Merge branch 'bk_video'

# Conflicts:
#	app/src/main/java/com/example/ueberwachungssystem/MainActivity.java

app/build.gradle

     androidTestImplementation 'androidx.test.ext:junit:1.1.5'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
 
+
+    // OpenCV (from: https://github.com/QuickBirdEng/opencv-android)
+    def opencv_version = "4.5.3.0"
+    implementation "com.quickbirdstudios:opencv:${opencv_version}"
+
+    implementation "androidx.lifecycle:lifecycle-extensions:2.0.0"
+
+
     // Required for CameraX
     def camerax_version = "1.2.2"
     implementation "androidx.camera:camera-core:${camerax_version}"

app/src/main/AndroidManifest.xml

 
     <uses-feature android:name="android.hardware.camera"/>
     <uses-permission android:name="android.permission.CAMERA"/>
+    <uses-permission android:name="android.permission.RECORD_AUDIO" />
 
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+    <service android:name=".Detection.DetectorService"/>
     </application>
 
 </manifest>

app/src/main/java/com/example/ueberwachungssystem/Detection/AudioRecorder.java

+package com.example.ueberwachungssystem.Detection;
+
+import android.content.Context;
+import android.media.MediaPlayer;
+import android.media.MediaRecorder;
+import android.widget.Toast;
+
+import java.io.File;
+import java.io.IOException;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+
+public class AudioRecorder {
+    private final Context context;
+    private MediaRecorder mediaRecorder = null;
+    private boolean isRecording = false;
+    private File outputDir;      // Default: in app files directory
+
+
+    public AudioRecorder (Context context) {
+        this.context = context;
+        this.outputDir = context.getFilesDir();
+    }
+
+    public void startRecording() {
+        // Handle logic
+        if (outputDir == null)
+            return;
+        if (isRecording)
+            return;
+        isRecording = true;
+
+        // Setup Audio Recorder for output Format: 3GP
+        mediaRecorder = new MediaRecorder();
+        mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
+        mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
+        mediaRecorder.setOutputFile(outputDir + "/" + generateFileName() + ".3gp");
+        mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
+        try {
+            mediaRecorder.prepare();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        mediaRecorder.start();
+    }
+
+    public void stopRecording() {
+        if (mediaRecorder != null) {
+            mediaRecorder.stop();
+            mediaRecorder.reset();
+            mediaRecorder.release();
+            mediaRecorder = null;
+            isRecording = false;
+            Toast.makeText(context, "audio recording saved", Toast.LENGTH_SHORT).show();
+        }
+    }
+
+    public boolean isRecording(){
+        return isRecording;
+    }
+
+    public void setOutputDir(File outputDir) {
+        this.outputDir = outputDir;
+    }
+
+    private String generateFileName(){
+        // Get the current timestamp
+        LocalDateTime currentTime = LocalDateTime.now();
+        // Define the format for the timestamp
+        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd_HHmmss");
+        // Return the timestamp as a string
+        return currentTime.format(formatter);
+    }
+}

app/src/main/java/com/example/ueberwachungssystem/Detection/DetectionReport.java

     public String timeStamp;
     public String detectionType;
     public float detectedValue;
-    public String detectorID;
+    public boolean detectionState;
 
-    public DetectionReport(String detectorID, String detectionType, float detectedAmplitude) {
+    public DetectionReport(boolean detectionState, String detectionType, float detectedAmplitude) {
         this.timeStamp = String.valueOf(Calendar.getInstance().getTime());
         this.detectionType = detectionType;
         this.detectedValue = detectedAmplitude;
-        this.detectorID = detectorID;
+        this.detectionState = detectionState;
+
+        //this.detectorID = detectorID;
     }
 
 
     /** Get Detection Report in String format */
     public String toString() {
+        String state = "State: " + "[" + this.detectionState + "]";
         String time = "Time: " + "[" + this.timeStamp + "]";
         String type = "Type: " + "[" + this.detectionType + "]";
         String value = "Value: " + "[" + this.detectedValue + "]";
-        String id = "ID: " + "[" + this.detectorID + "]";
 
-        return String.join("\t", time, type, value, id);
+        return String.join("\t", state, time, type, value);
     }
 
     /** Debug Report */

app/src/main/java/com/example/ueberwachungssystem/Detection/Detector.java

 package com.example.ueberwachungssystem.Detection;
 
+import android.os.CountDownTimer;
+
 import androidx.annotation.NonNull;
+import androidx.camera.core.ExperimentalGetImage;
 
 
 abstract public class Detector {
     private OnDetectionListener listener;
+    private boolean isDetecting = false;
+    private boolean extendViolation = false;
+
+    // Countdown parameters
+    private final int COUNTDOWN_TIME = 10000;          // milliseconds
+    private final int COUNTDOWN_POLLING_TIME = 100;   // milliseconds
 
     /** Constructor - takes context of current activity */
     public Detector() {}
         this.listener = listener;
     }
 
-
     /** Triggers onDetectionListener - call this to trigger violation/alarm */
-    public void reportViolation(String detectorID, String detectionType, float amplitude) {
+    public void reportViolation(String detectionType, float amplitude) {
         if (listener != null) {
-            DetectionReport detectionReport = new DetectionReport(detectorID, detectionType, amplitude);
-            listener.onDetection(detectionReport);
+            if (!isDetecting) {
+                isDetecting = true;
+                DetectionReport detectionReport = new DetectionReport(true, detectionType, amplitude);
+                listener.onDetection(detectionReport);
+                startDetectionTimer(detectionType, amplitude);
+            } else {
+                extendViolation = true;
+            }
         } else {
-            throw new IllegalStateException("No listener set for violation reporting");
+            isDetecting = false;
+            extendViolation = false;
         }
     }
 
+    private void startDetectionTimer(String detectionType, float amplitude) {
+        isDetecting = true;
+        new CountDownTimer((long) COUNTDOWN_TIME, COUNTDOWN_POLLING_TIME) {
+            @Override
+            public void onTick(long millisUntilFinished) {
+                if (extendViolation) {
+                    extendViolation = false;
+                    startDetectionTimer(detectionType, amplitude);
+                    this.cancel();
+                }
+            }
+            @Override
+            public void onFinish() {
+                isDetecting = false;
+                DetectionReport detectionReport = new DetectionReport(false, detectionType, amplitude);
+                listener.onDetection(detectionReport);
+            }
+        }.start();
+    }
+
+    public void extendViolation(){
+        this.extendViolation = true;
+    }
 
     /** Starts Detection (abstract method: needs to be overridden in child class) */
     public abstract void startDetection();

app/src/main/java/com/example/ueberwachungssystem/Detection/DetectorService.java

+package com.example.ueberwachungssystem.Detection;
+
+import android.content.Intent;
+import android.os.Binder;
+import android.os.IBinder;
+import android.widget.ImageView;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.camera.core.ExperimentalGetImage;
+import androidx.lifecycle.LifecycleService;
+
+import java.io.File;
+
+@ExperimentalGetImage
+public class DetectorService extends LifecycleService {
+    public ServiceBinder serviceBinder = new ServiceBinder();
+    private DetectorService.OnDetectionListener listener;
+    private boolean isServiceRunning = false;
+
+    VideoDetector videoDetector = null;
+    AudioRecorder audioRecorder = null;
+
+
+    @Override
+    public int onStartCommand(Intent intent, int flags, int startId) {
+        if (isServiceRunning)
+            return START_NOT_STICKY;
+
+
+        // Setup Service classes:
+        videoDetector = new VideoDetector(this);
+        videoDetector.setOnDetectionListener(new Detector.OnDetectionListener() {
+            @Override
+            public void onDetection(@NonNull DetectionReport detectionReport) {
+                passToServiceListener(detectionReport);
+            }
+        });
+
+        audioRecorder = new AudioRecorder(this);
+
+
+
+        isServiceRunning = true;
+        return super.onStartCommand(intent, flags, startId);
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        isServiceRunning = false;
+    }
+
+    /** Service methods */
+    public class ServiceBinder extends Binder {
+        public DetectorService getBoundService() {
+            // Return an instance of the TestService
+            return DetectorService.this;
+        }
+    }
+    @Nullable
+    @Override
+    public IBinder onBind(Intent intent) {
+        super.onBind(intent);
+        return serviceBinder;
+    }
+
+
+    /** Video Detection */
+    public void startVideoDetection() {
+        if(videoDetector != null)
+            videoDetector.startDetection();
+    }
+    public void stopVideoDetection() {
+        if(videoDetector != null)
+            videoDetector.stopDetection();
+    }
+    public boolean isVideoDetectionRunning() {
+        if(videoDetector != null)
+           return videoDetector.isDetecting();
+        return false;
+    }
+    public void debugVideoProcessing(ImageView input, ImageView output) {
+        if(videoDetector != null)
+            videoDetector.debugProcessing(input, output);
+    }
+
+    /** Audio Detection */
+    public void startAudioDetection() {
+
+    }
+    public void stopAudioDetection() {
+
+    }
+
+    /** Motion Detection */
+    public void startMotionDetection() {
+
+    }
+    public void stopMotionDetection() {
+
+    }
+
+    /** Video Recording */
+    public void startVideoRecording() {
+        if(videoDetector != null)
+            videoDetector.startRecording();
+    }
+    public void stopVideoRecording() {
+        if(videoDetector != null)
+            videoDetector.stopRecording();
+    }
+    public boolean isVideoRecordingRunning() {
+        if(videoDetector != null)
+            return videoDetector.isRecording();
+        return false;
+    }
+    public void setVideoRecordingDir(File outputDir) {
+        if (videoDetector != null)
+            videoDetector.setOutputDir(outputDir);
+    }
+
+    /** Audio Recording */
+    public void startAudioRecording() {
+        if(audioRecorder != null)
+            audioRecorder.startRecording();
+    }
+    public void stopAudioRecording() {
+        if(audioRecorder != null)
+            audioRecorder.stopRecording();
+    }
+    public boolean isAudioRecordingRunning() {
+        if(videoDetector != null)
+            return audioRecorder.isRecording();
+        return false;
+    }
+    public void setAudioRecordingDir(File outputDir) {
+        if (audioRecorder != null)
+            audioRecorder.setOutputDir(outputDir);
+    }
+
+
+
+
+    /** pass Detection Report to Service Detection Listener and trigger it */
+    public void passToServiceListener(DetectionReport detectionReport) {
+        if (listener != null) {
+            listener.onDetection(detectionReport);
+        }
+    }
+
+
+    /** On Detection Listener - runs when violation is reported */
+    public interface OnDetectionListener {
+        void onDetection(@NonNull DetectionReport detectionReport);
+    }
+    public void setOnDetectionListener(@NonNull DetectorService.OnDetectionListener listener) {
+        this.listener = listener;
+    }
+}

app/src/main/java/com/example/ueberwachungssystem/Detection/OpenCVHelper.java

+package com.example.ueberwachungssystem.Detection;
+
+import android.graphics.Bitmap;
+import android.media.Image;
+import android.widget.ImageView;
+
+import androidx.annotation.NonNull;
+import androidx.camera.core.ExperimentalGetImage;
+import androidx.camera.core.ImageProxy;
+
+import org.opencv.android.Utils;
+import org.opencv.core.Core;
+import org.opencv.core.CvType;
+import org.opencv.core.Mat;
+import org.opencv.core.MatOfPoint;
+import org.opencv.core.Scalar;
+import org.opencv.core.Size;
+import org.opencv.imgproc.Imgproc;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+
+@ExperimentalGetImage
+public class OpenCVHelper {
+
+    /** OpenCV helper methods **/
+    public static Mat addGaussianBlur(Mat inputMat, Size kernelSize){
+        Mat outputMat = new Mat();
+        Imgproc.GaussianBlur(inputMat, outputMat, kernelSize, 0);
+        return outputMat;
+    }
+
+    public static Mat addBlur(Mat inputMat, Size kernelSize){
+        Mat outputMat = new Mat();
+        Imgproc.blur(inputMat, outputMat, kernelSize);
+        return outputMat;
+    }
+
+    public static Mat extractYChannel(@NonNull ImageProxy imgProxy) {
+        Image img = imgProxy.getImage();
+
+        assert img != null;
+        ByteBuffer yBuffer = img.getPlanes()[0].getBuffer();
+        byte[] yData = new byte[yBuffer.remaining()];
+        yBuffer.get(yData);
+
+        Mat yMat = new Mat(img.getHeight(), img.getWidth(), CvType.CV_8UC1);
+        yMat.put(0, 0, yData);
+
+        return yMat;
+    }
+
+    public static Mat thresholdPixels(Mat inputMat, Mat previousImage, int threshold){
+        Mat diffImage = new Mat();
+        Core.absdiff(inputMat, previousImage, diffImage);
+        Mat binaryMat = new Mat();
+        Imgproc.threshold(diffImage, binaryMat, threshold, 255, Imgproc.THRESH_BINARY);
+        return binaryMat;
+    }
+
+
+    public static Mat thresholdContourArea(Mat inputMat, float areaThreshold){
+        List<MatOfPoint> contours = new ArrayList<>();
+        Mat hierarchy = new Mat();
+        Imgproc.findContours(inputMat, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);
+
+        Mat outputMat = new Mat(inputMat.size(), inputMat.type(), new Scalar(0));
+        // Iterate over the contours and draw only the larger contours on the outputMat
+        for (MatOfPoint contour : contours) {
+            double contourArea = Imgproc.contourArea(contour);
+            if (contourArea > areaThreshold) {
+                Imgproc.drawContours(outputMat, Collections.singletonList(contour), 0, new Scalar(255), -1);
+            }
+        }
+        // Apply the outputMat as a mask to the dilatedImage
+        Mat maskedImage = new Mat();
+        inputMat.copyTo(maskedImage, outputMat);
+        return outputMat;
+    }
+
+    public static Mat dilateBinaryMat(Mat inputMat, Size kernelSize){
+        Mat dilatedMat = new Mat();
+        Mat kernel = Imgproc.getStructuringElement(Imgproc.MORPH_ELLIPSE, kernelSize);
+        Imgproc.dilate(inputMat, dilatedMat, kernel);
+        return dilatedMat;
+    }
+
+    public static int countNonZeroPixels(Mat inputImage) {
+        if (inputImage != null)
+            return Core.countNonZero(inputImage);
+        else
+            return 0;
+    }
+
+
+    public static void debugMat(Mat mat, ImageView imageView) {
+        if (imageView == null || mat == null)
+            return;
+
+        Bitmap bitmap = Bitmap.createBitmap(mat.cols(), mat.rows(), Bitmap.Config.ARGB_8888);
+        Utils.matToBitmap(mat, bitmap);
+
+        // Display the bitmap in an ImageView
+        imageView.setImageBitmap(bitmap);
+    }
+}

app/src/main/java/com/example/ueberwachungssystem/Detection/VideoDetector.java

 package com.example.ueberwachungssystem.Detection;
 
+import android.Manifest;
+import android.annotation.SuppressLint;
 import android.content.Context;
+import android.content.pm.PackageManager;
 import android.graphics.ImageFormat;
 import android.media.Image;
-import android.util.Size;
+import android.os.CountDownTimer;
+import android.util.Log;
+import android.view.Display;
+import android.view.Surface;
+import android.view.WindowManager;
+import android.widget.ImageView;
+import android.widget.Toast;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.camera.core.CameraSelector;
 import androidx.camera.core.ExperimentalGetImage;
 import androidx.camera.core.ImageAnalysis;
+import androidx.camera.core.ImageProxy;
 import androidx.camera.core.Preview;
+import androidx.camera.core.VideoCapture;
 import androidx.camera.lifecycle.ProcessCameraProvider;
 import androidx.camera.view.PreviewView;
+import androidx.core.app.ActivityCompat;
 import androidx.core.content.ContextCompat;
 import androidx.lifecycle.LifecycleOwner;
 
 import com.google.common.util.concurrent.ListenableFuture;
 
-import java.nio.ByteBuffer;
+import org.opencv.android.OpenCVLoader;
+import org.opencv.core.Mat;
+import org.opencv.core.Size;
+
+import java.io.File;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
 import java.util.concurrent.ExecutionException;
 
 
 /**
  * Video Detector inherits some methods from abstract Detector class (more info there)
- *
- *
  * USE FROM MAIN ACTIVITY:
- *
  * VideoDetector vd = new VideoDetector(this);
- * vd.setPreview(previewView);  //THIS IS OPTIONAL!
- * vd.setOnDetectionListener(new Detector.OnDetectionListener{...});
- * vd.startDetection();
- * vd.stopDetection
- *
  * */
 
 
 @ExperimentalGetImage
 public class VideoDetector extends Detector {
-
     // Calling Activity
     private final Context context;
+
     // Camera Provider
     private ProcessCameraProvider cameraProvider;
-    private Boolean isDetectionRunning = false;
-    // Preview Camera Image
-    private PreviewView previewView = null;
-    // Detect Violation
-    private static final float PIXEL_THRESHOLD = 30f;  // Luminosity (brightness channel of YUV_420_888)
-    private static final float ALARM_THRESHOLD = 0.2f;   // Percent of pixels changed
-    private ByteBuffer previousBuffer = null;
+    private ImageAnalysis imageAnalysis;
+    private VideoCapture videoCapture;
+    //private Preview preview;
 
+    // Logic
+    private boolean isDetecting = false;
+    private boolean isRecording = false;
+    private boolean allowReportViolation = false;
 
+    // Image Processing
+    private Mat previousImage = null;
 
-    /**
-     * Constructor
-     * @param context: the context of calling activity (usually "this")
-     * */
+    // Debugging
+    private ImageView inputImageView = null;
+    private ImageView outputImageView = null;
+
+    // Recorder
+    private File outputDir;      // Default: in app files directory
+
+
+    // Parameters
+    private static final float ALARM_THRESHOLD = 0f;   // Percent of pixels changed
+    private static final float AREA_THRESHOLD = 10f;
+    private static final int DILATE_ITERATIONS = 2;
+    private static final float START_DELAY = 20000;   // milliseconds
+    private static final android.util.Size IMAGE_RES = new android.util.Size(640, 480);
+
+
+
+    /** Constructor */
     public VideoDetector(Context context) {
         super();
         this.context = context;
+        this.imageAnalysis = setupImageAnalysis();
+        this.videoCapture = setupVideoCapture();
+        this.outputDir = context.getFilesDir();
+        //this.preview = new Preview.Builder().build();
     }
 
+    /** Get States */
+    public boolean isDetecting() {
+        return isDetecting;
+    }
+    public boolean isRecording(){
+        return isRecording;
+    }
 
-    /**
-     *  Starts the Video Detection
-     * */
+
+    /** Starts the Video Detection */
     @Override
     public void startDetection() {
-        if (isDetectionRunning)
+        // Check States
+        if (isDetecting)
             return;
-        // Request Camera Provider
+        // Configure Image Analysis
+        imageAnalysis = setupImageAnalysis();
+        // Open CV startup check
+        if (!OpenCVLoader.initDebug()) {
+            Log.e("OpenCV", "Unable to load OpenCV!");
+            return;
+        } else
+            Log.d("OpenCV", "OpenCV loaded Successfully!");
+        // Get Process Camera Provider and start
         final ListenableFuture<ProcessCameraProvider> cameraProviderFuture = ProcessCameraProvider.getInstance(context);
-        //Check for Camera availability
         cameraProviderFuture.addListener(() -> {
             try {
                 cameraProvider = cameraProviderFuture.get();
-                bindAnalysis(cameraProvider);
-                isDetectionRunning = true;
-                previousBuffer = null;
-            } catch (ExecutionException | InterruptedException e) {
-                // No errors need to be handled for this Future. This should never be reached.
-            }
-        },ContextCompat.getMainExecutor(context));
+                isDetecting = true;
+                bindCameraProvider();
+            } catch (ExecutionException | InterruptedException e) {}
+        }, ContextCompat.getMainExecutor(context));
+        // Disable Violation Calling for Setup Time
+        startViolationTimer(START_DELAY);
     }
 
+    /** Starts the Recorder */
+    @SuppressLint("RestrictedApi")
+    public void startRecording() {
+        // Check States
+        if (isRecording){
+            return;
+        }
 
-    /**
-     * Stops the Video Detection
-     * */
+        videoCapture = setupVideoCapture();
+
+        final ListenableFuture<ProcessCameraProvider> cameraProviderFuture = ProcessCameraProvider.getInstance(context);
+        cameraProviderFuture.addListener(() -> {
+            try {
+                cameraProvider = cameraProviderFuture.get();
+                isRecording = true;
+                bindCameraProvider();
+
+                File vidFile = new File(context.getFilesDir() + "/" + generateFileName() + ".mp4");
+                if (ActivityCompat.checkSelfPermission(context, Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
+                    return;
+                }
+                videoCapture.startRecording(
+                        new VideoCapture.OutputFileOptions.Builder(vidFile).build(),
+                        context.getMainExecutor(),
+                        new VideoCapture.OnVideoSavedCallback() {
+                            @Override
+                            public void onVideoSaved(@NonNull VideoCapture.OutputFileResults outputFileResults) {
+                                isRecording = false;
+                                Toast.makeText(context, "video recording saved", Toast.LENGTH_SHORT).show();
+                            }
+                            @Override
+                            public void onError(int videoCaptureError, @NonNull String message, @Nullable Throwable cause) {
+                                isRecording = false;
+                                Toast.makeText(context, "video recording failed", Toast.LENGTH_SHORT).show();
+                            }
+                        }
+                );
+            } catch (ExecutionException | InterruptedException ignored) {}
+        }, ContextCompat.getMainExecutor(context));
+    }
+
+    /** Stops the Video Detection */
     @Override
     public void stopDetection() {
-        if (!isDetectionRunning)
+        if (!isDetecting || imageAnalysis == null)
             return;
-        cameraProvider.unbindAll();
-        isDetectionRunning = false;
+        cameraProvider.unbind(imageAnalysis);
+        isDetecting = false;
+        allowReportViolation = false;
     }
 
+    /** Stops the Recording */
+    @SuppressLint("RestrictedApi")
+    public void stopRecording(){
+        if(!isRecording)
+            return;
 
-    /**
-     * Set PreviewView to show video feed while detecting
-     * this is optional and does not need to be called
-     * */
-    public void setPreviewView(PreviewView previewView) {
-        this.previewView = previewView;
+        videoCapture.stopRecording();
+        cameraProvider.unbind(videoCapture);
+        isRecording = false;
     }
 
+    /** Bind Camera Provider */
+    private void bindCameraProvider() {
+        // Specify which Camera to use
+        CameraSelector cameraSelector = new CameraSelector.Builder().requireLensFacing(CameraSelector.LENS_FACING_BACK).build();
+        cameraProvider.unbindAll();
+        cameraProvider.bindToLifecycle((LifecycleOwner) context, cameraSelector, imageAnalysis, videoCapture);
+    }
 
-    /**
-     * Binds the Luminosity Analyzer (configure and run Analysis)
-     * @param cameraProvider: CameraProvider of Context passed by Constructor
-     * */
-    private void bindAnalysis(@NonNull ProcessCameraProvider cameraProvider) {
+    /** Setup Use Cases */
+    private ImageAnalysis setupImageAnalysis() {
         // Configure and create Image Analysis
         ImageAnalysis.Builder builder = new ImageAnalysis.Builder();
-        builder.setTargetResolution(new Size(640, 480));
+        builder.setTargetResolution(IMAGE_RES);
         builder.setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST);
         builder.setOutputImageFormat(ImageAnalysis.OUTPUT_IMAGE_FORMAT_YUV_420_888);
+        builder.setTargetRotation(Surface.ROTATION_90);
         ImageAnalysis imageAnalysis = builder.build();
-
         // Set Analyzer
         imageAnalysis.setAnalyzer(ContextCompat.getMainExecutor(context), imageProxy -> {
             if (imageProxy.getFormat() == ImageFormat.YUV_420_888) {
                 Image image = imageProxy.getImage();
                 assert image != null;
 
-                // Changed Pixel Detection
-                int pixelChanged = getChangedPixelCount(image);
-                int width = image.getWidth();
-                int height = image.getHeight();
+                // Violation Handling
+                Mat processed = processImage(imageProxy);
 
-                float percentPixelChanged = (float) 100f * pixelChanged / (width * height);
+                int n = OpenCVHelper.countNonZeroPixels(processed);
+                int pixelCount = image.getWidth() * image.getHeight();
+                float percentChanged = (float) n / pixelCount;
 
-                if (percentPixelChanged > ALARM_THRESHOLD)
-                    reportViolation("0", "Video", percentPixelChanged);
+                // Violation Condition
+                if (percentChanged * 100 > ALARM_THRESHOLD) {
+                    if (allowReportViolation)
+                        reportViolation("Video", percentChanged);
+                }
             }
             imageProxy.close();
         });
-        // Create Preview
-        Preview preview = new Preview.Builder().build();
-        // Specify which Camera to use
-        CameraSelector cameraSelector = new CameraSelector.Builder().requireLensFacing(CameraSelector.LENS_FACING_BACK).build();
-        // Update PreviewView if set
-        if (previewView != null)
-            preview.setSurfaceProvider(previewView.getSurfaceProvider());
+        return imageAnalysis;
+    }
+
+    @SuppressLint("RestrictedApi")
+    private VideoCapture setupVideoCapture() {
+        int rotation = getDisplayRotation();
+        return new VideoCapture.Builder()
+                .setTargetRotation(rotation)
+                .build();
+    }
 
-        cameraProvider.bindToLifecycle((LifecycleOwner) context, cameraSelector, imageAnalysis, preview);
+    /** Process Image to be used for Motion Detection */
+    private Mat processImage(ImageProxy imageProxy){
+        if (imageProxy == null)
+            return null;
+        // Image Transformation
+        Mat imageMat = OpenCVHelper.extractYChannel(imageProxy);
+        // Show Input Image
+        if (inputImageView != null)
+            OpenCVHelper.debugMat(imageMat, inputImageView);
+        // Preprocess Image
+        Mat preprocessed = imageMat;
+        preprocessed = OpenCVHelper.addGaussianBlur(preprocessed, new Size(21, 21));
+        preprocessed = OpenCVHelper.addBlur(preprocessed, new Size(3, 3));
+        // Set Previous Image
+        if (previousImage == null) {
+            previousImage = preprocessed;
+            return null;
+        }
+        // Process Image
+        Mat processed = preprocessed.clone();
+        processed = OpenCVHelper.thresholdPixels(processed, previousImage, 25);
+
+        for(int i = 0; i < DILATE_ITERATIONS; i++)
+            processed = OpenCVHelper.dilateBinaryMat(processed, new Size(3,3));
+
+        processed = OpenCVHelper.thresholdContourArea(processed, AREA_THRESHOLD);
+        // Output
+        previousImage = preprocessed.clone();
+        // Show Output Image
+        if (outputImageView != null)
+            OpenCVHelper.debugMat(processed, outputImageView);
+        return processed;
     }
 
 
+    /** Debug input and result of processing */
+    public void debugProcessing(@NonNull ImageView inputImageView, @NonNull ImageView outputImageView){
+        this.inputImageView = inputImageView;
+        this.outputImageView = outputImageView;
+    }
 
     /**
-     * Calculate Amount of Pixels changed using a threshold
-     * @param image
-     * */
-    private int getChangedPixelCount(Image image) {
-        Image.Plane[] planes = image.getPlanes();
-        ByteBuffer buffer = planes[0].getBuffer();
-
-        if (previousBuffer == null) {
-            previousBuffer = ByteBuffer.allocate(buffer.capacity());
-            buffer.rewind();
-            previousBuffer.put(buffer);
-            previousBuffer.rewind();
-            return 0;
-        }
+    private void setPreviewView(@NonNull PreviewView previewView) {
+        // Create Preview
+        if (this.preview != null)
+            this.preview.setSurfaceProvider(previewView.getSurfaceProvider());
+    }
+     */
 
-        int width = image.getWidth();
-        int height = image.getHeight();
 
-        int yRowStride = image.getPlanes()[0].getRowStride();
-        int yPixelStride = image.getPlanes()[0].getPixelStride();
+    /** Generate File Name */
+    private String generateFileName(){
+        // Get the current timestamp
+        LocalDateTime currentTime = LocalDateTime.now();
+        // Define the format for the timestamp
+        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd_HHmmss");
+        // Return the timestamp as a string
+        return currentTime.format(formatter);
+    }
 
-        int changedPixelCount = 0;
 
-        // Count changed pixels
-        for (int y = 0; y < height; ++y) {
-            for (int x = 0; x < width; x++) {
-                int index = (y * yRowStride) + (x * yPixelStride);
-                int luminosity = (buffer.get(index) & 0xff);
-                int previousLuminosity = (previousBuffer.get(index) & 0xff);
-                int diff = Math.abs(luminosity - previousLuminosity);
-                if (diff > PIXEL_THRESHOLD)
-                    changedPixelCount++;
-            }
-        }
+    /** Get current Display Rotation */
+    private int getDisplayRotation() {
+        WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
+        Display display = windowManager.getDefaultDisplay();
+        return display.getRotation();
+    }
 
-        // Reset and copy Byte Buffer
-        buffer.rewind();
-        previousBuffer.rewind();
-        previousBuffer.put(buffer);
+    /** Start delay until Violation Report is allowed */
+    private void startViolationTimer(float setupTime) {
+        new CountDownTimer((long) (START_DELAY), 100) {
+            @Override
+            public void onTick(long millisUntilFinished) {
+            }
+            @Override
+            public void onFinish() {
+                allowReportViolation = true;
+            }
+        }.start();
+    }
 
-        return changedPixelCount;
+    public void setOutputDir(File outputDir) {
+        this.outputDir = outputDir;
     }
-}
+}

app/src/main/java/com/example/ueberwachungssystem/PermissionHandler.java

+package com.example.ueberwachungssystem;
+
+
+import android.app.Activity;
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.widget.Toast;
+
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+
+public class PermissionHandler {
+    private final Context context;
+    private static final int PERMISSION_REQUEST_CODE = 23409;
+    private static final String[] permissions = new String[]{
+            android.Manifest.permission.CAMERA,
+            android.Manifest.permission.RECORD_AUDIO
+    };
+
+    public PermissionHandler(Context context) {
+        this.context = context;
+    }
+
+    public boolean hasPermissions() {
+        boolean permissionState = true;
+        for (String permission: permissions) {
+            permissionState = permissionState && ContextCompat.checkSelfPermission(context, permission) == PackageManager.PERMISSION_GRANTED;
+        }
+        return permissionState;
+    }
+
+    public void getPermissions() {
+        if (!hasPermissions())
+            ActivityCompat.requestPermissions((Activity) context, permissions, PERMISSION_REQUEST_CODE);
+    }
+
+    public void showPermissionToast() {
+        if (hasPermissions())
+            Toast.makeText(context, "permissions available", Toast.LENGTH_SHORT).show();
+        else
+            Toast.makeText(context, "permissions missing", Toast.LENGTH_SHORT).show();
+    }
+}

app/src/main/res/layout/activity_main.xml

 <?xml version="1.0" encoding="utf-8"?>
-<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<LinearLayout 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"
+    android:layout_gravity="center"
+    android:gravity="top"
+    android:orientation="vertical"
     tools:context=".MainActivity">
 
-    <TextView
+
+    <androidx.camera.view.PreviewView
+        android:id="@+id/previewView"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:backgroundTint="@android:color/black"/>
+
+    <ToggleButton
+        android:id="@+id/toggleButton"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="ToggleButton" />
+
+    <ImageView
+        android:id="@+id/inputImageView"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:text="Hello World!"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
+        tools:srcCompat="@tools:sample/avatars" />
+
+    <ImageView
+        android:id="@+id/outputImageView"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        tools:srcCompat="@tools:sample/avatars" />
+
+    <androidx.camera.view.PreviewView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content" />
 
-</androidx.constraintlayout.widget.ConstraintLayout>
+</LinearLayout>