object/image recognition software development

Building an app with object detection software. It will be used for electrical meter reading (in India). The app should have the capacity to scan a meter using camera and extract information from the readings displayed on the meter and generate an electric bill using those readings. The readings should also be simultaneously uploaded to a cloud. Every electric meter looks the same (in the zone we operate in) and the information required from the image of those images as well as the mathematical basis for calculating bill will also remain the same. Hence it is a fairly simple task without requirement for any complex ML models. It should be robust and secure from any tampering (e.g, capacity for manipulating the readings by the executive taking the pictures).