CameraView 中的人像模式

Posted 2023-04-17

【中文标题】CameraView 中的人像模式

【英文标题】：Portrait mode in CameraView

【发布时间】：2013-08-31 21:28:42

【问题描述】：

我将使用 BeyondAR 框架开发一个 android 应用程序。我尝试在屏幕的前半部分使用 CameraView 组件（应用程序仅在纵向模式下运行），但是当我将相机旋转 90 度时，图像拉伸并且纵横比错误。有帮助吗？

CameraView 类（Beyondar 框架）

public class CameraView extends SurfaceView implements SurfaceHolder.Callback,
    Camera.PictureCallback 

/**
 * 
 * @author Joan Puig Sanz ([e-mail])
 * 
 */
public static interface IPictureCallback 
    /**
     * This method is called when the snapshot of the camera is ready. If
     * there is an error, the image will be null
     * 
     * @param picture
     */
    void onPictureTaken(Bitmap picture);


private SurfaceHolder mHolder;
private Camera mCamera;
private IPictureCallback mCameraCallback;
private BitmapFactory.Options mOptions;

private Size mPreviewSize;
private List<Size> mSupportedPreviewSizes;
private List<String> mSupportedFlashModes;

public CameraView(Context context) 
    super(context);
    init(context);


public CameraView(Context context, AttributeSet attrs, int defStyle) 
    super(context, attrs, defStyle);
    init(context);


public CameraView(Context context, AttributeSet attrs) 
    super(context, attrs);
    init(context);


private void init(Context context) 
    mHolder = getHolder();
    mHolder.addCallback(this);

    try 
        mCamera = Camera.open();
        //mCamera.setDisplayOrientation(90);


        //Camera.Parameters params = mCamera.getParameters();
        //params.setPreviewSize(427, 1240); 
        //mCamera.setParameters(params);
        setCamera(mCamera);
     catch (Exception e) 
        Log.e(Constants.TAG, "ERROR: Unable to open the camera", e);
    

    if (android.os.Build.VERSION.SDK_INT <= 10) // Android 2.3.x or lower
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    


public void setCamera(Camera camera) 
    mCamera = camera;
    if (mCamera != null) 
        mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
        mSupportedFlashModes = mCamera.getParameters().getSupportedFlashModes();
        // Set the camera to Auto Flash mode.
        if (mSupportedFlashModes != null
                && mSupportedFlashModes.contains(Camera.Parameters.FLASH_MODE_AUTO)) 
            Camera.Parameters parameters = mCamera.getParameters();
            parameters.setFlashMode(Camera.Parameters.FLASH_MODE_AUTO);
            //parameters.setPreviewSize(300, 200);
            mCamera.setParameters(parameters);
        
    


public void setSupportedPreviewSizes(List<Size> supportedPreviewSizes) 
    mSupportedPreviewSizes = supportedPreviewSizes;


public Size getPreviewSize() 
    return mPreviewSize;


public void surfaceCreated(SurfaceHolder holder) 
    // The Surface has been created, acquire the camera and tell it where
    // to draw.
    try 

        if (mCamera == null) 
            init(getContext());
            if (mCamera == null) 
                return;
            
        

        mCamera.setPreviewDisplay(holder);
     catch (IOException exception) 
        if (mCamera != null) 
            mCamera.release();
        
        mCamera = null;
        Log.e(Constants.TAG, "CameraView -- ERROR en SurfaceCreated", exception);
    


public void surfaceDestroyed(SurfaceHolder holder) 
    // Surface will be destroyed when we return, so stop the preview.
    // Because the CameraDevice object is not a shared resource, it's very
    // important to release it when the activity is paused.
    if (mCamera == null) 
        return;
    
    mCamera.stopPreview();
    mCamera.release();
    mCamera = null;


@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) 
    final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
    final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
    setMeasuredDimension(width, height);

    if (mSupportedPreviewSizes != null) 
        mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
    

    super.onMeasure(widthMeasureSpec, heightMeasureSpec);


private Size getOptimalPreviewSize(List<Size> sizes, int width, int height) 

    Size result = null;

    for (Camera.Size size : sizes) 
        if (size.width <= width && size.height <= height) 
            if (result == null) 
                result = size;
             else 
                int resultArea = result.width * result.height;
                int newArea = size.width * size.height;

                if (newArea > resultArea) 
                    result = size;
                
            
        
    

    return result;


public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) 
    if (mCamera == null || getPreviewSize() == null) 
        return;
    

    Camera.Parameters parameters = mCamera.getParameters();
    Size previewSize = getPreviewSize();
    parameters.setPreviewSize(previewSize.width, previewSize.height);

    mCamera.setParameters(parameters);
    previewCamera();



@Override
public void onPictureTaken(byte[] imageData, Camera camera) 
    if (imageData != null && mCameraCallback != null) 
        mCameraCallback.onPictureTaken(StoreByteImage(imageData));
    
    previewCamera();


public void previewCamera() 
    if (mCamera == null)
        return;
    
    try 
        mCamera.setPreviewDisplay(mHolder);
        mCamera.startPreview();
     catch (Exception e) 
        Log.d(Constants.TAG, "Cannot start preview.", e);
    


private Bitmap StoreByteImage(byte[] imageData) 

    Bitmap myImage = DebugBitmap.decodeByteArray(imageData, 0, imageData.length, mOptions);

    imageData = null;
    System.gc();

    return myImage;


public void tackePicture(IPictureCallback cameraCallback) 
    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inSampleSize = 4;
    tackePicture(cameraCallback, options);


public void tackePicture(IPictureCallback cameraCallback, BitmapFactory.Options options) 
    if (mCamera == null) 
        return;
    
    mCameraCallback = cameraCallback;
    mCamera.takePicture(null, this, this);
    mOptions = options;

编辑

MyLayout xml 文件

  <LinearLayout
    android:layout_
    android:layout_
    android:layout_weight="1"
    android:orientation="horizontal"
    android:paddingBottom="@dimen/padding"
    android:paddingLeft="@dimen/padding"
    android:paddingRight="@dimen/padding"
    android:paddingTop="@dimen/padding" >  

    <FrameLayout 
   android:orientation="vertical"
   android:layout_
   android:layout_
   >
    <com.beyondar.android.opengl.views.BeyondarGLSurfaceView
    android:id="@+id/customGLSurface"
    android:layout_ 
    android:layout_ />    
    <com.beyondar.android.views.CameraView 
    android:id="@+id/camera"
    android:layout_ 
    android:layout_ />

<TextView  
    android:id="@+id/labelText"
    android:layout_ 
    android:layout_ 
    android:text="Touch an AR Object"
    android:background="#000000"
    android:textColor="#FFFFFF"
    />


    </FrameLayout>
   </LinearLayout

【问题讨论】：

您说“应用程序仅在纵向模式下运行”，您的意思是您已经在自己处理旋转并将 Activity 限制为纵向模式？

是的！但是相机视图有横向模式！这就是问题所在！

【参考方案1】：

如果您查看 BeyondAR 的示例应用程序，您会发现它有一个类似的问题，即相机的图像被拉伸以填满屏幕，因此在横向和纵向的两种情况下都没有适当的纵横比。这是使用相机预览时的常见问题，因为它在您首次启动时锁定到特定方向。

为了实现这一点，您需要将旋转视图的大小调整为与设备相机相匹配的纵横比。 Here's the official Android guide。

请注意专门称为“设置预览方向”的部分。

【讨论】：

感谢您的回答，但您能在我的代码中解释一下吗？对不起，我是初学者

BeyondAR 库作为 Android 库项目分发，因此您可以在将库加载到 IDE 后随意编辑该库。您使用的是什么 IDE？

eclipse...我在第一篇文章中上传了 Beyondar lib 的 cameraview.java

【参考方案2】：

BeyondAR 已更新，现在由于有了片段，它变得更容易了。检查网页并更新您的库：

https://github.com/BeyondAR/beyondar