オプティカルフローのサンプルがないよ！ということで作ってみました。
苦戦されている方どうぞ。
package org.opencv.samples.tutorial1;
// Java
import java.util.List;
import java.util.Vector;
// OpenCV
import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewFrame;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Size;
import org.opencv.core.Mat;
import org.opencv.core.MatOfByte;
import org.opencv.core.MatOfFloat;
import org.opencv.core.MatOfInt;
import org.opencv.core.MatOfPoint;
import org.opencv.core.MatOfPoint2f;
import org.opencv.core.MatOfPoint3f;
import org.opencv.core.Point;
import org.opencv.core.Point3;
import org.opencv.core.Rect;
import org.opencv.core.Scalar;
import org.opencv.core.TermCriteria;
import org.opencv.features2d.Features2d;
import org.opencv.imgproc.Imgproc;
import org.opencv.objdetect.CascadeClassifier;
import org.opencv.video.Video;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewListener2;
// UI
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SurfaceView;
import android.view.WindowManager;
import android.widget.Toast;
public class Tutorial1Activity extends Activity implements CvCameraViewListener2 {
private static final String TAG = "OCVSample::Activity";
// カメラ
private CameraBridgeViewBase mOpenCvCameraView;
// カメラ画像
private Mat image, image_small;
// オプティカルフロー用
private Mat image_prev, image_next;
private MatOfPoint2f pts_prev, pts_next;
// OpenCVライブラリのロード
private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
@Override
public void onManagerConnected(int status) {
switch (status) {
case LoaderCallbackInterface.SUCCESS: {
Log.i(TAG, "OpenCV loaded successfully");
mOpenCvCameraView.enableView();
break;
}
default: {
super.onManagerConnected(status);
break;
}
}
}
};
// コンストラクタ
public Tutorial1Activity() {
Log.i(TAG, "Instantiated new " + this.getClass());
pts_prev = new MatOfPoint2f();
pts_next = new MatOfPoint2f();
}
// 起動時
@Override
public void onCreate(Bundle savedInstanceState) {
Log.i(TAG, "called onCreate");
super.onCreate(savedInstanceState);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setContentView(R.layout.tutorial1_surface_view);
mOpenCvCameraView = (CameraBridgeViewBase) findViewById(R.id.tutorial1_activity_java_surface_view);
mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);
mOpenCvCameraView.setCvCameraViewListener(this);
}
// 停止時
@Override
public void onPause() {
super.onPause();
if (mOpenCvCameraView != null) mOpenCvCameraView.disableView();
}
// 再開時
@Override
public void onResume() {
super.onResume();
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_3, this, mLoaderCallback);
}
// 破棄時
public void onDestroy() {
super.onDestroy();
if (mOpenCvCameraView != null) mOpenCvCameraView.disableView();
}
// カメラ開始時
public void onCameraViewStarted(int width, int height) {
image = new Mat(height, width, CvType.CV_8UC3);
image_small = new Mat(height/8, width/8, CvType.CV_8UC3);
image_prev = new Mat(image_small.rows(), image_small.cols(), image_small.type());
image_next = new Mat(image_small.rows(), image_small.cols(), image_small.type());
}
// カメラ停止時
public void onCameraViewStopped() {
}
// 画像取得時
public Mat onCameraFrame(CvCameraViewFrame inputFrame) {
// 縮小
image = inputFrame.rgba();
Imgproc.resize(image, image_small, image_small.size(), 0, 0, Imgproc.INTER_NEAREST);
// グレースケール
Mat gray = new Mat(image_small.rows(), image_small.cols(), CvType.CV_8UC1);
Imgproc.cvtColor(image_small, gray, Imgproc.COLOR_RGB2GRAY);
// 特徴点抽出
MatOfPoint features = new MatOfPoint();
Imgproc.goodFeaturesToTrack(gray, features, 50, 0.01, 10);
// 特徴点が見つかった
if (features.total() > 0) {
// 過去のデータが存在する
if (pts_prev.total() > 0) {
// 現在のデータ
gray.copyTo(image_next);
pts_next = new MatOfPoint2f(features.toArray());
// オプティカルフロー算出
MatOfByte status = new MatOfByte();
MatOfFloat err = new MatOfFloat();
Video.calcOpticalFlowPyrLK(image_prev, image_next, pts_prev, pts_next, status, err);
// 表示
long flow_num = status.total();
if (flow_num > 0) {
List<Byte> list_status = status.toList();
List<Point> list_features_prev = pts_prev.toList();
List<Point> list_features_next = pts_next.toList();
double scale_x = image.cols() / image_small.cols();
double scale_y = image.rows() / image_small.rows();
for (int i = 0; i < flow_num; i++) {
if (list_status.get(i) == 1) {
Point p1 = new Point();
p1.x = list_features_prev.get(i).x * scale_x;
p1.y = list_features_prev.get(i).y * scale_y;
//Core.circle(image, p1, 3, new Scalar(255,0,0), -1, 8, 0 );
Point p2 = new Point();
p2.x = list_features_next.get(i).x * scale_x;
p2.y = list_features_next.get(i).y * scale_y;
//Core.circle(image, p2, 3, new Scalar(255,255,0), -1, 8, 0 );
// フロー描画
int thickness = 5;
Core.line(image, p1, p2, new Scalar(0,255,0), thickness);
}
}
}
}
// 過去のデータ
gray.copyTo(image_prev);
pts_prev = new MatOfPoint2f(features.toArray());
}
return image;
}
}
オプティカルフローできるからどうしたという話ですが、動きベクトルが表示されると楽しいですよね。
