Refactored Detector

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

@@ -1,6 +1,9 @@
 package com.example.ueberwachungssystem.Detection;
 
+import android.Manifest;
+import android.app.Activity;
 import android.content.Context;
+import android.content.pm.PackageManager;
 import android.graphics.Bitmap;
 import android.graphics.ImageFormat;
 import android.media.Image;
@@ -14,6 +17,7 @@ import androidx.camera.core.ExperimentalGetImage;
 import androidx.camera.core.ImageAnalysis;
 import androidx.camera.core.Preview;
 import androidx.camera.lifecycle.ProcessCameraProvider;
+import androidx.core.app.ActivityCompat;
 import androidx.core.content.ContextCompat;
 import androidx.lifecycle.LifecycleOwner;
 
@@ -47,17 +51,20 @@ public class VideoDetector extends Detector {
 
     // Calling Activity
     private final Context context;
+    // Permission handling
+    private static final int CAMERA_PERMISSION_REQUEST_CODE = 3691;
     // Camera Provider
     private ProcessCameraProvider cameraProvider;
-    private Boolean isDetectionRunning = false;
-    // Detection
-    private Mat previousImage = null;
+    private boolean isDetectionRunning = false;
 
+    // Debugging
+    private Mat previousImage = null;
     public ImageView imageView1 = null;
     public ImageView imageView2 = null;
 
 
 
+
     // Parameters
     private static final float PIXEL_THRESHOLD = 40f;  // Luminosity (brightness channel of YUV_420_888)
     private static final int BLUR_KERNEL_SIZE = 5;
@@ -79,6 +86,15 @@ public class VideoDetector extends Detector {
         this.context = context;
     }
 
+
+    /**
+     * Get State of the Detector
+     */
+    public boolean isRunning() {
+        return isDetectionRunning;
+    }
+
+
     /**
      *  Starts the Video Detection
      * */
@@ -87,6 +103,10 @@ public class VideoDetector extends Detector {
         if (isDetectionRunning)
             return;
 
+        if (!isCameraAccessAllowed()){
+            getCameraAccess();
+        }
+
         // Open CV startup check
         if (!OpenCVLoader.initDebug()) {
             Log.e("OpenCV", "Unable to load OpenCV!");
@@ -121,6 +141,19 @@ public class VideoDetector extends Detector {
     }
 
 
+    /**
+     * Permission handling
+     */
+    private boolean isCameraAccessAllowed() {
+        return ContextCompat.checkSelfPermission(context, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED;
+    }
+
+    private void getCameraAccess() {
+        if (!isCameraAccessAllowed())
+            ActivityCompat.requestPermissions((Activity) context, new String[]{android.Manifest.permission.CAMERA}, CAMERA_PERMISSION_REQUEST_CODE);
+    }
+
+
     /**
      * Binds the Luminosity Analyzer (configure and run Analysis)
      * @param cameraProvider: CameraProvider of Context passed by Constructor
@@ -177,6 +210,12 @@ public class VideoDetector extends Detector {
         }.start();
     }
 
+
+    /**
+     * Process Image to be used for Motion Detection
+     *
+     * @param image: OpenCV Mat file that should be processed
+     */
     private Mat processImage(Mat image){
         if (previousImage == null) {
             previousImage = image;
@@ -184,7 +223,7 @@ public class VideoDetector extends Detector {
         }
 
         Mat mat = addGaussianBlur(image, BLUR_KERNEL_SIZE);
-        mat = thresholdPixels(mat, previousImage, PIXEL_THRESHOLD);
+        mat = thresholdPixels(mat, previousImage);
         mat = dilateNonZero(mat, DILATE_KERNEL_SIZE);
         mat = thresholdContourArea(mat, CONTOUR_THRESHOLD);
 
@@ -192,6 +231,12 @@ public class VideoDetector extends Detector {
         return mat;
     }
 
+    /**
+     * Convert Android Image to OpenCV Mat file with only y-Channel
+     *
+     * @param img: Android Image
+     * @return yChannel of Image in OpenCV Mat Format
+     */
     private Mat extractYChannel(@NonNull Image img) {
         ByteBuffer yBuffer = img.getPlanes()[0].getBuffer();
         byte[] yData = new byte[yBuffer.remaining()];
@@ -203,17 +248,28 @@ public class VideoDetector extends Detector {
         return yMat;
     }
 
-
-    private Mat thresholdPixels(Mat inputMat, Mat previousImage, float luminosityThreshold){
+    /**
+     * Threshold all Pixels
+     * @param inputMat: Input Image
+     * @param previousImage: previous Image (openCV Mat)
+     * @return Binary Mat Image
+     */
+    private Mat thresholdPixels(Mat inputMat, Mat previousImage){
         Mat diffImage = new Mat();
         Core.absdiff(inputMat, previousImage, diffImage);
 
         Mat binaryMat = new Mat();
-        Imgproc.threshold(diffImage, binaryMat, luminosityThreshold, 255, Imgproc.THRESH_BINARY);
+        Imgproc.threshold(diffImage, binaryMat, VideoDetector.PIXEL_THRESHOLD, 255, Imgproc.THRESH_BINARY);
 
         return binaryMat;
     }
 
+    /**
+     * Dilate Pixels of Binary Image
+     * @param inputMat: Input Image
+     * @param kernelSize: kernel Size
+     * @return binary Image with dilated Pixels
+     */
     private Mat dilateNonZero(Mat inputMat, int kernelSize){
         Mat dilatedMat = new Mat();
         Mat kernel = Imgproc.getStructuringElement(Imgproc.MORPH_ELLIPSE, new org.opencv.core.Size(kernelSize, kernelSize));
@@ -221,12 +277,25 @@ public class VideoDetector extends Detector {
         return dilatedMat;
     }
 
+    /**
+     * Add Gaussian Blur to OpenCV Mat Image
+     * @param inputMat: Input Image
+     * @param kernelSize: kernel Size
+     * @return Mat Image
+     */
     private Mat addGaussianBlur(Mat inputMat, int kernelSize){
         Mat outputMat = new Mat();
         Imgproc.GaussianBlur(inputMat, outputMat, new org.opencv.core.Size(kernelSize, kernelSize), 0);
         return outputMat;
     }
 
+
+    /**
+     * Filter Contour Areas by Size
+     * @param inputMat: Input Image
+     * @param areaThreshold: Threshold
+     * @return Binary Mat Image
+     */
     private Mat thresholdContourArea(Mat inputMat, float areaThreshold){
         List<MatOfPoint> contours = new ArrayList<>();
         Mat hierarchy = new Mat();
@@ -246,6 +315,11 @@ public class VideoDetector extends Detector {
         return outputMat;
     }
 
+    /**
+     * Count all Pixels that are non Zero
+     * @param inputImage: Input Image in OpenCV Mat Format
+     * @return Count of Pixels that are non zero
+     */
     private int countNonZeroPixels(Mat inputImage) {
         if (inputImage != null)
             return Core.countNonZero(inputImage);
@@ -253,6 +327,11 @@ public class VideoDetector extends Detector {
             return 0;
     }
 
+    /**
+     * Show OpenCV Mat on ImageView
+     * @param mat: current OpenCV Mat Image
+     * @param imageView: ImageView xml-Element
+     */
     private void debugMat(Mat mat, ImageView imageView) {
         if (imageView == null || mat == null)
             return;

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

@@ -31,7 +31,6 @@ public class MainActivity extends AppCompatActivity {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
 
-        getCameraAccess();
 
         ImageView imageView = findViewById(R.id.imageView);
         ImageView ogiv = findViewById(R.id.ogiv);
@@ -48,27 +47,4 @@ public class MainActivity extends AppCompatActivity {
         });
         vd.startDetection();
     }
-
-    private boolean isCameraAccessAllowed() {
-        return ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED;
-    }
-
-    private void getCameraAccess() {
-        if (!isCameraAccessAllowed())
-            ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.CAMERA}, CAMERA_PERMISSION_REQUEST_CODE);
-    }
-
-    @Override
-    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
-        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
-
-        if (requestCode == CAMERA_PERMISSION_REQUEST_CODE && grantResults.length > 0) {
-            boolean cameraRights = grantResults[0] == PackageManager.PERMISSION_GRANTED;
-            if (cameraRights) {
-                Toast.makeText(this, "camera permission granted", Toast.LENGTH_LONG).show();
-            } else {
-                Toast.makeText(this, "camera permission denied", Toast.LENGTH_LONG).show();
-            }
-        }
-    }
 }