我该如何从插在覆盆子pi3b上的标准相机模块v2中捕获一幅图像,以便在opencv中使用?我一直在尝试让高帧速率的视频工作,但使用opencv的 VideoCapture
总是给我一个空的 Mat
当我尝试索引设备时 0
,这个和这个都产生了每秒1帧或者更糟。我也研究过如何产生 raspivid
过程,但我看不到一个方法来获得opencv的 VideoCapture
从这个过程的输出中读取。
如何在java中获得高fps帧捕获?有没有办法让opencv从 OutputStream
我从另一个过程中得到的?
编辑:下面是我的代码的简化版本。我想知道如何填充 startRecording()
该类中的函数
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);
}
}
我觉得最好的办法就是 raspivid
输出到一个文件,并以某种方式将其输出馈送到opencv中,但我不知道如何做到这一点。
编辑2:到目前为止,我已经尝试使用 Runtime.getRuntime().exec()
运行 raspivid
命令输出到一个文件,这是可行的,但是当我试图用opencv打开这个文件时, capture.isOpened()
仍然为false,即使程序反复尝试打开该文件。
1条答案
按热度按时间3vpjnl9f1#
从你的问题中不太了解你的代码。以下内容可能会对您有所帮助。
http://bigdinotech.com/tutorials/beaglebone-black-tutorials/building-opencv-on-the-beaglebone-black-or-raspberry-pi/