public void ConvertGrayscale()
{
var layer = new Layer(_image, "test", ImageType.Rgb);
_image.InsertLayer(layer, 0);
var type = _image.BaseType;
_image.ConvertGrayscale();
Assert.IsTrue(_image.BaseType == ImageBaseType.Gray);
// Fix me: find out why next assert fails!
// Assert.Equals(ImageBaseType.Gray, _image.BaseType);
}