Go back: edge

Currently: edge = all detected pixel edges
Risk: Some of them are on the same theoretical angular position, so the extracted edge is distorted (extended, spread out)
Solution:

• Don't take every point;
• Make our sampling a 2-phase process:
  
• Phase 1: the edge extraction uses a strict pixel-precision sampling, i.e., the angular sampling rate is limited to 1-pixel wide, so that at each pixel angular position, no two points exist in our edge array.
• Phase 2: audio re-sampling

Plan: don't do this until we hear the sound.