Detecting text orientation

Question

I am able to draw rectangles around text with the CIDetector (Using CIDetectorTypeText), but I can't find a way to detect text orientation. Does anyone know how to detect text orientation with Swift?

Answer 1

This will print out the recognized text orientations.

guard let image = CIImage(image: imageView.image!) else { return }

let detector = CIDetector(ofType: CIDetectorTypeText, context: nil, options: [
    CIDetectorAccuracy: CIDetectorAccuracyHigh
])

let orientations = [Int](1..<9).flatMap {
    detector?.features(in: image, options: [
        CIDetectorImageOrientation: $0
    ]).count ?? 0 > 0 ? $0 : nil
}

if orientations.filter({ $0 < 5 }).count == 4 {
    print("text has horizontal orientation")
} else if orientations.filter({ $0 > 4 }).count == 4 {
    print("text has vertical orientation")
} else {
    print("text has mixed orientation")
}