Apple Vision framework – Text extraction from image

Question

I am using Vision framework for iOS 11 to detect text on image.

The texts are getting detected successfully, but how we can get the detected text?

Answer 1

This will return a overlay image with rectangle box on detected text

Here is the full xcode project https://github.com/cyruslok/iOS11-Vision-Framework-Demo

Hope it is helpful

// Text Detect
func textDetect(dectect_image:UIImage, display_image_view:UIImageView)->UIImage{
    let handler:VNImageRequestHandler = VNImageRequestHandler.init(cgImage: (dectect_image.cgImage)!)
    var result_img:UIImage = UIImage.init();

    let request:VNDetectTextRectanglesRequest = VNDetectTextRectanglesRequest.init(completionHandler: { (request, error) in
        if( (error) != nil){
            print("Got Error In Run Text Dectect Request");

        }else{
            result_img = self.drawRectangleForTextDectect(image: dectect_image,results: request.results as! Array)
        }
    })
    request.reportCharacterBoxes = true
    do {
        try handler.perform([request])
        return result_img;
    } catch {
        return result_img;
    }
}

func drawRectangleForTextDectect(image: UIImage, results:Array) -> UIImage {
    let renderer = UIGraphicsImageRenderer(size: image.size)
    var t:CGAffineTransform = CGAffineTransform.identity;
    t = t.scaledBy( x: image.size.width, y: -image.size.height);
    t = t.translatedBy(x: 0, y: -1 );

    let img = renderer.image { ctx in
        for item in results {
            let TextObservation:VNTextObservation = item
            ctx.cgContext.setFillColor(UIColor.clear.cgColor)
            ctx.cgContext.setStrokeColor(UIColor.green.cgColor)
            ctx.cgContext.setLineWidth(1)
            ctx.cgContext.addRect(item.boundingBox.applying(t))
            ctx.cgContext.drawPath(using: .fillStroke)

            for item_2 in TextObservation.characterBoxes!{
                let RectangleObservation:VNRectangleObservation = item_2
                ctx.cgContext.setFillColor(UIColor.clear.cgColor)
                ctx.cgContext.setStrokeColor(UIColor.red.cgColor)
                ctx.cgContext.setLineWidth(1)
                ctx.cgContext.addRect(RectangleObservation.boundingBox.applying(t))
                ctx.cgContext.drawPath(using: .fillStroke)
            }
        }

    }
    return img
}