Is there any existing software which can read the data from LCD screen via camera and put it to CSV or any other machine readable format?

Question

For example, I have cheap 1 euro Chinese thermometer like this

and I want to make a graph of the temperature depends on the time of the day. This cheap device does not have any integration with PC/Phone, no USB input/output, no Bluetooth, nothing. It has just battery and a digital screen.

Ideally, I would like to point the web camera to this device and get the data as CSV or text format table with 2 columns (datetime and temperature) with predefined time intervals like every 10 seconds. Is there any software/website which can do this via OCR or Artificial Intelligence/Machine Learning? I tried to use some web-based OCR and it does not work well for this kind of device and also it can do OCR of 1 image, not the interval OCRing.

Of course, I can buy the device which can give me a nice graph, data in any format via Bluetooth/wifi/USB Cable, etc., but it will cost like 50$ and I do not want to spend this money :) Yes, I want to spend 1$ and get the same results as for 50 :) Webcam and PC I already have.

Another reason, that I want to have a generic solution, which will work with most of the devices, that I do not need to buy 50$ device every time I want to measure something. Today I need a temperature, tomorrow I will need humidity, after tomorrow maybe voltage in 230 V socket and see if it changing over the day to complain to the electricity provider, etc.

Answer 1

You can use a combination of OpenCV (to get the image and perform initial processing of it to do things like text localisation) and possibly OCR (e.g. Tesseract) to convert the text to any format that you desire. I would recommend using python as the glue to stick all of these together and to output to CSV (it has a library for that of course).

There are even tutorials available online for how to do exactly this sort of thing, e.g.:

• Recognizing digits with OpenCV and python walks you though reading an electricity meter from a fixed angle.
• OpenCV OCR and text recognition with Tesseract walks you through spotting and processing text within images.

All of the above software is:

• Free, Gratis & Open Source
• Available for most platforms