Are there any nodes which ouput a SINGLE value?

For example, I’d like to feed an image into a node, and get the value of the brightest pixel.
Or perhaps get the sum of all the pixels.
Or the average of all of the input pixels.
Or the difference between the largest pixel and the smallest pixel.

I’m really into making abstract animations, and this would help me control a number of things in an automated way.

I don’t seem to see anything “native” to the compositor that can do this - is anyone aware of any add-ons or scripts that are designed to achieve this within the compositor?

Thanks,
Sam

Have you seen this thread? #9