nightstalkerpoet said:

Excuse my ignorance (as always) but could you simply physically scan a laserdisc surface at a microscopic zoom rate, and use a pc to analyze the lans/pits and pull the information from it? That way you could pull a 100% pure video signal from it?

That would most certainly be possible, but very difficult. Consider that the LD itself might be subject to minor warping (many are) and you'd need one hell of a digital tilt servo to compensate for that while tracking.

Then consider that you'd have to contend with occlusion defects (dirt and other material between the plastic and the aluminum layer), possible laser rot (oxidation of the aluminum layer), ..., the list goes on.

Also, keep in mind that the signal stored on a laserdisc is composite and, to the best of my knowledge, there are no free-and-open-source 3D comb filters that are as good as the proprietary ones.

So, it's hard to say what a "100% pure video signal" is when talking about laserdiscs. The information isn't stored digitally and each pressing has its own characteristics.