相机预览被拉伸和倾斜

Question

如何在相机预览中解决图像的拉伸问题？

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();

    }
}

Answer 1

也许您的CameraView的宽高比与相机预览尺寸的宽高比不匹配。 您应该计算CameraView的宽高比并使用此宽高比来查找Camera.Parameters.setPreviewSize()方法的最佳大小。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);
}