使用openframeworks,OpenCV和Box2D,我能够以良好的帧速率实现它.使用
Android似乎是一项更复杂的任务(部分原因是我是JAVA新手).
这就是我的开始：
>使用“OpenCV示例 – 图像处理”并删除除“canny”效果之外的所有内容,这会产生一个漂亮的黑色&白色图像,非常适合找到轮廓.
public Mat onCameraFrame(CvCameraviewFrame inputFrame)
{
mRgba = inputFrame.rgba();
Imgproc.Canny(mRgbaInnerWindow,mIntermediateMat,50,100);
Imgproc.cvtColor(mIntermediateMat,mRgbaInnerWindow,Imgproc.COLOR_GRAY2BGRA,4);
return mRgba;
}
>从“OpenCV Sample – color-blob-detection”中我抓住了在Mat中找到轮廓的逻辑：
// These two lines are actually in the function onCameraviewStarted mHierarchy = new Mat(); CONTOUR_COLOR = new Scalar(255,255); // These lines are in function onCameraFrame List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Imgproc.findContours(mRgbaInnerWindow,contours,mHierarchy,Imgproc.RETR_EXTERNAL,Imgproc.CHAIN_APPROX_SIMPLE); Imgproc.drawContours(mIntermediateMat,-1,CONTOUR_COLOR);
所以,我当前的函数看起来像这样,它不起作用：
public Mat onCameraFrame(CvCameraviewFrame inputFrame)
{
mRgba = inputFrame.rgba();
if ((mRgbaInnerWindow == null) || (mGrayInnerWindow == null) || (mRgba.cols() != mSizeRgba.width) || (mRgba.height() != mSizeRgba.height))
CreateAuxiliaryMats();
Imgproc.Canny(mRgbaInnerWindow,100);
//Imgproc.cvtColor(mIntermediateMat,4);
List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
Imgproc.findContours(mRgbaInnerWindow,Imgproc.CHAIN_APPROX_SIMPLE);
//Imgproc.drawContours(mIntermediateMat,CONTOUR_COLOR);
return mRgba;
}
>现在,这就是我被困的地方.我不断得到例外,我认为我没有使用正确的尺寸或将Mat转换为正确的颜色空间.这篇文章有一些见解,但我不知道它是否正确：OpenCV on Android findContours throws Exception
解决方法
嗨我也是openCV的新手,不过这段代码可能有帮助,
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.SurfaceView;
import org.opencv.android.*;
import org.opencv.core.*;
import org.opencv.imgproc.Imgproc;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends Activity implements CvCameraviewListener2{
private static final String TAG = MainActivity.class.getCanonicalName();
private CameraBridgeViewBase mOpenCvCameraview;
private Mat mRgba;
private Mat mIntermediateMat;
private Mat mGray;
Mat hierarchy;
List<MatOfPoint> contours;
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;
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mOpenCvCameraview = (CameraBridgeViewBase) findViewById(R.id.java_surface_view);
mOpenCvCameraview.setVisibility(SurfaceView.VISIBLE);
mOpenCvCameraview.setCvCameraviewListener(this);
}
@Override
public void onResume() {
super.onResume();
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_3,this,mloaderCallback);
}
@Override
public void onPause() {
super.onPause();
if (mOpenCvCameraview != null)
mOpenCvCameraview.disableView();
}
@Override
public void onCameraviewStarted(int width,int height) {
mRgba = new Mat(height,width,CvType.CV_8UC4);
mIntermediateMat = new Mat(height,CvType.CV_8UC4);
mGray = new Mat(height,CvType.CV_8UC1);
hierarchy = new Mat();
}
@Override
public void onCameraviewStopped() {
mRgba.release();
mGray.release();
mIntermediateMat.release();
hierarchy.release();
}
@Override
public Mat onCameraFrame(CvCameraviewFrame inputFrame) {
mRgba = inputFrame.gray();
contours = new ArrayList<MatOfPoint>();
hierarchy = new Mat();
Imgproc.Canny(mRgba,80,100);
Imgproc.findContours(mIntermediateMat,hierarchy,Imgproc.RETR_TREE,Imgproc.CHAIN_APPROX_SIMPLE,new Point(0,0));
/* Mat drawing = Mat.zeros( mIntermediateMat.size(),CvType.CV_8UC3 );
for( int i = 0; i< contours.size(); i++ )
{
Scalar color =new Scalar(Math.random()*255,Math.random()*255,Math.random()*255);
Imgproc.drawContours( drawing,i,color,2,8,new Point() );
}*/
hierarchy.release();
Imgproc.drawContours(mRgba,new Scalar(Math.random()*255,Math.random()*255));//,new Point());
// Imgproc.cvtColor(mIntermediateMat,mRgba,Imgproc.COLOR_GRAY2RGBA,4);
return mRgba;
}
}
我知道这可能不是实现这一目标的最佳方式,但我们都在这里学习新方法:)