[Question] How to pan and zoom and change the stroke color to black?

[RukshanJS]

1. When zoomed in, the quality of the puzzle pieces is highly reduced - is there any way to minimize this loss - and perform zoom and pan? I tried several methods with the default canvas but they all have either performance issues or messes the puzzle drawing mechanism.
2. How to change the stroke color to say black? - couldn't find a straightforward way to do this.

UPDATE: It seems the quality of the pieces and outline are dependant on the image quality. Can we make it not so?

UPDATE 2 : I got the 2nd one working (stroke is now customizable) after some tweaking. Regarding question 2 still, if I use the scale() property to zoom in/out, then the puzzle pieces are blurred.