Release image buffer as soon as possible in lib

facerecognitionlibrary/src/main/java/ch/zhaw/facerecognitionlibrary/Helpers/FaceDetection.java

@@ -146,6 +146,8 @@ public Eyes getEyes(Mat img){
         Mat leftHalfImg = img.submat(leftHalf);
         leftEyeDetector.detectMultiScale(leftHalfImg, leftEyes);
 
+        rightHalfImg.release();
+        leftHalfImg.release();
         if (rightEyes.empty() || leftEyes.empty() || rightEyes.toArray().length > 1 || leftEyes.toArray().length > 1){
             return null;
         }

facerecognitionlibrary/src/main/java/ch/zhaw/facerecognitionlibrary/PreProcessor/PreProcessor.java

@@ -19,6 +19,7 @@
 import android.graphics.Bitmap;
 import android.graphics.PointF;
 import android.media.FaceDetector;
+import android.util.Log;
 
 import org.opencv.android.Utils;
 import org.opencv.core.Core;
@@ -84,9 +85,11 @@ public void setFaces(PreProcessorFactory.PreprocessingMode preprocessingMode) {
 
         if (preprocessingMode == PreProcessorFactory.PreprocessingMode.RECOGNITION && preferencesHelper.getDetectionMethod()){
             // Change the image rotation to the angle where the face was detected
-            images.remove(0);
+            Mat img = images.remove(0);
             images.add(faceDetection.getImg());
-            setImages(images);
+            if(img != faceDetection.getImg()) {
+                img.release();
+            }
         }
     }
 
@@ -141,4 +144,26 @@ public void setImg(Mat img) {
     public void normalize0255(Mat norm){
         Core.normalize(norm, norm, 0, 255, Core.NORM_MINMAX, CvType.CV_8UC1);
     }
+
+    //Release images
+    public void releaseImages() {
+        if (images == null || images.size() == 0)
+            return;
+        try {
+            for (int i = 0; i < images.size(); i++) {
+                if (images.get(i) != null) {
+                    images.get(i).release();
+                } else {
+                    Log.e("PreProcessor","releaseImages null image(" + i + "/" + images.size() +")");
+                    break;
+                }
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            images.clear();
+            images = null;
+        }
+    }
+
 }

facerecognitionlibrary/src/main/java/ch/zhaw/facerecognitionlibrary/PreProcessor/PreProcessorFactory.java

@@ -46,7 +46,6 @@ public class PreProcessorFactory {
     public enum PreprocessingMode {DETECTION, RECOGNITION};
     private PreProcessor preProcessorRecognition;
     private PreProcessor preProcessorDetection;
-    private List<Mat> images;
     public CommandFactory commandFactory;
     private FaceDetection faceDetection;
     private boolean eyeDetectionEnabled;
@@ -72,24 +71,32 @@ public PreProcessorFactory(Context context) {
     public List<Mat> getCroppedImage(Mat img){
         preProcessorDetection = new PreProcessor(faceDetection, getCopiedImageList(img), context);
         List<String> preprocessingsDetection = getPreprocessings(PreferencesHelper.Usage.DETECTION);
-        images = new ArrayList<Mat>();
+        ArrayList<Mat> images = new ArrayList<Mat>();
         images.add(img);
         preProcessorRecognition = new PreProcessor(faceDetection, images, context);
 
         try {
             preprocess(preProcessorDetection, preprocessingsDetection);
             preProcessorRecognition.setFaces(PreprocessingMode.RECOGNITION);
+            if(preProcessorRecognition.getFaces() == null || preProcessorRecognition.getFaces().length == 0) {
+                Log.d("getCroppedImage", "No face detected");
+                return null;
+            }
+
             preProcessorRecognition = commandFactory.executeCommand(resources.getString(R.string.crop), preProcessorRecognition);
             if (eyeDetectionEnabled) {
                 Eyes[] eyes = preProcessorRecognition.setEyes();
                 if (eyes == null || eyes[0] == null){
+                    preProcessorRecognition.releaseImages();
                     return null;
                 }
             }
             preProcessorRecognition.setImages(Resize.preprocessImage(preProcessorRecognition.getImages(), preferencesHelper.getFaceSize()));
         } catch (NullPointerException e){
             Log.d("getCroppedImage", "No face detected");
             return null;
+        } finally {
+            preProcessorDetection.releaseImages();
         }
         return preProcessorRecognition.getImages();
     }
@@ -98,21 +105,28 @@ public List<Mat> getProcessedImage(Mat img, PreprocessingMode preprocessingMode)
 
         preProcessorDetection = new PreProcessor(faceDetection, getCopiedImageList(img), context);
 
-        images = new ArrayList<Mat>();
+        ArrayList<Mat> images = new ArrayList<Mat>();
         images.add(img);
         preProcessorRecognition = new PreProcessor(faceDetection, images, context);
 
         try {
             preprocess(preProcessorDetection, getPreprocessings(PreferencesHelper.Usage.DETECTION));
 
             preProcessorDetection.setFaces(preprocessingMode);
+
+            if(preProcessorDetection.getFaces()==null || preProcessorDetection.getFaces().length == 0) {
+                preProcessorDetection.releaseImages();
+                return null;
+            }
             preProcessorRecognition.setFaces(preProcessorDetection.getFaces());
             preProcessorRecognition.setAngle(preProcessorDetection.getAngle());
             preProcessorRecognition = commandFactory.executeCommand(resources.getString(R.string.crop), preProcessorRecognition);
 
             if (eyeDetectionEnabled) {
                 Eyes[] eyes = preProcessorRecognition.setEyes();
                 if (eyes == null || eyes[0] == null){
+                    preProcessorDetection.releaseImages();
+                    preProcessorRecognition.releaseImages();
                     return null;
                 }
             }
@@ -122,12 +136,14 @@ public List<Mat> getProcessedImage(Mat img, PreprocessingMode preprocessingMode)
             }
 
         } catch (NullPointerException e){
+            preProcessorDetection.releaseImages();
             Log.d("getProcessedImage", "No face detected");
             return null;
         }
         if (preprocessingMode == PreprocessingMode.DETECTION){
             return preProcessorDetection.getImages();
         } else {
+            preProcessorDetection.releaseImages();
             return preProcessorRecognition.getImages();
         }
     }

facerecognitionlibrary/src/main/java/ch/zhaw/facerecognitionlibrary/Recognition/Caffe.java

@@ -82,7 +82,10 @@ public boolean train() {
 
     @Override
     public String recognize(Mat img, String expectedLabel) {
-        return rec.recognize(getFeatureVector(img), expectedLabel);
+        Mat feature = getFeatureVector(img);
+        String str = rec.recognize(feature, expectedLabel);
+        feature.release();
+        return str;
     }
 
     @Override

facerecognitionlibrary/src/main/java/ch/zhaw/facerecognitionlibrary/Recognition/KNearestNeighbor.java

@@ -83,7 +83,7 @@ public String recognize(Mat img, String expectedLabel) {
         img = getFeatureVector(img);
         addImage(img, expectedLabel, true);
         nearest = knn.findNearest(img,k,result);
-
+        img.release();
         return labelMap.getKey((int) nearest);
     }
 

facerecognitionlibrary/src/main/java/ch/zhaw/facerecognitionlibrary/Recognition/TensorFlow.java

@@ -103,7 +103,10 @@ public boolean train() {
 
     @Override
     public String recognize(Mat img, String expectedLabel) {
-        return rec.recognize(getFeatureVector(img), expectedLabel);
+        Mat feature = getFeatureVector(img);
+        String str = rec.recognize(feature, expectedLabel);
+        feature.release();
+        return str;
     }
 
     @Override