Android demo: finish implementing support for legacy camera so that luminance data is available for tracking.

Resolves #13013

Also make image access lazy to improve performance and clean up member variable declarations between CameraActivity.java and subclasses.

PiperOrigin-RevId: 169450498

6 files changed, 207 insertions, 211 deletions

diff --git a/tensorflow/examples/android/src/org/tensorflow/demo/CameraActivity.java b/tensorflow/examples/android/src/org/tensorflow/demo/CameraActivity.java
index 83cf9f0a2a..7e57c17467 100644
--- a/tensorflow/examples/android/src/org/tensorflow/demo/CameraActivity.java
+++ b/tensorflow/examples/android/src/org/tensorflow/demo/CameraActivity.java
@@ -21,7 +21,6 @@ import android.app.Activity;
 import android.app.Fragment;
 import android.content.Context;
 import android.content.pm.PackageManager;
-import android.graphics.Bitmap;
 import android.hardware.Camera;
 import android.hardware.camera2.CameraAccessException;
 import android.hardware.camera2.CameraCharacteristics;
@@ -41,15 +40,12 @@ import android.view.KeyEvent;
 import android.view.WindowManager;
 import android.widget.Toast;
 import java.nio.ByteBuffer;
-
 import org.tensorflow.demo.env.ImageUtils;
 import org.tensorflow.demo.env.Logger;
+import org.tensorflow.demo.R; // Explicit import needed for internal Google builds.
 
-// Explicit import needed for internal Google builds.
-import org.tensorflow.demo.R;
-
-public abstract class CameraActivity extends Activity implements OnImageAvailableListener, Camera.
-        PreviewCallback {
+public abstract class CameraActivity extends Activity
+    implements OnImageAvailableListener, Camera.PreviewCallback {
   private static final Logger LOGGER = new Logger();
 
   private static final int PERMISSIONS_REQUEST = 1;
@@ -62,19 +58,16 @@ public abstract class CameraActivity extends Activity implements OnImageAvailabl
   private Handler handler;
   private HandlerThread handlerThread;
   private boolean useCamera2API;
-  protected Bitmap rgbFrameBitmap = null;
+  private boolean isProcessingFrame = false;
+  private byte[][] yuvBytes = new byte[3][];
   private int[] rgbBytes = null;
+  private int yRowStride;
+
   protected int previewWidth = 0;
   protected int previewHeight = 0;
-  protected Bitmap croppedBitmap = null;
-  protected static final boolean SAVE_PREVIEW_BITMAP = false;
-  protected long lastProcessingTimeMs;
-  protected Bitmap cropCopyBitmap;
-  protected ResultsView resultsView;
-  protected boolean computing = false;
-  protected Runnable postInferenceCallback;
-  protected byte[][] yuvBytes=new byte[3][];
-  protected int yRowStride;
+
+  private Runnable postInferenceCallback;
+  private Runnable imageConverter;
 
   @Override
   protected void onCreate(final Bundle savedInstanceState) {
@@ -91,16 +84,31 @@ public abstract class CameraActivity extends Activity implements OnImageAvailabl
     }
   }
 
+  private byte[] lastPreviewFrame;
+
+  protected int[] getRgbBytes() {
+    imageConverter.run();
+    return rgbBytes;
+  }
+
+  protected int getLuminanceStride() {
+    return yRowStride;
+  }
+
+  protected byte[] getLuminance() {
+    return yuvBytes[0];
+  }
+
   /**
    * Callback for android.hardware.Camera API
    */
   @Override
   public void onPreviewFrame(final byte[] bytes, final Camera camera) {
-    if (computing) {
+    if (isProcessingFrame) {
+      LOGGER.w("Dropping frame!");
       return;
     }
-    computing = true;
-    yuvBytes[0] = bytes;
+
     try {
       // Initialize the storage bitmaps once when the resolution is known.
       if (rgbBytes == null) {
@@ -110,18 +118,33 @@ public abstract class CameraActivity extends Activity implements OnImageAvailabl
         rgbBytes = new int[previewWidth * previewHeight];
         onPreviewSizeChosen(new Size(previewSize.width, previewSize.height), 90);
       }
-      ImageUtils.convertYUV420SPToARGB8888(bytes, previewWidth, previewHeight, rgbBytes);
     } catch (final Exception e) {
       LOGGER.e(e, "Exception!");
       return;
     }
-    postInferenceCallback = new Runnable() {
-      @Override
-      public void run() {
-        camera.addCallbackBuffer(bytes);
-      }
-    };
-    processImageRGBbytes(rgbBytes);
+
+    isProcessingFrame = true;
+    lastPreviewFrame = bytes;
+    yuvBytes[0] = bytes;
+    yRowStride = previewWidth;
+
+    imageConverter =
+        new Runnable() {
+          @Override
+          public void run() {
+            ImageUtils.convertYUV420SPToARGB8888(bytes, previewWidth, previewHeight, rgbBytes);
+          }
+        };
+
+    postInferenceCallback =
+        new Runnable() {
+          @Override
+          public void run() {
+            camera.addCallbackBuffer(bytes);
+            isProcessingFrame = false;
+          }
+        };
+    processImage();
   }
 
   /**
@@ -129,51 +152,64 @@ public abstract class CameraActivity extends Activity implements OnImageAvailabl
    */
   @Override
   public void onImageAvailable(final ImageReader reader) {
-    Image image = null;
     //We need wait until we have some size from onPreviewSizeChosen
     if (previewWidth == 0 || previewHeight == 0) {
       return;
     }
-    rgbBytes = new int[previewWidth * previewHeight];
+    if (rgbBytes == null) {
+      rgbBytes = new int[previewWidth * previewHeight];
+    }
     try {
-      image = reader.acquireLatestImage();
+      final Image image = reader.acquireLatestImage();
 
       if (image == null) {
         return;
       }
 
-      if (computing) {
+      if (isProcessingFrame) {
         image.close();
         return;
       }
-      computing = true;
+      isProcessingFrame = true;
       Trace.beginSection("imageAvailable");
       final Plane[] planes = image.getPlanes();
       fillBytes(planes, yuvBytes);
       yRowStride = planes[0].getRowStride();
       final int uvRowStride = planes[1].getRowStride();
       final int uvPixelStride = planes[1].getPixelStride();
-      ImageUtils.convertYUV420ToARGB8888(
-          yuvBytes[0],
-          yuvBytes[1],
-          yuvBytes[2],
-          previewWidth,
-          previewHeight,
-          yRowStride,
-          uvRowStride,
-          uvPixelStride,
-          rgbBytes);
-      image.close();
 
+      imageConverter =
+          new Runnable() {
+            @Override
+            public void run() {
+              ImageUtils.convertYUV420ToARGB8888(
+                  yuvBytes[0],
+                  yuvBytes[1],
+                  yuvBytes[2],
+                  previewWidth,
+                  previewHeight,
+                  yRowStride,
+                  uvRowStride,
+                  uvPixelStride,
+                  rgbBytes);
+            }
+          };
+
+      postInferenceCallback =
+          new Runnable() {
+            @Override
+            public void run() {
+              image.close();
+              isProcessingFrame = false;
+            }
+          };
+
+      processImage();
     } catch (final Exception e) {
-      if (image != null) {
-        image.close();
-      }
       LOGGER.e(e, "Exception!");
       Trace.endSection();
       return;
     }
-    processImageRGBbytes(rgbBytes);
     Trace.endSection();
   }
 
@@ -235,15 +271,13 @@ public abstract class CameraActivity extends Activity implements OnImageAvailabl
   @Override
   public void onRequestPermissionsResult(
       final int requestCode, final String[] permissions, final int[] grantResults) {
-    switch (requestCode) {
-      case PERMISSIONS_REQUEST: {
-        if (grantResults.length > 0
-            && grantResults[0] == PackageManager.PERMISSION_GRANTED
-            && grantResults[1] == PackageManager.PERMISSION_GRANTED) {
-          setFragment();
-        } else {
-          requestPermission();
-        }
+    if (requestCode == PERMISSIONS_REQUEST) {
+      if (grantResults.length > 0
+          && grantResults[0] == PackageManager.PERMISSION_GRANTED
+          && grantResults[1] == PackageManager.PERMISSION_GRANTED) {
+        setFragment();
+      } else {
+        requestPermission();
       }
     }
   }
@@ -269,7 +303,8 @@ public abstract class CameraActivity extends Activity implements OnImageAvailabl
   }
 
   // Returns true if the device supports the required hardware level, or better.
-  boolean isHardwareLevelSupported(CameraCharacteristics characteristics, int requiredLevel) {
+  private boolean isHardwareLevelSupported(
+      CameraCharacteristics characteristics, int requiredLevel) {
     int deviceLevel = characteristics.get(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL);
     if (deviceLevel == CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY) {
       return requiredLevel == deviceLevel;
@@ -331,7 +366,8 @@ public abstract class CameraActivity extends Activity implements OnImageAvailabl
       camera2Fragment.setCamera(cameraId);
       fragment = camera2Fragment;
     } else {
-      fragment = new LegacyCameraConnectionFragment(this, getLayoutId());
+      fragment =
+          new LegacyCameraConnectionFragment(this, getLayoutId(), getDesiredPreviewFrameSize());
     }
 
     getFragmentManager()
@@ -384,7 +420,14 @@ public abstract class CameraActivity extends Activity implements OnImageAvailabl
     return super.onKeyDown(keyCode, event);
   }
 
-  protected abstract void processImageRGBbytes(int[] rgbBytes ) ;
+  protected void readyForNextImage() {
+    if (postInferenceCallback != null) {
+      postInferenceCallback.run();
+    }
+  }
+
+  protected abstract void processImage();
+
   protected abstract void onPreviewSizeChosen(final Size size, final int rotation);
   protected abstract int getLayoutId();
   protected abstract Size getDesiredPreviewFrameSize();
diff --git a/tensorflow/examples/android/src/org/tensorflow/demo/CameraConnectionFragment.java b/tensorflow/examples/android/src/org/tensorflow/demo/CameraConnectionFragment.java
index 986f2777b2..361cf0e87c 100644
--- a/tensorflow/examples/android/src/org/tensorflow/demo/CameraConnectionFragment.java
+++ b/tensorflow/examples/android/src/org/tensorflow/demo/CameraConnectionFragment.java
@@ -59,7 +59,7 @@ import java.util.List;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
 import org.tensorflow.demo.env.Logger;
-import org.tensorflow.demo.R;
+import org.tensorflow.demo.R; // Explicit import needed for internal Google builds.
 
 public class CameraConnectionFragment extends Fragment {
   private static final Logger LOGGER = new Logger();
@@ -265,7 +265,7 @@ public class CameraConnectionFragment extends Fragment {
    * @param height The minimum desired height
    * @return The optimal {@code Size}, or an arbitrary one if none were big enough
    */
-  private static Size chooseOptimalSize(final Size[] choices, final int width, final int height) {
+  protected static Size chooseOptimalSize(final Size[] choices, final int width, final int height) {
     final int minSize = Math.max(Math.min(width, height), MINIMUM_PREVIEW_SIZE);
     final Size desiredSize = new Size(width, height);
 
diff --git a/tensorflow/examples/android/src/org/tensorflow/demo/ClassifierActivity.java b/tensorflow/examples/android/src/org/tensorflow/demo/ClassifierActivity.java
index ab48e2265b..b29fa1546c 100644
--- a/tensorflow/examples/android/src/org/tensorflow/demo/ClassifierActivity.java
+++ b/tensorflow/examples/android/src/org/tensorflow/demo/ClassifierActivity.java
@@ -22,26 +22,32 @@ import android.graphics.Canvas;
 import android.graphics.Matrix;
 import android.graphics.Paint;
 import android.graphics.Typeface;
-
 import android.media.ImageReader.OnImageAvailableListener;
 import android.os.SystemClock;
 import android.util.Size;
 import android.util.TypedValue;
 import android.view.Display;
-
 import java.util.List;
 import java.util.Vector;
 import org.tensorflow.demo.OverlayView.DrawCallback;
 import org.tensorflow.demo.env.BorderedText;
 import org.tensorflow.demo.env.ImageUtils;
 import org.tensorflow.demo.env.Logger;
-
-// Explicit import needed for internal Google builds.
-import org.tensorflow.demo.R;
+import org.tensorflow.demo.R; // Explicit import needed for internal Google builds.
 
 public class ClassifierActivity extends CameraActivity implements OnImageAvailableListener {
   private static final Logger LOGGER = new Logger();
 
+  protected static final boolean SAVE_PREVIEW_BITMAP = false;
+
+  private ResultsView resultsView;
+
+  private Bitmap rgbFrameBitmap = null;
+  private Bitmap croppedBitmap = null;
+  private Bitmap cropCopyBitmap = null;
+
+  private long lastProcessingTimeMs;
+
   // These are the settings for the original v1 Inception model. If you want to
   // use a model that's been produced from the TensorFlow for Poets codelab,
   // you'll need to set IMAGE_SIZE = 299, IMAGE_MEAN = 128, IMAGE_STD = 128,
@@ -136,8 +142,6 @@ public class ClassifierActivity extends CameraActivity implements OnImageAvailab
     cropToFrameTransform = new Matrix();
     frameToCropTransform.invert(cropToFrameTransform);
 
-    yuvBytes = new byte[3][];
-
     addCallback(
         new DrawCallback() {
           @Override
@@ -147,8 +151,9 @@ public class ClassifierActivity extends CameraActivity implements OnImageAvailab
         });
   }
 
-  protected void processImageRGBbytes(int[] rgbBytes ) {
-    rgbFrameBitmap.setPixels(rgbBytes, 0, previewWidth, 0, 0, previewWidth, previewHeight);
+  @Override
+  protected void processImage() {
+    rgbFrameBitmap.setPixels(getRgbBytes(), 0, previewWidth, 0, 0, previewWidth, previewHeight);
     final Canvas canvas = new Canvas(croppedBitmap);
     canvas.drawBitmap(rgbFrameBitmap, frameToCropTransform, null);
 
@@ -165,15 +170,12 @@ public class ClassifierActivity extends CameraActivity implements OnImageAvailab
             lastProcessingTimeMs = SystemClock.uptimeMillis() - startTime;
             LOGGER.i("Detect: %s", results);
             cropCopyBitmap = Bitmap.createBitmap(croppedBitmap);
-            if (resultsView==null) {
+            if (resultsView == null) {
               resultsView = (ResultsView) findViewById(R.id.results);
             }
             resultsView.setResults(results);
             requestRender();
-            computing = false;
-            if (postInferenceCallback != null) {
-              postInferenceCallback.run();
-            }
+            readyForNextImage();
           }
         });
   }
diff --git a/tensorflow/examples/android/src/org/tensorflow/demo/DetectorActivity.java b/tensorflow/examples/android/src/org/tensorflow/demo/DetectorActivity.java
index 91b2831306..3c80a2ae3c 100644
--- a/tensorflow/examples/android/src/org/tensorflow/demo/DetectorActivity.java
+++ b/tensorflow/examples/android/src/org/tensorflow/demo/DetectorActivity.java
@@ -25,12 +25,8 @@ import android.graphics.Paint;
 import android.graphics.Paint.Style;
 import android.graphics.RectF;
 import android.graphics.Typeface;
-import android.media.Image;
-import android.media.Image.Plane;
-import android.media.ImageReader;
 import android.media.ImageReader.OnImageAvailableListener;
 import android.os.SystemClock;
-import android.os.Trace;
 import android.util.Size;
 import android.util.TypedValue;
 import android.view.Display;
@@ -44,7 +40,7 @@ import org.tensorflow.demo.env.BorderedText;
 import org.tensorflow.demo.env.ImageUtils;
 import org.tensorflow.demo.env.Logger;
 import org.tensorflow.demo.tracking.MultiBoxTracker;
-import org.tensorflow.demo.R;
+import org.tensorflow.demo.R; // Explicit import needed for internal Google builds.
 
 /**
  * An activity that uses a TensorFlowMultiBoxDetector and ObjectTracker to detect and then track
@@ -104,30 +100,23 @@ public class DetectorActivity extends CameraActivity implements OnImageAvailable
 
   private Classifier detector;
 
-  private int previewWidth = 0;
-  private int previewHeight = 0;
-  private byte[][] yuvBytes;
-  private int[] rgbBytes = null;
+  private long lastProcessingTimeMs;
   private Bitmap rgbFrameBitmap = null;
   private Bitmap croppedBitmap = null;
+  private Bitmap cropCopyBitmap = null;
 
-  private boolean computing = false;
+  private boolean computingDetection = false;
 
   private long timestamp = 0;
 
   private Matrix frameToCropTransform;
   private Matrix cropToFrameTransform;
 
-  private Bitmap cropCopyBitmap;
-
   private MultiBoxTracker tracker;
 
-  private byte[] luminance;
+  private byte[] luminanceCopy;
 
   private BorderedText borderedText;
-
-  private long lastProcessingTimeMs;
-
   @Override
   public void onPreviewSizeChosen(final Size size, final int rotation) {
     final float textSizePx =
@@ -187,7 +176,6 @@ public class DetectorActivity extends CameraActivity implements OnImageAvailable
     sensorOrientation = rotation + screenOrientation;
 
     LOGGER.i("Initializing at size %dx%d", previewWidth, previewHeight);
-    rgbBytes = new int[previewWidth * previewHeight];
     rgbFrameBitmap = Bitmap.createBitmap(previewWidth, previewHeight, Config.ARGB_8888);
     croppedBitmap = Bitmap.createBitmap(cropSize, cropSize, Config.ARGB_8888);
 
@@ -199,7 +187,6 @@ public class DetectorActivity extends CameraActivity implements OnImageAvailable
 
     cropToFrameTransform = new Matrix();
     frameToCropTransform.invert(cropToFrameTransform);
-    yuvBytes = new byte[3][];
 
     trackingOverlay = (OverlayView) findViewById(R.id.tracking_overlay);
     trackingOverlay.addCallback(
@@ -260,82 +247,47 @@ public class DetectorActivity extends CameraActivity implements OnImageAvailable
   OverlayView trackingOverlay;
 
   @Override
-  public void onImageAvailable(final ImageReader reader) {
-    Image image = null;
-
+  protected void processImage() {
     ++timestamp;
     final long currTimestamp = timestamp;
+    byte[] originalLuminance = getLuminance();
+    tracker.onFrame(
+        previewWidth,
+        previewHeight,
+        getLuminanceStride(),
+        sensorOrientation,
+        originalLuminance,
+        timestamp);
+    trackingOverlay.postInvalidate();
+
+    // No mutex needed as this method is not reentrant.
+    if (computingDetection) {
+      readyForNextImage();
+      return;
+    }
+    computingDetection = true;
+    LOGGER.i("Preparing image " + currTimestamp + " for detection in bg thread.");
 
-    try {
-      image = reader.acquireLatestImage();
-
-      if (image == null) {
-        return;
-      }
-
-      Trace.beginSection("imageAvailable");
-
-      final Plane[] planes = image.getPlanes();
-      fillBytes(planes, yuvBytes);
-
-      tracker.onFrame(
-          previewWidth,
-          previewHeight,
-          planes[0].getRowStride(),
-          sensorOrientation,
-          yuvBytes[0],
-          timestamp);
-      trackingOverlay.postInvalidate();
+    rgbFrameBitmap.setPixels(getRgbBytes(), 0, previewWidth, 0, 0, previewWidth, previewHeight);
 
-      // No mutex needed as this method is not reentrant.
-      if (computing) {
-        image.close();
-        return;
-      }
-      computing = true;
-
-      final int yRowStride = planes[0].getRowStride();
-      final int uvRowStride = planes[1].getRowStride();
-      final int uvPixelStride = planes[1].getPixelStride();
-      ImageUtils.convertYUV420ToARGB8888(
-          yuvBytes[0],
-          yuvBytes[1],
-          yuvBytes[2],
-          previewWidth,
-          previewHeight,
-          yRowStride,
-          uvRowStride,
-          uvPixelStride,
-          rgbBytes);
-
-      image.close();
-    } catch (final Exception e) {
-      if (image != null) {
-        image.close();
-      }
-      LOGGER.e(e, "Exception!");
-      Trace.endSection();
-      return;
+    if (luminanceCopy == null) {
+      luminanceCopy = new byte[originalLuminance.length];
     }
+    System.arraycopy(originalLuminance, 0, luminanceCopy, 0, originalLuminance.length);
+    readyForNextImage();
 
-    rgbFrameBitmap.setPixels(rgbBytes, 0, previewWidth, 0, 0, previewWidth, previewHeight);
     final Canvas canvas = new Canvas(croppedBitmap);
     canvas.drawBitmap(rgbFrameBitmap, frameToCropTransform, null);
-
     // For examining the actual TF input.
     if (SAVE_PREVIEW_BITMAP) {
       ImageUtils.saveBitmap(croppedBitmap);
     }
 
-    if (luminance == null) {
-      luminance = new byte[yuvBytes[0].length];
-    }
-    System.arraycopy(yuvBytes[0], 0, luminance, 0, luminance.length);
-
     runInBackground(
         new Runnable() {
           @Override
           public void run() {
+            LOGGER.i("Running detection on image " + currTimestamp);
             final long startTime = SystemClock.uptimeMillis();
             final List<Classifier.Recognition> results = detector.recognizeImage(croppedBitmap);
             lastProcessingTimeMs = SystemClock.uptimeMillis() - startTime;
@@ -349,9 +301,15 @@ public class DetectorActivity extends CameraActivity implements OnImageAvailable
 
             float minimumConfidence = MINIMUM_CONFIDENCE_TF_OD_API;
             switch (MODE) {
-                case TF_OD_API: minimumConfidence = MINIMUM_CONFIDENCE_TF_OD_API; break;
-                case MULTIBOX: minimumConfidence = MINIMUM_CONFIDENCE_MULTIBOX; break;
-                case YOLO: minimumConfidence = MINIMUM_CONFIDENCE_YOLO; break;
+              case TF_OD_API:
+                minimumConfidence = MINIMUM_CONFIDENCE_TF_OD_API;
+                break;
+              case MULTIBOX:
+                minimumConfidence = MINIMUM_CONFIDENCE_MULTIBOX;
+                break;
+              case YOLO:
+                minimumConfidence = MINIMUM_CONFIDENCE_YOLO;
+                break;
             }
 
             final List<Classifier.Recognition> mappedRecognitions =
@@ -368,19 +326,15 @@ public class DetectorActivity extends CameraActivity implements OnImageAvailable
               }
             }
 
-            tracker.trackResults(mappedRecognitions, luminance, currTimestamp);
+            tracker.trackResults(mappedRecognitions, luminanceCopy, currTimestamp);
             trackingOverlay.postInvalidate();
 
             requestRender();
-            computing = false;
+            computingDetection = false;
           }
         });
-
-    Trace.endSection();
   }
 
-  protected void processImageRGBbytes(int[] rgbBytes ) {}
-
   @Override
   protected int getLayoutId() {
     return R.layout.camera_connection_fragment_tracking;
diff --git a/tensorflow/examples/android/src/org/tensorflow/demo/LegacyCameraConnectionFragment.java b/tensorflow/examples/android/src/org/tensorflow/demo/LegacyCameraConnectionFragment.java
index e5b3eeeceb..a317273acd 100644
--- a/tensorflow/examples/android/src/org/tensorflow/demo/LegacyCameraConnectionFragment.java
+++ b/tensorflow/examples/android/src/org/tensorflow/demo/LegacyCameraConnectionFragment.java
@@ -1,7 +1,7 @@
 package org.tensorflow.demo;
 
 /*
- * Copyright 2014 The Android Open Source Project
+ * Copyright 2017 The TensorFlow Authors. All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,31 +18,29 @@ package org.tensorflow.demo;
 
 import android.app.Fragment;
 import android.graphics.SurfaceTexture;
+import android.hardware.Camera;
+import android.hardware.Camera.CameraInfo;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.HandlerThread;
+import android.util.Size;
 import android.util.SparseIntArray;
 import android.view.LayoutInflater;
 import android.view.Surface;
 import android.view.TextureView;
 import android.view.View;
 import android.view.ViewGroup;
-
 import java.io.IOException;
-
-import android.hardware.Camera;
-import android.hardware.Camera.CameraInfo;
-
+import java.util.List;
+import org.tensorflow.demo.env.ImageUtils;
 import org.tensorflow.demo.env.Logger;
-
-// Explicit import needed for internal Google builds.
-import org.tensorflow.demo.R;
+import org.tensorflow.demo.R; // Explicit import needed for internal Google builds.
 
 public class LegacyCameraConnectionFragment extends Fragment {
-
   private Camera camera;
   private static final Logger LOGGER = new Logger();
   private Camera.PreviewCallback imageListener;
+  private Size desiredSize;
 
   /**
    * The layout identifier to inflate for this Fragment.
@@ -50,10 +48,10 @@ public class LegacyCameraConnectionFragment extends Fragment {
   private int layout;
 
   public LegacyCameraConnectionFragment(
-      final Camera.PreviewCallback imageListener,
-      final int layout) {
+      final Camera.PreviewCallback imageListener, final int layout, final Size desiredSize) {
     this.imageListener = imageListener;
     this.layout = layout;
+    this.desiredSize = desiredSize;
   }
 
   /**
@@ -85,6 +83,16 @@ public class LegacyCameraConnectionFragment extends Fragment {
             Camera.Parameters parameters = camera.getParameters();
             parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
 
+            List<Camera.Size> cameraSizes = parameters.getSupportedPreviewSizes();
+            Size[] sizes = new Size[cameraSizes.size()];
+            int i = 0;
+            for (Camera.Size size : cameraSizes) {
+              sizes[i++] = new Size(size.width, size.height);
+            }
+            Size previewSize =
+                CameraConnectionFragment.chooseOptimalSize(
+                    sizes, desiredSize.getWidth(), desiredSize.getHeight());
+            parameters.setPreviewSize(previewSize.getWidth(), previewSize.getHeight());
             camera.setDisplayOrientation(90);
             camera.setParameters(parameters);
             camera.setPreviewTexture(texture);
@@ -94,8 +102,7 @@ public class LegacyCameraConnectionFragment extends Fragment {
 
           camera.setPreviewCallbackWithBuffer(imageListener);
           Camera.Size s = camera.getParameters().getPreviewSize();
-          int bufferSize = s.height * s.width * 3 / 2;
-          camera.addCallbackBuffer(new byte[bufferSize]);
+          camera.addCallbackBuffer(new byte[ImageUtils.getYUVByteSize(s.height, s.width)]);
 
           textureView.setAspectRatio(s.height, s.width);
 
@@ -104,8 +111,7 @@ public class LegacyCameraConnectionFragment extends Fragment {
 
         @Override
         public void onSurfaceTextureSizeChanged(
-            final SurfaceTexture texture, final int width, final int height) {
-        }
+            final SurfaceTexture texture, final int width, final int height) {}
 
         @Override
         public boolean onSurfaceTextureDestroyed(final SurfaceTexture texture) {
@@ -113,8 +119,7 @@ public class LegacyCameraConnectionFragment extends Fragment {
         }
 
         @Override
-        public void onSurfaceTextureUpdated(final SurfaceTexture texture) {
-        }
+        public void onSurfaceTextureUpdated(final SurfaceTexture texture) {}
       };
 
   /**
diff --git a/tensorflow/examples/android/src/org/tensorflow/demo/StylizeActivity.java b/tensorflow/examples/android/src/org/tensorflow/demo/StylizeActivity.java
index 58dd5c6069..6a66ec3927 100644
--- a/tensorflow/examples/android/src/org/tensorflow/demo/StylizeActivity.java
+++ b/tensorflow/examples/android/src/org/tensorflow/demo/StylizeActivity.java
@@ -28,14 +28,9 @@ import android.graphics.Paint;
 import android.graphics.Paint.Style;
 import android.graphics.Rect;
 import android.graphics.Typeface;
-import android.hardware.Camera;
-import android.media.Image;
-import android.media.Image.Plane;
-import android.media.ImageReader;
 import android.media.ImageReader.OnImageAvailableListener;
 import android.os.Bundle;
 import android.os.SystemClock;
-import android.os.Trace;
 import android.util.Size;
 import android.util.TypedValue;
 import android.view.Display;
@@ -59,9 +54,7 @@ import org.tensorflow.demo.OverlayView.DrawCallback;
 import org.tensorflow.demo.env.BorderedText;
 import org.tensorflow.demo.env.ImageUtils;
 import org.tensorflow.demo.env.Logger;
-
-// Explicit import needed for internal Google builds.
-import org.tensorflow.demo.R;
+import org.tensorflow.demo.R; // Explicit import needed for internal Google builds.
 
 /**
  * Sample activity that stylizes the camera preview according to "A Learned Representation For
@@ -98,8 +91,10 @@ public class StylizeActivity extends CameraActivity implements OnImageAvailableL
 
   private Integer sensorOrientation;
 
-  private int previewWidth = 0;
-  private int previewHeight = 0;
+  private long lastProcessingTimeMs;
+  private Bitmap rgbFrameBitmap = null;
+  private Bitmap croppedBitmap = null;
+  private Bitmap cropCopyBitmap = null;
 
   private final float[] styleVals = new float[NUM_STYLES];
   private int[] intValues;
@@ -457,18 +452,18 @@ public class StylizeActivity extends CameraActivity implements OnImageAvailableL
 
     cropToFrameTransform = new Matrix();
     frameToCropTransform.invert(cropToFrameTransform);
-    yuvBytes = new byte[3][];
     intValues = new int[desiredSize * desiredSize];
     floatValues = new float[desiredSize * desiredSize * 3];
     initializedSize = desiredSize;
   }
 
-  protected void processImageRGBbytes(int[] rgbBytes ) {
+  @Override
+  protected void processImage() {
     if (desiredSize != initializedSize) {
       LOGGER.i(
           "Initializing at size preview size %dx%d, stylize size %d",
           previewWidth, previewHeight, desiredSize);
-      
+
       rgbFrameBitmap = Bitmap.createBitmap(previewWidth, previewHeight, Config.ARGB_8888);
       croppedBitmap = Bitmap.createBitmap(desiredSize, desiredSize, Config.ARGB_8888);
       frameToCropTransform = ImageUtils.getTransformationMatrix(
@@ -478,12 +473,11 @@ public class StylizeActivity extends CameraActivity implements OnImageAvailableL
 
       cropToFrameTransform = new Matrix();
       frameToCropTransform.invert(cropToFrameTransform);
-      yuvBytes = new byte[3][];
       intValues = new int[desiredSize * desiredSize];
       floatValues = new float[desiredSize * desiredSize * 3];
       initializedSize = desiredSize;
     }
-    rgbFrameBitmap.setPixels(rgbBytes, 0, previewWidth, 0, 0, previewWidth, previewHeight);
+    rgbFrameBitmap.setPixels(getRgbBytes(), 0, previewWidth, 0, 0, previewWidth, previewHeight);
     final Canvas canvas = new Canvas(croppedBitmap);
     canvas.drawBitmap(rgbFrameBitmap, frameToCropTransform, null);
 
@@ -492,21 +486,19 @@ public class StylizeActivity extends CameraActivity implements OnImageAvailableL
       ImageUtils.saveBitmap(croppedBitmap);
     }
 
-    runInBackground(new Runnable() {
-      @Override
-      public void run() {
-        cropCopyBitmap = Bitmap.createBitmap(croppedBitmap);
-        final long startTime = SystemClock.uptimeMillis();
-        stylizeImage(croppedBitmap);
-        lastProcessingTimeMs = SystemClock.uptimeMillis() - startTime;
-        textureCopyBitmap = Bitmap.createBitmap(croppedBitmap);
-        requestRender();
-        computing = false;
-        if (postInferenceCallback != null) {
-          postInferenceCallback.run();
-        }
-      }
-    });
+    runInBackground(
+        new Runnable() {
+          @Override
+          public void run() {
+            cropCopyBitmap = Bitmap.createBitmap(croppedBitmap);
+            final long startTime = SystemClock.uptimeMillis();
+            stylizeImage(croppedBitmap);
+            lastProcessingTimeMs = SystemClock.uptimeMillis() - startTime;
+            textureCopyBitmap = Bitmap.createBitmap(croppedBitmap);
+            requestRender();
+            readyForNextImage();
+          }
+        });
     if (desiredSize != initializedSize) {
       resetPreviewBuffers();
     }
@@ -540,7 +532,7 @@ public class StylizeActivity extends CameraActivity implements OnImageAvailableL
     }
 
     // Copy the input data into TensorFlow.
-    LOGGER.i("Width: %s , Height: %s",bitmap.getWidth(),bitmap.getHeight());
+    LOGGER.i("Width: %s , Height: %s", bitmap.getWidth(), bitmap.getHeight());
     inferenceInterface.feed(
         INPUT_NODE, floatValues, 1, bitmap.getWidth(), bitmap.getHeight(), 3);
     inferenceInterface.feed(STYLE_NODE, styleVals, NUM_STYLES);