Vision language detection

Question

I'm using Vision provided by Apple to convert some images into text. It's working well, but the problem I currently have is with Chinese characters.

I'm doing this currently:

let request = VNRecognizeTextRequest(completionHandler: recognizeTextHandler)
request.recognitionLevel = .accurate
request.recognitionLanguages = try! VNRecognizeTextRequest.supportedRecognitionLanguages(for: .accurate,
revision: request.revision)

And it looks like it supports a bunch of latin languages along with Chinese.

Vision seems to be able to detect languages such as German just fine automatically, but I have to specify Chinese at the front of the recognitionLanguages property for it to work with Chinese.

Is there any way to automatically detect the language of the image?

Chinese is kind of special, because it only works with `.accurate`. It also takes much longer. The system probably prioritizes the other languages first. — aheze, Jun 10 '21 at 03:56

score 0 · Accepted Answer · answered Jun 10 '21 at 16:41

I have to specify Chinese at the front of the recognitionLanguages property for it to work with Chinese

This is how it was designed. .accurate uses a ML-based recognizer, and because Chinese is really complex, it must come first. See WWDC21's Extract document data using Vision at 8:02.

This also means that there is no way to automatically detect the language of the image.

Vision language detection

1 Answers1