Arduino. How to take a photo of a monochrome display with numbers for later recognition?

Question

Arduino

The organization has a bunch of different sensors / meters that have one common feature - numerical two-color indicators. Every day (sometimes several times a day) the human-molecule walks and takes readings manually, it needs to be automated.
So far, the test working version is a bunch of arduino + camera + wifi shield + battery (should be offline).
There are two snags - the price is high and the recognition algorithm messes up (due to the quality of photos in the dark and other moments).
How can I solve the first (assumption) - use radio channels-transmitters + receivers instead of wifi (all meters are directly accessible), but I have never been strong in plateau-soldering "from scratch".
The second solution (according to the encoder) can be solved by getting a monochrome photo initially, and preferably without unnecessary "noise", i.e. ideally - a stupid rectangle with numbers. I know for sure that this is possible, because. there are IP-cameras where you can use the mouse (! via html-area) to select the "working" area of ​​the photo, whiten the rest and "turn on" the monochrome mode (cameras with IR).
I would like links to articles on the topic of the camera + board in monochrome mode, and on recognition too (maybe there are special libraries). And of course, as cheap as possible :)

Answer 1

In industrial automation, there are a lot of sensors, protocols and systems for remote monitoring and data collection, so it’s much easier, better and more accurate to deal with the types of sensors, their communication interfaces, or replace sensors with those with interfaces than to fence such a collective farm.

Answer 2

It's easier to connect to the interface of the scoreboard itself (yes, directly to the board) and take readings directly without any cameras.
In order to neutralize the effect of day / night change to improve image quality, I recommend organizing a powerful infrared illumination of the scoreboard. Take black and white cameras without a light filter and turn the sensitivity to the very minimum so that on a day without backlight the image is almost black. When the powerful backlight is turned on, a very clear image appears on the camera, which is now independent of day / night. And such lighting does not interfere with the work of staff.

Answer 3

I do not quite understand the meaning of using arduino here. If the cameras are IP - well, take all the pictures on 1 computer, you can already cut out the desired area in the picture and apply all sorts of filters (I think I won’t be much mistaken if I recommend paying attention to OpenCV). Something tells me that five duin with WiFiShield will cost the same money as a decent computer.

Answer 4

The simplest solution. Each sensor is connected to a control unit (with indicator). Develop a new control unit (with Ethernet connection). Replace old control units with new ones.