How to get image itselfs?

I'm making xamarin apps application and I want to edit images with it. How can I get image to make some work with it? (I want to edit some pixels)

        var result = await MediaPicker.PickPhotoAsync(new MediaPickerOptions()
        {
            Title = "Выберите изображение" //Eng: Pick image
        });

        var stream = await result.OpenReadAsync();

        image.Source = ImageSource.FromStream(() => stream);