How to make emgucv saliency algorithm work?

I try to pass an image to the emgucv saliency algorithm but it doesn't seem to work. The result will become a blank black box.

Please..

Emgu.CV.Saliency.StaticSaliencySpectralResidual test = new Emgu.CV.Saliency.StaticSaliencySpectralResidual();
var img = new Image<Bgr, Byte>(@"C:\Users\jb\Desktop\3800233070071.jpg");

var mask = new Mat();
bool test2=Emgu.CV.Saliency.SaliencyInvoke.Compute(test, img, mask);
mask.Save("saliency.jpg");