Fix the `FacePreview` example to use the C++ API of OpenCV

bytedeco · Jan 30, 2019 · 736f3428f7c09ed89d15917d7c98dd849716311f · 736f342
1 parent 21816c3
commit 736f3428f7c09ed89d15917d7c98dd849716311f
Unified Split

Showing with 24 additions and 31 deletions.

+24 −31 samples/FacePreview.java
diff --git a/samples/FacePreview.java b/samples/FacePreview.java
@@ -1,10 +1,10 @@
 /*
-  
- * Copyright (C) 2010,2011,2012 Samuel Audet
+  
+ * Copyright (C) 2010-2019 Samuel Audet
 *
 * FacePreview - A fusion of OpenCV's facedetect and Android's CameraPreview samples,
 *               with JavaCV + JavaCPP as the glue in between.
 *
-  
- * This file was based on CameraPreview.java that came with the Samples for 
+  
+ * This file was based on CameraPreview.java that came with the Samples for
 * Android SDK API 8, revision 1 and contained the following copyright notice:
 *
 * Copyright (C) 2007 The Android Open Source Project
@@ -66,15 +66,13 @@
 import android.widget.FrameLayout;
 import java.io.File;
 import java.io.IOException;
+  
+import java.net.URL;
 import java.nio.ByteBuffer;
 import java.util.List;
 import org.bytedeco.javacpp.Loader;
-  
-import org.bytedeco.javacpp.opencv_objdetect;
 import static org.bytedeco.javacpp.opencv_core.*;
-  
-import static org.bytedeco.javacpp.opencv_imgproc.*;
 import static org.bytedeco.javacpp.opencv_objdetect.*;
-  
-import static org.bytedeco.javacpp.opencv_imgcodecs.*;
 // ----------------------------------------------------------------------
@@ -112,30 +110,26 @@ protected void onCreate(Bundle savedInstanceState) {
 class FaceView extends View implements Camera.PreviewCallback {
    public static final int SUBSAMPLING_FACTOR = 4;
-  
-    private IplImage grayImage;
-  
-    private CvHaarClassifierCascade classifier;
-  
-    private CvMemStorage storage;
-  
-    private CvSeq faces;
+  
+    private Mat grayImage;
+  
+    private CascadeClassifier classifier;
+  
+    private RectVector faces;
    public FaceView(FacePreview context) throws IOException {
        super(context);
        // Load the classifier file from Java resources.
        File classifierFile = Loader.extractResource(getClass(),
-  
-            "/org/bytedeco/javacv/facepreview/haarcascade_frontalface_alt.xml",
-  
-            context.getCacheDir(), "classifier", ".xml");
+  
+                "/org/bytedeco/javacv/facepreview/haarcascade_frontalface_alt.xml",
+  
+                context.getCacheDir(), "classifier", ".xml");
        if (classifierFile == null || classifierFile.length() <= 0) {
            throw new IOException("Could not extract the classifier file from Java resource.");
        }
-  
-        // Preload the opencv_objdetect module to work around a known bug.
-  
-        Loader.load(opencv_objdetect.class);
-  
-        classifier = new CvHaarClassifierCascade(cvLoad(classifierFile.getAbsolutePath()));
+  
+        classifier = new CascadeClassifier(classifierFile.getAbsolutePath());
        classifierFile.delete();
        if (classifier.isNull()) {
            throw new IOException("Could not load the classifier file.");
        }
-  
-        storage = CvMemStorage.create();
    }
    public void onPreviewFrame(final byte[] data, final Camera camera) {
@@ -149,16 +143,16 @@ public void onPreviewFrame(final byte[] data, final Camera camera) {
    }
    protected void processImage(byte[] data, int width, int height) {
-  
-        // First, downsample our image and convert it into a grayscale IplImage
+  
+        // First, downsample our image and convert it into a grayscale Mat
        int f = SUBSAMPLING_FACTOR;
-  
-        if (grayImage == null || grayImage.width() != width/f || grayImage.height() != height/f) {
-  
-            grayImage = IplImage.create(width/f, height/f, IPL_DEPTH_8U, 1);
+  
+        if (grayImage == null || grayImage.cols() != width/f || grayImage.rows() != height/f) {
+  
+            grayImage = new Mat(height/f, width/f, CV_8UC1);
        }
-  
-        int imageWidth  = grayImage.width();
-  
-        int imageHeight = grayImage.height();
+  
+        int imageWidth  = grayImage.cols();
+  
+        int imageHeight = grayImage.rows();
        int dataStride = f*width;
-  
-        int imageStride = grayImage.widthStep();
-  
-        ByteBuffer imageBuffer = grayImage.getByteBuffer();
+  
+        int imageStride = grayImage.step(0);
+  
+        ByteBuffer imageBuffer = grayImage.createBuffer();
        for (int y = 0; y < imageHeight; y++) {
            int dataLine = y*dataStride;
            int imageLine = y*imageStride;
@@ -167,9 +161,8 @@ protected void processImage(byte[] data, int width, int height) {
            }
        }
-  
-        cvClearMemStorage(storage);
-  
-        faces = cvHaarDetectObjects(grayImage, classifier, storage, 1.1, 3,
-  
-                CV_HAAR_FIND_BIGGEST_OBJECT | CV_HAAR_DO_ROUGH_SEARCH);
+  
+        faces = new RectVector();
+  
+        classifier.detectMultiScale(grayImage, faces);
        postInvalidate();
    }
@@ -186,11 +179,11 @@ protected void onDraw(Canvas canvas) {
        if (faces != null) {
            paint.setStrokeWidth(2);
            paint.setStyle(Paint.Style.STROKE);
-  
-            float scaleX = (float)getWidth()/grayImage.width();
-  
-            float scaleY = (float)getHeight()/grayImage.height();
-  
-            int total = faces.total();
-  
-            for (int i = 0; i < total; i++) {
-  
-                CvRect r = new CvRect(cvGetSeqElem(faces, i));
+  
+            float scaleX = (float)getWidth()/grayImage.cols();
+  
+            float scaleY = (float)getHeight()/grayImage.rows();
+  
+            long total = faces.size();
+  
+            for (long i = 0; i < total; i++) {
+  
+                Rect r = faces.get(i);
                int x = r.x(), y = r.y(), w = r.width(), h = r.height();
                canvas.drawRect(x*scaleX, y*scaleY, (x+w)*scaleX, (y+h)*scaleY, paint);
            }
@@ -221,7 +214,7 @@ public void surfaceCreated(SurfaceHolder holder) {
        // to draw.
        mCamera = Camera.open();
        try {
-  
-           mCamera.setPreviewDisplay(holder);
+  
+            mCamera.setPreviewDisplay(holder);
        } catch (IOException exception) {
            mCamera.release();
            mCamera = null;