Remove the old legacy OCR code (#181)

* Remove the old legacy OCR code

* make OCR model a member variable

CardScan/Classes/CreditCardOcr/SSDCreditCardOcr.swift

@@ -7,14 +7,20 @@
 import UIKit
 
 @available(iOS 11.2, *)
-class SSDCreditCardOcr: CreditCardOcrImplementation {
-    override func recognizeCard(in fullImage: CGImage, roiRectangle: CGRect) -> CreditCardOcrPrediction {
+public class SSDCreditCardOcr: CreditCardOcrImplementation {
+    let ocr: OcrDD
+
+    public override init(dispatchQueue: DispatchQueue) {
+        ocr = OcrDD()
+        super.init(dispatchQueue: dispatchQueue)
+    }
+
+    public override func recognizeCard(in fullImage: CGImage, roiRectangle: CGRect) -> CreditCardOcrPrediction {
         guard let image = croppedImageForSsd(fullCardImage: fullImage, roiRectangle: roiRectangle)
             else {
                 return CreditCardOcrPrediction.emptyPrediction(cgImage: fullImage)
         }
 
-        let ocr = OcrDD()
         let startTime = Date()
         let number = ocr.perform(croppedCardImage: image)
         let duration = -startTime.timeIntervalSinceNow

CardScan/Classes/Expiry.swift

@@ -21,50 +21,4 @@ public struct Expiry: Hashable {
         let twoDigitYear = self.year % 100
         return String(format: "%02d/%02d", self.month, twoDigitYear)
     }
-
-    @available(iOS 11.2, *)
-    static func from(image: CGImage, within rect: CGRect) -> Expiry? {
-        guard let digits = RecognizedDigits.from(image: image, within: rect, minConfidence: 0.65) else {
-            return nil
-        }
-
-        let (string, _) = digits.toString()
-
-        if string.count != 4 {
-            return nil
-        }
-
-        let monthString = String(string.prefix(2))
-        let yearString = String(string.suffix(2))
-
-        if monthString.count != 2 && yearString.count != 2 {
-            return nil
-        }
-
-        guard let month = UInt(monthString) else {
-            return nil
-        }
-
-        if month <= 0 || month > 12 {
-            return nil
-        }
-
-        guard let year = UInt(yearString) else {
-            return nil
-        }
-
-        let now = Date()
-        let currentYear = Calendar.current.component(.year, from: now)
-        let currentMonth = Calendar.current.component(.month, from: now)
-        let fullYear = 2000 + year
-        if fullYear < currentYear || fullYear >= (currentYear + 10) {
-            return nil
-        }
-
-        if fullYear == currentYear && month < currentMonth {
-            return nil
-        }
-
-        return Expiry(string: string, month: month, year: fullYear)
-    }
 }