JAVA中通過JavaCV實現跨平台視頻/圖像處理-調用攝像頭

一、簡介

　　JavaCV使用來自計算機視覺領域(OpenCV, FFmpeg, libdc1394, PGR FlyCapture, OpenKinect, librealsense, CL PS3 Eye Driver, videoInput, ARToolKitPlus, flandmark, Leptonica, and Tesseract)領域的研究人員常用庫的JavaCPP預設的封裝。提供實用程序類，使其功能更易於在Java平台上使用，包括Android。

 

二、案例1：調用攝像頭

（1）使用IDEA新建Maven項目，然后在pom.xml中引入下列依賴（因為要用到opencv來實現，所以需要引入opencv-platform包，此包會自動引入各大平台的依賴jar（內含dll））：

        <!-- https://mvnrepository.com/artifact/org.bytedeco/javacv-platform -->
        <dependency>
            <groupId>org.bytedeco</groupId>
            <artifactId>javacv-platform</artifactId>
            <version>1.4.1</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.bytedeco.javacpp-presets/opencv-platform -->
        <dependency>
            <groupId>org.bytedeco.javacpp-presets</groupId>
            <artifactId>opencv-platform</artifactId>
            <version>3.4.1-1.4.1</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

（2）測試類

import org.bytedeco.javacv.*;
import org.junit.Test;

import javax.swing.*;
import java.util.EnumSet;

public class JavaCVTest {

    @Test
    public void testCamera() throws InterruptedException, FrameGrabber.Exception {
        OpenCVFrameGrabber grabber = new OpenCVFrameGrabber(0);
        grabber.start();   //開始獲取攝像頭數據
        CanvasFrame canvas = new CanvasFrame("攝像頭");//新建一個窗口
        canvas.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        canvas.setAlwaysOnTop(true);
        while (true) {
            if (!canvas.isDisplayable()) {//窗口是否關閉
                grabber.stop();//停止抓取
                System.exit(-1);//退出
            }

            Frame frame = grabber.grab();

            canvas.showImage(frame);//獲取攝像頭圖像並放到窗口上顯示， 這里的Frame frame=grabber.grab(); frame是一幀視頻圖像
            Thread.sleep(50);//50毫秒刷新一次圖像
        }
    }

    @Test
    public void testCamera1() throws FrameGrabber.Exception, InterruptedException {
        VideoInputFrameGrabber grabber = VideoInputFrameGrabber.createDefault(0);
        grabber.start();
        CanvasFrame canvasFrame = new CanvasFrame("攝像頭");
        canvasFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        canvasFrame.setAlwaysOnTop(true);
        while (true) {
            if (!canvasFrame.isDisplayable()) {
                grabber.stop();
                System.exit(-1);
            }
            Frame frame = grabber.grab();
            canvasFrame.showImage(frame);
            Thread.sleep(30);
        }
    }
}

（3）兩種方法的測試效果：