodecs.imread(maskPath, CvType.CV_8UC1);
        Mat dst = new Mat(image.size(), CvType.CV_8UC3);
        Photo.inpaint(image, mask, dst, 20, Photo.INPAINT_TELEA);
        HighGui.imshow("原图", image);
        HighGui.imshow("蒙版", mask);
        HighGui.imshow("结果", dst);
        String originPath = "D:\\img\\test.jpg";
        Imgcodecs.imwrite(originPath, dst);
        HighGui.waitKey();
    }
}

3. 可能遇到的错误

org.opencv.imgcodecs.Imgcodecs.imread_1(Ljava/lang/String;)J
//解决方法，将pom中热部署依赖去掉即可
<!-- 热部署 -->
<!--<dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-devtools</artifactId>
     <scope>runtime</scope>
     <optional>true</optional>
 </dependency>-->

4. 测试结果