相机预览被拉伸和倾斜

Posted 2023-04-17

【中文标题】相机预览被拉伸和倾斜

【英文标题】：Camera Preview is stretched and skewed

【发布时间】：2016-08-12 21:35:35

【问题描述】：

如何解决我的相机预览中的图像拉伸问题？

相机预览类

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback  
private SurfaceHolder mHolder; 
private Camera mCamera;

public class CameraPreview extends SurfaceView implements
        SurfaceHolder.Callback 
    private SurfaceHolder mHolder;
    private Camera mCamera;

    public CameraPreview(Context context, Camera camera) 
        super(context);
        mCamera = camera;
        mHolder = getHolder();
        mHolder.addCallback(this);
        // deprecated setting, but required on android versions prior to 3.0
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    

    public void surfaceCreated(SurfaceHolder holder) 
        try 
            // create the surface and start camera preview
            if (mCamera == null) 
                mCamera.setPreviewDisplay(holder);
                mCamera.startPreview();
            
         catch (IOException e) 
            Log.d(VIEW_LOG_TAG,
                    "Error setting camera preview: " + e.getMessage());
        
    

    public void refreshCamera(Camera camera) 
        if (mHolder.getSurface() == null) 
            // preview surface does not exist
            return;
        
        // stop preview before making changes
        try 
            mCamera.stopPreview();
         catch (Exception e) 
            // ignore: tried to stop a non-existent preview
        
        // set preview size and make any resize, rotate or
        // reformatting changes here
        // start preview with new settings
        setCamera(camera);
        try 
            mCamera.setPreviewDisplay(mHolder);
            mCamera.startPreview();
         catch (Exception e) 
            Log.d(VIEW_LOG_TAG,
                    "Error starting camera preview: " + e.getMessage());
        
    

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) 
        // If your preview can change or rotate, take care of those events here.
        // Make sure to stop the preview before resizing or reformatting it.
        refreshCamera(mCamera);
    

    public void setCamera(Camera camera) 
        // method to set a camera instance
        mCamera = camera;
    

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) 
        // TODO Auto-generated method stub
        // mCamera.release();

    

【问题讨论】：

注意在 Grafika 中使用 AspectFrameLayout，例如“连续捕获”（github.com/google/grafika/blob/master/src/com/android/grafika/…）。 FWIW，当您的图像被拉伸时，我会很惊讶它被歪斜，因为源和目标都是矩形。

【参考方案1】：

可能您的 CameraView 的纵横比与相机预览大小的纵横比不匹配。 您应该计算您的 CameraView 的纵横比并使用此纵横比来找到 Camera.Parameters.setPreviewSize() 方法的最佳尺寸。 试试这个

private Camera.Size getBestPreviewSize(Camera.Parameters parameters, int width, int height) 
    Camera.Size result = null;
    double ratio = width / height;
    double w = 0, h = 0;
    for (Camera.Size size : parameters.getSupportedPreviewSizes()) 
        w = size.width;
        h = size.height;
        if (w / h == ratio) 
            if (result != null) 
                if (w > result.width) 
                    result = size;
                
             else 
                result = size;
            
        

    
    return (result);

【讨论】：

在哪里调用这个方法？以及如何检查我的预览的大小？

首先，您需要在开始预览之前调用该方法。您可以搜索“如何设置我的相机预览大小”以查看步骤。其次，您的预览大小是您在屏幕上显示的 SurfaceView 的大小。最后，fadden 的建议是另一种方式。