Patent-pending... again someone trying to rent-seek a high-school physics fair idea. Measuring light absorption with a camera is almost as old as the camera.

Using a known reflectance chart in-scene to recover spectral information is a standard calibration technique.

What "investment" is patent law protecting here?

What you're referring to is color calibration. This is spectroscopy. This is likley more of a chemistry paper than a engineering paper because the ink in the reference chart is doing some heavy lifting.