Function _fisheyeApplyDistortion

src/utils/cameraUndistortion.ts:168–178

(uu: Vec2, i: CameraIntrinsics)

//   tangential/prism: 2D Newton (numeric Jacobian).

function _fisheyeApplyDistortion(uu: Vec2, i: CameraIntrinsics): Vec2 {
  const r2 = uu.x * uu.x + uu.y * uu.y;
  const t4 = r2 * r2;
  const t6 = t4 * r2;
  const t8 = t4 * t4;
  const radial = i.k1 * r2 + i.k2 * t4 + i.k3 * t6 + i.k4 * t8;
  // Tangential + thin-prism terms vanish exactly when p1=p2=sx1=sy1=0.
  const dx = uu.x * radial + 2 * i.p1 * uu.x * uu.y + i.p2 * (r2 + 2 * uu.x * uu.x) + i.sx1 * r2;
  const dy = uu.y * radial + i.p1 * (r2 + 2 * uu.y * uu.y) + 2 * i.p2 * uu.x * uu.y + i.sy1 * r2;
  return { x: uu.x + dx, y: uu.y + dy };
}

/** 2D Newton to solve `_fisheyeApplyDistortion(uu) = p` for `uu` (numeric Jacobian). */
function _fisheyeRemoveDistortion2D(p: Vec2, i: CameraIntrinsics): Vec2 {