Android : Android: Take photo without preview: java.lang.RuntimeException: takePicture failed

I get a java.lang.RuntimeException: takePicture failed for the following Android code:

public class TakePicture {
Camera camera;
Parameters parameters;
Context context;
public TakePicture(Context context)
{
    camera = Camera.open();
    this.context=context;
    parameters = camera.getParameters();
    parameters.setPictureFormat(PixelFormat.JPEG);
    camera.setParameters(parameters);

    SurfaceView sview = new SurfaceView(context);
    try {
        camera.setPreviewDisplay(sview.getHolder());
        camera.startPreview();
        camera.takePicture(null,null,photoCallback);
    } catch (IOException e) {
        e.printStackTrace();
    }
    catch(Exception e)
    {
        e.printStackTrace();
    }


}

PictureCallback photoCallback=new PictureCallback() {
    public void onPictureTaken(byte[] data, Camera camera) {
        //...
    }
};

}

I simply wanted to take a photo with the front camera without a preview and save it afterwords.

An instance of this class is created in the Main Activity with this code:

TakePicture tp = new TakePicture(this);

Do you have any suggestions how to solve this?

Thanks in advance!