How to Distinguish Slashed Zero From Eight (0-8) in OCR

Question

I'm using ML Kit for Firebase for my Android app (ReCalc: Receipt Calculator) and it performs very well except in the case of slashed zero. In around half or more of the cases it recognizes slashed zero as eight.

One idea I have is to slice the rectangle containing the zero in regions and detect whether the regions just above and below the middle are dark or not. But actually...

I'm planning to train a model to classify zeroes and eights.

This is a lot of work thus I decided first to ask here for another solution/idea.

Here is an example:

Example of incorrectly recognized zeroes and eights

Similar question: Tesseract OCR confuses slashed 0 as 8

user_11886026 · Answer

Finally I've trained a model myself.

Its accuracy is pretty good (more than 98%). However I have concerns how well it generalize.

Here is the project: ZEC - Slashed Zero-Eight Classifier

I've created also an application showing how to use the model on Android: ZECA - Slashed Zero-Eight Classifier for Android

How to Distinguish Slashed Zero From Eight (0->8) in OCR

1 Answers