來自樹莓派相機的OpenCV捕獲

Question

如何從標準相機模塊v2中插入Raspberry Pi 3B來捕獲在OpenCV中使用的圖像？我一直試圖讓高幀率視頻工作，但使用OpenCV的VideoCapture總是給我一個空的Mat當我嘗試索引設備0和this和this都產生1幀每秒或更糟糕時，我嘗試。我也研究過生成raspivid進程，但我沒有看到讓OpenCV的VideoCapture從該進程的輸出中讀取的方法。

如何在Java中獲得高FPS幀捕獲？有沒有辦法讓OpenCV從我從另一個進程中獲取的OutputStream中讀取數據？

編輯：我的代碼的簡化版本如下。我想知道如何填充startRecording()功能在這一類

abstract class Main { 
    public static Mat currentCapture = null; 
    public static final double FOV_HEIGHT = 48.8; 
    public static final int WIDTH = 480; 
    public static final int HEIGHT = 384; 
    public static final int VIDEO_WIDTH = WIDTH * 2; 
    public static final int VIDEO_HEIGHT = HEIGHT * 2; 

    static { 
     System.loadLibrary(org.opencv.core.Core.NATIVE_LIBRARY_NAME); 
    } 

    public static void main(String[] args) { 
     client = new VisionClientTable("10.55.6.4", 5506); 
     new Thread(new VisionThread(VisionThread.Mode.VIDEO)).start(); 
     new Thread(new VisionThread(VisionThread.Mode.TARGETING)).start(); 
    } 

    private static class VisionThread implements Runnable { 
     private final Mode mode; 

     enum Mode { 
      VIDEO, 
      TARGETING 
     } 

     public VisionThread(Mode mode) { 
      this.mode = mode; 
     } 

     @Override 
     public void run() { 
      if (mode == Mode.TARGETING) 
       startTracking(); 
      else if (mode == Mode.VIDEO) 
       startRecording(); 
     } 
    } 

    public static void startTracking() { 
     /* this thread repeatedly captures currentCapture and processes it */ 
    } 

    // this is where I need help 
    public static void startRecording() { 
     try { 
      VideoWriter video = new VideoWriter("/home/pi/vision/videos/video-" + Files.list(Paths.get("/home/pi/vision/captures")).count() + ".mp4", VideoWriter.fourcc('X', '2', '6', '4'), 30, new Size(VIDEO_WIDTH, VIDEO_HEIGHT), true); 
      VideoCapture capture = new VideoCapture(0); 
      capture.set(Videoio.CAP_PROP_FRAME_WIDTH, VIDEO_WIDTH); 
      capture.set(Videoio.CAP_PROP_FRAME_HEIGHT, VIDEO_HEIGHT); 
      Thread.sleep(2000); 
      while (true) { 
       long start = System.currentTimeMillis(); 
       Mat mat = new Mat(); 
       capture.read(mat); 
       if (!mat.empty()) { // mat is always empty 
        Mat downscaled = new Mat(); 
        Imgproc.resize(mat, downscaled, new Size(WIDTH, HEIGHT), 0, 0, Imgproc.INTER_NEAREST); 
        currentCapture = downscaled; 
       } 
       video.write(mat); 
       long end = System.currentTimeMillis(); 
       if (end - start < 1000/60) 
        Thread.sleep(1000/60 - (end - start)); 
      } 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
    } 

    public static void log(String text) { 
     System.out.println(text); 
    } 
} 

我覺得這樣做可能是設置raspivid輸出到文件的最好方法，不知何故它的輸出送入OpenCV的，但我不知道如何做到這一點。

編輯2：到目前爲止，我一直在使用Runtime.getRuntime().exec()運行raspivid命令輸出到文件，其中工程嘗試過，但後來當我嘗試打開與OpenCV的那個文件，capture.isOpened()仍然假的，即使在程序反覆嘗試打開文件。

Answer 1

對你的問題的代碼沒有太多的瞭解。 以下可能會對您有所幫助。

http://bigdinotech.com/tutorials/beaglebone-black-tutorials/building-opencv-on-the-beaglebone-black-or-raspberry-pi/