I would love some inputs in what's the best way to achieve an effective edge detection of an image.

The method I have in mind is to apply Canny operator on an image, from there I would like to  store white pixels / the edge point (coordinates) in an array/list and then go through these points and calculates the density of the points. 

I was wondering if it's possible to scan an image (as in left to right & top to bottom) and do the method mentioned ? 

If I could achieve that then I would like to translate the edges into sound.

Any suggestion for the best way to achieve this?