Is there a library for vehicle plate recognition written to work with xamarin forms.
There isn't one readily available. These things tend to be the domain of high-end security libraries.
You could potentially use an open source project like https://github.com/openalpr/openalpr and then use bindings to bring it in to the various platforms. It would mean you would need to understand the binding mechanisms. You would have to do bindings yourself, but there are resources that can help you.
Chris Van Wyk has an excellent lightning lecture on iOS bindings available at https://university.xamarin.com/lightninglectures
There are also guides available for iOS and Android available from https://developer.xamarin.com/guides/ios/advanced_topics/native_interop/ and https://developer.xamarin.com/guides/android/advanced_topics/using_native_libraries/
Once you have the platform specific instance you could then write a mechanism using the DependancyService to be able to call into the imported native libraries via Xamarin.Forms.
I hope that helps.
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