Tried googling first but could not find any interesting hits relevant to what i am looking for.

The wild idea is to put a camera in front of an energy meter or watt meter display and read the accumulated total in the display, and process it down to digital information like an integer or a float that i can save. It might be enough to capture a still, crop the image and do some ocr-like operation.

[![Energy meter example](https://i.stack.imgur.com/Haqoe.jpg)](https://i.stack.imgur.com/Haqoe.jpg)

The advantage over monitoring pulses is that You would keep track of the actual meter total, not a forever running incremental. 

I'm looking for suggestions and ideas and if anyone have experience of solving similar problems. Pointers to software or libraries appreciated. I know there are posts about bar code reading, but that is not matching my needs.