thanks so much for your time in advance. i tried the following code to grab digits from the attached image but the results were so bad. I would really appreciate some suggestions on how to preprocess the image so i can get better results. does the red background in the img makes it difficult to get result?

Issues:
There is an issue with the minus sign, when the sign touches the digit.
Example:

(In that case the minus sign is not identified).

Suggested solution:
Check if the background color is red or green, and if it's red, add a minus sign (if not exist).