OpenCV应用程序-Android相机在10秒钟后崩溃

Question

背景

在这个应用程序中，我能够启动我的相机预览，这是在Android Studio中开发的，目的是将OpenCV纳入其中。然而，我面临一个错误；相机预览仅持续约10秒，直到崩溃并关闭应用程序。有什么办法解决这个问题吗？这是我的密码；

MainActivity.java

package com.example.cv;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import android.Manifest;
import android.content.pm.PackageManager;
import android.opengl.Matrix;
import android.os.Bundle;
import android.util.Log;
import android.view.SurfaceView;
import android.widget.Toast;
import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.JavaCameraView;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgproc.Imgproc;
public class MainActivity extends AppCompatActivity implements CameraBridgeViewBase.CvCameraViewListener2
{
private static String TAG = "MainActivity";
JavaCameraView javaCameraView;
Mat mRGBA, mRGBAT;
private static final int MY_CAMERA_REQUEST_CODE = 100;

BaseLoaderCallback baseLoaderCallback = new BaseLoaderCallback(MainActivity.this) {
@Override
public void onManagerConnected(int status)
{
if (status == BaseLoaderCallback.SUCCESS) {
javaCameraView.enableView();
} else {
super.onManagerConnected(status);
}
}
};
static
{
if (OpenCVLoader.initDebug())
{
Log.d(TAG, "OpenCV is Configured or Connected successfully.");
}
else
{
Log.d(TAG, "OpenCV not Working or Loaded.");
}
}
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
javaCameraView = (JavaCameraView) findViewById(R.id.my_camera_view);

if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
== PackageManager.PERMISSION_GRANTED)  {
Log.d(TAG, "Permissions granted");
javaCameraView.setCameraPermissionGranted();
javaCameraView.setCameraIndex(CameraBridgeViewBase.CAMERA_ID_BACK);
javaCameraView.setVisibility(CameraBridgeViewBase.VISIBLE);
javaCameraView.setCvCameraViewListener(this);
} else {
Log.d(TAG, "Permission prompt");
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA}, MY_CAMERA_REQUEST_CODE);
}
}
@Override
public void onCameraViewStarted(int width, int height)
{
mRGBA = new Mat(height, width, CvType.CV_8UC4);
}
@Override
public void onCameraViewStopped()
{
mRGBA.release();
}
@Override
public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame)
{
mRGBA = inputFrame.rgba();
mRGBAT = mRGBA.t();
Core.flip(mRGBA.t(), mRGBAT, 1);
Imgproc.resize(mRGBAT, mRGBAT, mRGBA.size());
return mRGBAT;
}
@Override
public void onPointerCaptureChanged(boolean hasCapture) {
}

@Override
protected void onDestroy() {
super.onDestroy();
if (javaCameraView != null)
{
javaCameraView.disableView();
}
}
@Override
protected void onPause() {
super.onPause();
if (javaCameraView != null)
{
javaCameraView.disableView();
}
}

@Override
protected void onResume() {
super.onResume();
if (OpenCVLoader.initDebug())
{
Log.d(TAG, "OpenCV is Configured or Connected successfully.");
baseLoaderCallback.onManagerConnected(BaseLoaderCallback.SUCCESS);
}
else
{
Log.d(TAG, "OpenCV not Working or Loaded.");
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION, this, baseLoaderCallback);
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == MY_CAMERA_REQUEST_CODE) {
// camera can be turned on
Toast.makeText(this, "camera permission granted", Toast.LENGTH_LONG).show();
javaCameraView.setCameraPermissionGranted();
javaCameraView.setCameraIndex(CameraBridgeViewBase.CAMERA_ID_FRONT);
javaCameraView.setVisibility(CameraBridgeViewBase.VISIBLE);
javaCameraView.setCvCameraViewListener(this);
} else {
//camera will stay off
Toast.makeText(this, "camera permission denied", Toast.LENGTH_LONG).show();
}
}
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.cv">

<uses-permission android:name="android.permission.CAMERA"/>
<uses-feature android:name="android.hardware.camera"/>
<uses-feature android:name="android.hardware.camera.autofocus"/>
<uses-feature android:name="android.hardware.camera.front"/>
<uses-feature android:name="android.hardware.camera.front.autofocus"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">

<org.opencv.android.JavaCameraView
android:id="@+id/my_camera_view"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
</RelativeLayout>

Answer 1

我对您的问题进行了进一步的调查，以下是一些注意事项：

1-我已经在之前回答的评论中建议您，一旦不再需要onCameraFrame()中的矩阵，就立即发布它们。忘记这一点可能会产生垃圾收集问题，如本答案或此处所述。您可以使用Mat.release()方法显式调用此过程，就像用户在相同的答案中所做的那样。你试过了吗？根据我的测试，它延长了相机的10秒寿命，尽管还没有修复
2-从这个答案中，我们可以理解，转换太多次可能会造成其他麻烦。让我们来看看你的代码：

mRGBAT = mRGBA.t();
Core.flip(mRGBA.t(), mRGBAT, 1);

这看起来确实是我们可以改进的地方。您首先将mRGBA.t()分配给mRGBAT，但在调用Core.flip()时再次要求计算mRGBA的转置矩阵。结果已经存储在mRGBAT中，因此不需要再次执行这样的操作。然后你可以这样解决这个问题：

mRGBAT = mRGBA.t();
Core.flip(mRGBAT, mRGBAT, 1);

3-Mat.t()和Core.transpose()之间没有真正的区别，但第一个是第二个的包装，我们可以直接使用后一个

将解决您问题的整个片段如下：

Mat mRGBA, mRGBAT, dst;
@Override
public void onCameraViewStarted(int width, int height)
{
mRGBAT = new Mat();
dst = new Mat();
}
@Override
public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame)
{
mRGBA = inputFrame.rgba();
Core.transpose(mRGBA, mRGBAT);
Core.flip(mRGBAT, mRGBAT, 1);
Imgproc.resize(mRGBAT, dst, mRGBA.size());
mRGBA.release();
mRGBAT.release();
return dst;
}