Export frame as image

An exportImage method that returns image data (png, etc) for the current wavesurfer frame would be useful.

[chrisparton1991]

@thijstriemstra, I don’t know how feasible it is to add this to MultiCanvas. I’d need to get the data URLs from each canvas and stitch them together.

I’ve done some googling, and it seems the way to do this is typically to redraw the data URLs from each canvas onto a separate canvas, then re-export that canvas as a data URL. However, since the point of MultiCanvas is to overcome the size limitations of a single canvas, there wouldn’t be much benefit to doing this. Thoughts?

[thijstriemstra]

@usfslk read the docs at https://wavesurfer-js.org/api/class/src/wavesurfer.js~WaveSurfer.html#instance-method-exportImage