文章/答案/技术大牛

发布

社区首页 >问答首页 >OpenCV摄像头方向问题

问OpenCV摄像头方向问题
EN

Stack Overflow用户

提问于 2013-05-21 20:15:05

回答 7查看 33.6K关注 0票数 16

我有一个简单的项目，只显示相机与org.opencv.android.JavaCameraView。

我的问题是，在默认情况下，相机处于横向模式，我无法更改这一点，因为我需要定义CameraBridgeViewBase而不是常规的相机意图。

这是我的代码的一部分：

XML代码：

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent" >

            <org.opencv.android.JavaCameraView
                android:layout_width="fill_parent"
                android:layout_height="300dp"
                android:visibility="gone"
                android:id="@+id/HelloOpenCvView"
                opencv:show_fps="true"
                opencv:camera_id="1" />


        </LinearLayout>  

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content" >


            <Button
                android:id="@+id/BtnVideo"
                android:layout_marginLeft="2dp"
                android:layout_marginRight="2dp"                    
                android:layout_width="0dp"
                style="@style/button"
                android:layout_height="wrap_content"
                android:layout_weight="1.00"
                android:text="@string/videoBtn"
                android:textSize="18dip" />


        </LinearLayout>

Java代码：

 CameraBridgeViewBase mOpenCvCameraView;
    Button VideoButton;
 protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        overridePendingTransition(0, 0);

        VideoButton = (Button) this.findViewById(R.id.BtnVideo);

        VideoButton.setOnClickListener(onClickListener);

        mOpenCvCameraView= (CameraBridgeViewBase) findViewById(R.id.HelloOpenCvView);
        mOpenCvCameraView.setVisibility(SurfaceView.INVISIBLE);

    } 

        private OnClickListener onClickListener = new OnClickListener() {

            @Override
            public void onClick(View v) {
                    switch (v.getId()){

                        case R.id.BtnVideo:
                            if(mOpenCvCameraView.getVisibility() == SurfaceView.VISIBLE)
                            {
                                mOpenCvCameraView.setVisibility(SurfaceView.INVISIBLE);
                            }
                            else
                            {
                                mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);
                            }

                            break;
                        default :
                            break;
                    }

            }
        };


        public void onResume() {
            super.onResume();
            overridePendingTransition(0, 0);
            OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_3, this, mLoaderCallback);
        }
         public void onPause()
         {
             super.onPause();
             if (mOpenCvCameraView != null)
                 mOpenCvCameraView.disableView();
         }
         public void onDestroy() {
             super.onDestroy();
             if (mOpenCvCameraView != null)
                 mOpenCvCameraView.disableView();
         }
         public void onCameraViewStarted(int width, int height) {
         }

         public void onCameraViewStopped() {
         }
         public Mat onCameraFrame(CvCameraViewFrame inputFrame) {
             return inputFrame.rgba();
         }

        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;
                }
            }
        };

那么我该如何更改默认方向呢？

谢谢!

android

opencv

android-orientation

回答 7

Stack Overflow用户

回答已采纳

发布于 2013-05-22 14:00:54

好的，我找到了一个解决方案：

首先，我进入OpenCV库中的JavaCameraView.java类-- 2.4.5

然后在mCamera.startPreview();之前的initializeCamera()函数中，我添加了这两个函数：

            setDisplayOrientation(mCamera, 90);
            mCamera.setPreviewDisplay(getHolder());

第一个函数实现如下：

protected void setDisplayOrientation(Camera camera, int angle){
    Method downPolymorphic;
    try
    {
        downPolymorphic = camera.getClass().getMethod("setDisplayOrientation", new Class[] { int.class });
        if (downPolymorphic != null)
            downPolymorphic.invoke(camera, new Object[] { angle });
    }
    catch (Exception e1)
    {
        e1.printStackTrace();
    }
}

我只是提醒你我是和OpenCV一起工作的。

希望这对某些人有帮助。

票数 41

Stack Overflow用户

发布于 2015-12-31 13:30:28

我使用的是OpenCV 3.1，我通过在CameraBridgeViewBase类的deliverAndDrawFrame方法上绘制位图时应用变换来修复它，希望它能有所帮助：

在CameraBridgeViewBase.java上：

//I added new field
private final Matrix mMatrix = new Matrix();

//added updateMatrix method 
private void updateMatrix() {
    float hw = this.getWidth() / 2.0f;
    float hh = this.getHeight() / 2.0f;
    boolean isFrontCamera = Camera.CameraInfo.CAMERA_FACING_FRONT == mCameraIndex;
    mMatrix.reset();
    if (isFrontCamera) {
        mMatrix.preScale(-1, 1, hw, hh);
    }
    mMatrix.preTranslate(hw, hh);
    if (isFrontCamera)
        mMatrix.preRotate(270);
    else
        mMatrix.preRotate(90);
    mMatrix.preTranslate(-hw, -hh);
}

//then We need call updateMatrix on layout
@Override
public void layout(int l, int t, int r, int b) {
    super.layout(l, t, r, b);
    updateMatrix();
}

//I think we should also call updateMatrix on measure
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    updateMatrix();
}


//then We need update deliverAndDrawFrame
protected void deliverAndDrawFrame(CvCameraViewFrame frame) {
    //....Origin Code...

    //Set matrix before OpenCV draw bitmap
    int saveCount = canvas.save();
    canvas.setMatrix(mMatrix);

    //Begin OpenCv origin source
    if (mScale != 0) {
        canvas.drawBitmap(mCacheBitmap, new Rect(0,0,mCacheBitmap.getWidth(), mCacheBitmap.getHeight()),
             new Rect((int)((canvas.getWidth() - mScale*mCacheBitmap.getWidth()) / 2),
             (int)((canvas.getHeight() - mScale*mCacheBitmap.getHeight()) / 2),
             (int)((canvas.getWidth() - mScale*mCacheBitmap.getWidth()) / 2 + mScale*mCacheBitmap.getWidth()),
             (int)((canvas.getHeight() - mScale*mCacheBitmap.getHeight()) / 2 + mScale*mCacheBitmap.getHeight())), null);
    } else {
         canvas.drawBitmap(mCacheBitmap, new Rect(0,0,mCacheBitmap.getWidth(), mCacheBitmap.getHeight()),
             new Rect((canvas.getWidth() - mCacheBitmap.getWidth()) / 2,
             (canvas.getHeight() - mCacheBitmap.getHeight()) / 2,
             (canvas.getWidth() - mCacheBitmap.getWidth()) / 2 + mCacheBitmap.getWidth(),
             (canvas.getHeight() - mCacheBitmap.getHeight()) / 2 + mCacheBitmap.getHeight()), null);
    }
    //End OpenCv origin source

    //Restore canvas after draw bitmap
    canvas.restoreToCount(saveCount);

    //....Origin code...
}



//After that We can see that the camera preview is so small, the easiest way is change mScale Value (should we change mScale to "private" instead "protected" ?)
protected void deliverAndDrawFrame(CvCameraViewFrame frame) {
    //....Origin Code...

    //Set matrix before OpenCV draw bitmap to screen
    int saveCount = canvas.save();
    canvas.setMatrix(mMatrix);


    //Change mScale to "Aspect to fill"
    mScale = Math.max((float) canvas.getHeight() / mCacheBitmap.getWidth(), (float) canvas.getWidth() / mCacheBitmap.getHeight());

    //Begin OpenCv origin source
    if (mScale != 0) {
        canvas.drawBitmap(mCacheBitmap, new Rect(0,0,mCacheBitmap.getWidth(), mCacheBitmap.getHeight()),
             new Rect((int)((canvas.getWidth() - mScale*mCacheBitmap.getWidth()) / 2),
             (int)((canvas.getHeight() - mScale*mCacheBitmap.getHeight()) / 2),
             (int)((canvas.getWidth() - mScale*mCacheBitmap.getWidth()) / 2 + mScale*mCacheBitmap.getWidth()),
             (int)((canvas.getHeight() - mScale*mCacheBitmap.getHeight()) / 2 + mScale*mCacheBitmap.getHeight())), null);
    } else {
         canvas.drawBitmap(mCacheBitmap, new Rect(0,0,mCacheBitmap.getWidth(), mCacheBitmap.getHeight()),
             new Rect((canvas.getWidth() - mCacheBitmap.getWidth()) / 2,
             (canvas.getHeight() - mCacheBitmap.getHeight()) / 2,
             (canvas.getWidth() - mCacheBitmap.getWidth()) / 2 + mCacheBitmap.getWidth(),
             (canvas.getHeight() - mCacheBitmap.getHeight()) / 2 + mCacheBitmap.getHeight()), null);
    }
    //End OpenCv origin source

    //Restore canvas after draw bitmap
    canvas.restoreToCount(saveCount);

    //....Origin Code...
}

你可以在这里获得完整的源代码：https://gist.github.com/thongdoan/d73267eb58863f70c77d1288fe5cd3a4

票数 11

Stack Overflow用户

发布于 2016-09-21 01:10:50

问题是，绘制的代码不检查相机参数。垫是在"CameraBridgeViewBase“类中的函数"deliverAndDrawFrame”中的曲面视图上绘制的。

只需在CameraBridgeViewBase类中进行非常简单的修改，我们就可以创建一个旋转绘制位图的函数。

int userRotation= 0;

public void setUserRotation(int userRotation) {
    this.userRotation = userRotation;
}

/**
 * This method shall be called by the subclasses when they have valid
 * object and want it to be delivered to external client (via callback) and
 * then displayed on the screen.
 * @param frame - the current frame to be delivered
 */
protected void deliverAndDrawFrame(CvCameraViewFrame frame) {
    Mat modified;

    if (mListener != null) {
        modified = mListener.onCameraFrame(frame);
    } else {
        modified = frame.rgba();
    }

    boolean bmpValid = true;
    if (modified != null) {
        try {
            Utils.matToBitmap(modified, mCacheBitmap);
        } catch(Exception e) {
            Log.e(TAG, "Mat type: " + modified);
            Log.e(TAG, "Bitmap type: " + mCacheBitmap.getWidth() + "*" + mCacheBitmap.getHeight());
            Log.e(TAG, "Utils.matToBitmap() throws an exception: " + e.getMessage());
            bmpValid = false;
        }
    }

    if (bmpValid && mCacheBitmap != null) {
        Canvas canvas = getHolder().lockCanvas();
        if (canvas != null) {
            canvas.drawColor(Color.parseColor("#8BC34A"), PorterDuff.Mode.SRC_IN);
 //this is the rotation part
            canvas.save();
            canvas.rotate(userRotation,  (canvas.getWidth()/ 2),(canvas.getHeight()/ 2));

            if (mScale != 0) {
                canvas.drawBitmap(mCacheBitmap, new Rect(0,0,mCacheBitmap.getWidth(), mCacheBitmap.getHeight()),
                     new Rect((int)((canvas.getWidth() - mScale*mCacheBitmap.getWidth()) / 2),
                     (int)((canvas.getHeight() - mScale*mCacheBitmap.getHeight()) / 2),
                     (int)((canvas.getWidth() - mScale*mCacheBitmap.getWidth()) / 2 + mScale*mCacheBitmap.getWidth()),
                     (int)((canvas.getHeight() - mScale*mCacheBitmap.getHeight()) / 2 + mScale*mCacheBitmap.getHeight())), null);
            } else {
                 canvas.drawBitmap(mCacheBitmap, new Rect(0,0,mCacheBitmap.getWidth(), mCacheBitmap.getHeight()),
                     new Rect((canvas.getWidth() - mCacheBitmap.getWidth()) / 2,
                     (canvas.getHeight() - mCacheBitmap.getHeight()) / 2,
                     (canvas.getWidth() - mCacheBitmap.getWidth()) / 2 + mCacheBitmap.getWidth(),
                     (canvas.getHeight() - mCacheBitmap.getHeight()) / 2 + mCacheBitmap.getHeight()), null);
            }

            if (mFpsMeter != null) {
                mFpsMeter.measure();
                mFpsMeter.draw(canvas, 20, 30);
            }
//remember to restore the canvas 
            canvas.restore();
            getHolder().unlockCanvasAndPost(canvas);
        }
    }
}

我尝试了最常见的解决方案，使用Core.flip函数旋转垫子，但消耗了大量资源，这种解决方案对检测没有影响，对性能也没有影响，只是改变了图像在画布上绘制的方式。

希望这能有所帮助。

票数 10

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/16669779

复制

相似问题

问OpenCV摄像头方向问题
EN

回答 7

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问OpenCV摄像头方向问题EN

回答 7

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问OpenCV摄像头方向问题
EN