Android相机扭曲图像

Question

Android中的相机API存在很大问题。我想在SurfaceView中开始相机预览。这样可行。但是预览图像是distordet。为什么会发生这种解决方案？

我在App Store中有一款像Retro Camera这样的应用。所以我想在矩形或正方形中预览相机。但是预览没有正确的解决方案。

我的代码：

public class CameraActivity extends Activity implements SurfaceHolder.Callback {

Camera camera;

SurfaceView surfaceView;

SurfaceHolder surfaceHolder;

boolean previewing = false;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    ImageView buttonStartCameraPreview = (ImageView)findViewById(R.id.scanning);
    ImageView buttonStopCameraPreview = (ImageView)findViewById(R.id.buttonBack);

    getWindow().setFormat(PixelFormat.UNKNOWN);
    surfaceView = (SurfaceView)findViewById(R.id.surfaceView);
    surfaceHolder = surfaceView.getHolder();
    surfaceHolder.addCallback(this);
    surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

    buttonStartCameraPreview.setOnClickListener(
            new Button.OnClickListener() {

                @Override
                public void onClick(View v) {
                    if(!previewing) {
                        camera = Camera.open();
                        if(camera != null) {
                            try {
                                camera.setDisplayOrientation(90);
                                camera.setPreviewDisplay(surfaceHolder);
                                camera.startPreview();
                                previewing = true;
                            }
                            catch(IOException e) {
                                e.printStackTrace();
                            }
                        }
                    }
                }
            }
    );

    buttonStopCameraPreview.setOnClickListener(
            new Button.OnClickListener() {

                @Override
                public void onClick(View v) {
                    if(camera != null && previewing) {
                        camera.stopPreview();
                        camera.release();
                        camera = null;

                        previewing = false;
                    }
                }
            }
    );
}


@Override
public void surfaceChanged(
        SurfaceHolder holder, int format, int width, int height) {
}

@Override
public void surfaceCreated(SurfaceHolder holder) {
}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
}
 }

结果：
我有一个正方形，但预览是一个矩形。