Find x coordinate trick

[jmac698]

I saw a trick somewhere with masktools, which used a liinear ramp as a mask with another video as a way of finding the x coordinate of a certain value pixel. I can't remember exactly how it works.
I want to return the x coordinate, in script, of the pixel with the brighest luma.
I plan to scan a correlation surface to find a match.

In the really big picture, I'm trying to find the relative scale in one direction between two similar videos. Mvtools only directly finds zoom, which is not going to work. You have to supply aspect to it. I can't think of a way to trick mvtools into doing it, either.

[Gavino]

I saw a trick somewhere with masktools, which used a liinear ramp as a mask with another video as a way of finding the x coordinate of a certain value pixel. I can't remember exactly how it works.
You're probably thinking of this thread.