Paper js, как отключить сглаживание при zoom'e?

var upscaledCanvas = document.getElementById('upscaledcanvas').getContext('2d');
upscaledCanvas.mozImageSmoothingEnabled = false;
upscaledCanvas.webkitImageSmoothingEnabled = false;
upscaledCanvas.msImageSmoothingEnabled = false;
upscaledCanvas.imageSmoothingEnabled = false;