Fabric JS still including default values

Fabric JS still including default values

I tried to set the includeDefaultValues:false every time I create an
object, however, the save string for an image is still:
[{"type":"image","originX":"center","originY":"center","left":396.16,"top":108.16,"width":2475,"height":675,"fill":"rgb(0,0,0)","overlayFill":null,"stroke":null,"strokeWidth":1,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":0.32,"scaleY":0.32,"angle":0,"flipX":false,"flipY":false,"opacity":1,"selectable":true,"hasControls":true,"hasBorders":true,"hasRotatingPoint":true,"transparentCorners":true,"perPixelTargetFind":false,"shadow":null,"visible":true,"clipTo":null,"src":"http://localhost/fabricjstest/designs/images/ds130814014834.png?t=1376502517","filters":[]}],"background":"#FFF"}
I am pretty sure most of those are default values, so how can I get it to
work? Maybe I am saving wrong, so this is my save code:
var obj = canvas.toObject();
var jsn = JSON.stringify(obj);
alert(jsn);
Here is the version directly from the js file: var
fabric=fabric||{version:"1.2.9"};
So the question is: How do I disable default values.