Create a Path2D from ImageData in JavaScript

Given an ImageData object, is there a function or algorithm to create a Path2D that contains all non-transparent pixels?

For background, I have a low-resolution, raster image that will be used as a mask for some higher-resolution, dynamic content. While I can accomplish this goal using a temporary canvas and various globalCompositeOperation types, I would prefer to use clip() with a path – I suspect it will be more efficient. The mask image does not change often, so the path can be re-used many times once it has been calculated.