PDF417.mobi SDK for iOS

PDF417.mobi SDK for iOS enables you to perform scans of various barcodes in your app. You can integrate the SDK into your app simply by following the instructions below and your app will be able to scan and process data from the following barcode standards:

• PDF417 barcode
• QR code
• Code 128
• Code 39
• EAN 13
• EAN 8
• UPC A
• UPC E
• ITF
• Data Matrix
• Aztec

Using PDF417.mobi in your app requires a valid license key. You can obtain a demo license key by registering to Microblink dashboard. After registering, you will be able to generate a license key for your app. The license key is bound to bundle identifier of your app, so please make sure you enter the correct bundle identifier when asked.

For more information on how to integrate PDF417.mobi SDK into your app read the instructions below. Make sure you read the latest Release notes for the most recent changes and improvements.

Table of contents

• Requirements
• Quick Start
• Advanced PDF417.mobi integration instructions
  • UI customizations of built-in MBOverlayViewControllers and MBOverlaySubviews
    • Built-in overlay view controllers and overlay subviews
  • Using MBBarcodeOverlayViewController
  • Custom overlay view controller
  • Direct processing API
• MBRecognizer and available recognizers
  • The MBRecognizer concept
  • MBRecognizerCollection concept
  • List of available recognizers
    • Frame Grabber Recognizer
    • Success Frame Grabber Recognizer
    • PDF417 recognizer
    • Barcode recognizer
• Troubleshooting
  • Integration problems
  • SDK problems
  • Frequently asked questions and known problems
• Additional info

Requirements

SDK package contains Microblink framework and one or more sample apps which demonstrate framework integration. The framework can be deployed in iOS 8.0 or later, iPhone 4S or newer and iPad 2 or newer.

SDK performs significantly better when the images obtained from the camera are focused. Because of that, the SDK can have lower performance on iPad 2 and iPod Touch 4th gen devices, which don't have camera with autofocus.

Quick Start

Getting started with PDF417.mobi SDK

This Quick Start guide will help you to set up the scanning as quickly as possible. All steps described in this guide are required for the integration.

This guide sets up basic PDF417 and QR code scanning functionality, and closely follows the pdf417-sample app. We highly recommend you try to run the sample app. The sample app should compile and run on your device, and in the iOS Simulator.

The source code of the sample app can be used as the reference during the integration.

1. Initial integration steps

Using CocoaPods

• CocoaPods is a dependency manager for Objective-C, which automates and simplifies the process of using 3rd-party libraries.

• If you wish to use version v1.4.0 or above, you need to install Git Large File Storage by running these commands:

brew install git-lfs
git lfs install

• Be sure to restart your console after installing Git LFS

• Project dependencies to be managed by CocoaPods are specified in a file called Podfile. Create this file in the same directory as your Xcode project (.xcodeproj) file.

• Copy and paste the following lines into the TextEdit window:

platform :ios, '9.0'
    pod 'PPpdf417', '~> 7.1.0'

• Install the dependencies in your project:

$ pod install

• From now on, be sure to always open the generated Xcode workspace (.xcworkspace) instead of the project file when building your project:

open <YourProjectName>.xcworkspace

Integration without CocoaPods

• Download Pdf417.mobi SDK to your filesystem, or clone this git repository. Do that by running:

git clone [email protected]:PDF417/pdf417-ios.git

• Copy MicroBlink.framework and MicroBlink.bundle to your project folder.

• In your Xcode project, open the Project navigator. Drag the MicroBlink.framework and MicroBlink.bundle files to your project, ideally in the Frameworks group, together with other frameworks you're using. When asked, choose "Create groups", instead of the "Create folder references" option.

• Since Microblink.framework is a dynamic framework, you also need to add it to embedded binaries section in General settings of your target.

• Include the additional frameworks and libraries into your project in the "Linked frameworks and libraries" section of your target settings.

  • libc++.tbd
  • libz.tbd
  • libiconv.tbd
  • AudioToolbox.framework
  • CoreMedia.framework
  • AssetsLibrary.framework

2. Referencing header file

In files in which you want to use scanning functionality place import directive.

Swift

import MicroBlink

Objective-C

#import <MicroBlink/MicroBlink.h>

3. Initiating the scanning process

1. Before starting a recognition process, you need to obtain a license from Microblink dashboard. After registering, you will be able to generate a trial license for your app. License is bound to Bundle ID of your app, so please make sure you enter the correct Bundle ID when asked.

   You must ensure that license key is set before instantiating any other classes from the SDK, otherwise you will get an exception at runtime.

   Swift

   /** First, set license key as soon as possible */
   MBMicroblinkSDK.sharedInstance().setLicenseResource("<license_name>", withExtension: "<extension>", inSubdirectory: "<subdirectory-name>", for: <bundle>)

   Objective-C

   /** First, set license key as soon as possible */
   [[MBMicroblinkSDK sharedInstance] setLicenseResource:@"<license_name>" withExtension:@"t<extension>" inSubdirectory:@"<subdirectory-name>" forBundle:<bundle>];

2. To initiate the scanning process, first decide where in your app you want to add scanning functionality. Usually, users of the scanning library have a button which, when tapped, starts the scanning process. Initialization code is then placed in touch handler for that button. Here we're listing the initialization code as it looks in a touch handler method. It is important to hold reference of recognizer which you want to use.

   Swift

   @IBAction func didTapScan(_ sender: AnyObject) {
   
       /** Create barcode recognizer */
       self.barcodeRecognizer = MBBarcodeRecognizer()
       self.barcodeRecognizer?.scanQrCode = true
       
       self.pdf417Recognizer = MBPdf417Recognizer()
       
       /** Create barcode settings */
       let settings : MBBarcodeOverlaySettings = MBBarcodeOverlaySettings()
       
       /** Crate recognizer collection */
       let recognizerList = [self.barcodeRecognizer!, self.pdf417Recognizer!]
       let recognizerCollection : MBRecognizerCollection = MBRecognizerCollection(recognizers: recognizerList)
       
       /** Create your overlay view controller */
       let barcodeOverlayViewController : MBBarcodeOverlayViewController = MBBarcodeOverlayViewController(settings: settings, recognizerCollection: recognizerCollection, delegate: self)
       
       /** Create recognizer view controller with wanted overlay view controller */
       let recognizerRunneViewController : UIViewController = MBViewControllerFactory.recognizerRunnerViewController(withOverlayViewController: barcodeOverlayViewController)
       
       /** Present the recognizer runner view controller. You can use other presentation methods as well (instead of presentViewController) */
       self.present(recognizerRunneViewController, animated: true, completion: nil)
   }

   Objective-C

   - (IBAction)didTapScan:(id)sender {
       
        /** Create recognizers */
       self.barcodeRecognizer = [[MBBarcodeRecognizer alloc] init];
       self.barcodeRecognizer.scanQR = YES;
   
       self.pdf417Recognizer = [[MBPdf417Recognizer alloc] init];
               
       MBBarcodeOverlaySettings* settings = [[MBBarcodeOverlaySettings alloc] init];
       
       NSMutableArray<MBRecognizer *> *recognizers = [[NSMutableArray alloc] init];
       [recognizers addObject:self.barcodeRecognizer];
       [recognizers addObject:self.pdf417Recognizer];
       
       /** Create recognizer collection */
       MBRecognizerCollection *recognizerCollection = [[MBRecognizerCollection alloc] initWithRecognizers:recognizers];
   
       MBBarcodeOverlayViewController *overlayVC = [[MBBarcodeOverlayViewController alloc] initWithSettings:settings recognizerCollection:recognizerCollection delegate:self];
       UIViewController<MBRecognizerRunnerViewController>* recognizerRunnerViewController = [MBViewControllerFactory recognizerRunnerViewControllerWithOverlayViewController:overlayVC];
   
       /** Present the recognizer runner view controller. You can use other presentation methods as well (instead of presentViewController) */
       [self presentViewController:recognizerRunnerViewController animated:YES completion:nil];
   }

3. In this example, we are using MBBarcodeOverlayViewController which has MBBarcodeOverlayViewControllerDelegate. It is necessary to conform to that protocol. We will discuss more about protocols in Advanced integration section. You can obtain the scanning results in one of the methods of MBBarcodeOverlayViewControllerDelegate protocol.

   Swift

   // MARK: MBBarcodeOverlayViewControllerDelegate
   extension ViewController : MBBarcodeOverlayViewControllerDelegate {
       
       func barcodeOverlayViewControllerDidFinishScanning(_ barcodeOverlayViewController: MBBarcodeOverlayViewController, state: MBRecognizerResultState) {
           
           let recognizerRunnerViewController = barcodeOverlayViewController.recognizerRunnerViewController as MBRecognizerRunnerViewController
           /** This callback is done on background thread and you need to be careful to not do any UI operations on it */
           recognizerRunnerViewController.pauseScanning()
           
           var message: String = ""
           var title: String = ""
           
           if (self.barcodeRecognizer!.result.resultState == MBRecognizerResultState.valid) {
               // Result handling
           }
           /** Needs to be called on main thread beacuse everything prior is on background thread */
           DispatchQueue.main.async {
               // UI actions
           }
       }
       
       func barcodeOverlayViewControllerDidTapClose(_ barcodeOverlayViewController: MBBarcodeOverlayViewController) {
           // Close button tapped on overlay view controller
       }
       
   }

   Objective-C

   #pragma mark - MBBarcodeOverlayViewControllerDelegate
   - (void)barcodeOverlayViewControllerDidFinishScanning:(MBBarcodeOverlayViewController *)barcodeOverlayViewController state:(MBRecognizerResultState)state {
       /** This callback is done on background thread and you need to be careful to not do any UI operations on it */
       [barcodeOverlayViewController.recognizerRunnerViewController pauseScanning];
       if (self.barcodeRecognizer.result.resultState == MBRecognizerResultStateValid) {
       }      
       /** Needs to be called on main thread beacuse everything prior is on background thread */
       dispatch_async(dispatch_get_main_queue(), ^{
           // UI actions
       });
   }
    - (void)barcodeOverlayViewControllerDidFinishScanning:(MBBarcodeOverlayViewController *)barcodeOverlayViewController {
       // Close button tapped on overlay view controller
   }

Advanced PDF417.mobi integration instructions

This section covers more advanced details of PDF417.mobi integration.

1. First part will cover the possible customizations when using UI provided by the SDK.
2. Second part will describe how to embed MBRecognizerRunnerViewController's delegates into your UIViewController with the goal of creating a custom UI for scanning, while still using camera management capabilites of the SDK.
3. Third part will describe how to use the MBRecognizerRunner (Direct API) for recognition directly from UIImage without the need of camera or to recognize camera frames that are obtained by custom camera management.
4. Fourth part will describe recognizer concept and available recognizers.

UI customizations of built-in MBOverlayViewControllers and MBOverlaySubviews

Built-in overlay view controllers and overlay subviews

Within PDF417.mobi SDK there are several built-in overlay view controllers and scanning subview overlays that you can use to perform scanning.

MBBarcodeOverlayViewController

MBBarcodeOverlayViewController is overlay view controller best suited for performing scanning of various barcodes. It has MBBarcodeOverlayViewControllerDelegate delegate which can be used out of the box to perform scanning using the default UI.

Using MBBarcodeOverlayViewController

MBBarcodeOverlayViewController is built-in overlay view controller which is best suiteed to use while scanning various barcodes. As you have seen in Quick Start, MBBarcodeOverlayViewController has MBBarcodeOverlaySettings. Here is an example how to use and initialize MBBarcodeOverlayViewController:

Swift

/** Create your overlay view controller */
let barcodeOverlayViewController : MBBarcodeOverlayViewController = MBBarcodeOverlayViewController(settings: barcodeSettings, andDelegate: self)

/** Create recognizer view controller with wanted overlay view controller */
let recognizerRunneViewController : UIViewController = MBViewControllerFactory.recognizerRunnerViewController(withOverlayViewController: barcodeOverlayViewController)

/** Present the recognizer runner view controller. You can use other presentation methods as well (instead of presentViewController) */
self.present(recognizerRunneViewController, animated: true, completion: nil)

Objective-C

MBBarcodeOverlayViewController *overlayVC = [[MBBarcodeOverlayViewController alloc] initWithSettings:settings andDelegate:self];
UIViewController<MBRecognizerRunnerViewController>* recognizerRunnerViewController = [MBViewControllerFactory recognizerRunnerViewControllerWithOverlayViewController:overlayVC];

/** Present the recognizer runner view controller. You can use other presentation methods as well (instead of presentViewController) */
[self presentViewController:recognizerRunnerViewController animated:YES completion:nil];

As you can see, when initializing MBBarcodeOverlayViewController, we are sending delegate property as self. To get results, we need to conform to MBBarcodeOverlayViewControllerDelegate protocol.

Custom overlay view controller

Overlay View Controller is an abstract class for all overlay views.

It's responsibility is to provide meaningful and useful interface for the user to interact with.

Typical actions which need to be allowed to the user are:

• intuitive and meaniningful way to guide the user through scanning process. This is usually done by presenting a "viewfinder" in which the user need to place the scanned object
• a way to cancel the scanning, typically with a "cancel" or "back" button
• a way to power on and off the light (i.e. "torch") button

PDF417.mobi SDK always provides it's own default implementation of the Overlay View Controller for every specific use. Your implementation should closely mimic the default implementation as it's the result of thorough testing with end users. Also, it closely matches the underlying scanning technology.

For example, the scanning technology usually gives results very fast after the user places the device's camera in the expected way above the scanned object. This means a progress bar for the scan is not particularly useful to the user. The majority of time the user spends on positioning the device's camera correctly. That's just an example which demonstrates careful decision making behind default camera overlay view.

1. Initialization

To use your custom overlay with MicroBlink's camera view, you must first subclass MBOverlayViewController and implement the overlay behaviour conforming wanted protocols.

2. Protocols

There are five MBRecognizerRunnerViewController protocols.

Five RecognizerRunnerView protocols are:

• MBScanningRecognizerRunnerViewDelegate
• MBDetectionRecognizerRunnerViewDelegate
• MBOcrRecognizerRunnerViewDelegate
• MBDebugRecognizerRunnerViewDelegate
• MBRecognizerRunnerViewControllerDelegate

MBCustomOverlayViewControllerMBCustomOverlayViewController class needs to be inherited by custom view controller and it needs to conform MBScanningRecognizerRunnerViewControllerDelegate. It contains all the properties needed for your custom view controller.

In viewDidLoad, scanningRecognizerRunnerViewControllerDelegate has to be set on super property:

Swift and Objective-C

super.scanningRecognizerRunnerViewControllerDelegate = self;

3. Overlay subviews

Developer needs to know which subivew is needed for custom view controller. If you want to use built-in implementation we recommend to use MBModernViewfinderOverlaySubview. In can be initialized in viewDidLoad method:

Swift

viewfinderSubview = MBModernViewfinderOverlaySubview()
viewfinderSubview.moveable = true
view.addSubview(viewfinderSubview)

Objective-C

self.viewfinderSubview = [[MBModernViewfinderOverlaySubview alloc] init];
self.viewfinderSubview.delegate = self.overlaySubviewsDelegate;
self.viewfinderSubview.moveable = YES;
[self.view addSubview:self.viewfinderSubview];

4. Initialization

In Quick Start guide it is shown how to use MBBarcodeOverlayViewController. You can now swap MBBarcodeOverlayViewController with CustomOverlayViewController

Swift

let recognizerRunnerViewController : UIViewController = MBViewControllerFactory.recognizerRunnerViewController(withOverlayViewController: CustomOverlayViewController)

Objective-C

UIViewController<MBRecognizerRunnerViewController>* recognizerRunnerViewController = [MBViewControllerFactory recognizerRunnerViewControllerWithOverlayViewController:CustomOverlayViewController];

Direct processing API

This guide will in short present you how to process UIImage objects with PDF417.mobi SDK, without starting the camera video capture.

With this feature you can solve various use cases like: - recognizing text on images in Camera roll - taking full resolution photo and sending it to processing - scanning barcodes on images in e-mail etc.

DirectAPI-sample demo app here will present UIImagePickerController for taking full resolution photos, and then process it with MicroBlink SDK to get scanning results using Direct processing API.

Direct processing API is handled with MBRecognizerRunner. That is a class that handles processing of images. It also has protocols as MBRecognizerRunnerViewController. Developer can choose which protocol to conform:

• MBScanningRecognizerRunnerDelegate
• MBDetectionRecognizerRunnerDelegate
• MBDebugRecognizerRunnerDelegate
• MBOcrRecognizerRunnerDelegate

In example, we are conforming to MBScanningRecognizerRunnerDelegate protocol.

To initiate the scanning process, first decide where in your app you want to add scanning functionality. Usually, users of the scanning library have a button which, when tapped, starts the scanning process. Initialization code is then placed in touch handler for that button. Here we're listing the initialization code as it looks in a touch handler method.

Swift

func setupRecognizerRunner() {
    var recognizers = [AnyHashable]() as? [MBRecognizer]
    pdf417Recognizer = MBPdf417Recognizer()
    recognizers.append(pdf417Recognizer)
    let settings = MBSettings()
    settings.uiSettings.recognizerCollection = MBRecognizerCollection(recognizers: recognizers)
    recognizerRunner = MBRecognizerRunner(settings: settings as? [String : Any] ?? [String : Any]())
    recognizerRunner.scanningRecognizerRunnerDelegate = self
}

func processImageRunner(_ originalImage: UIImage) {
    let image = MBImage(uiImage: originalImage)
    image.cameraFrame = true
    image.orientation = PPProcessingOrientationLeft
    let _serialQueue = DispatchQueue(label: "com.microblink.DirectAPI-sample")
    _serialQueue.async(execute: {() -> Void in
        self.recognizerRunner.processImage(image)
    })
}

func recognizerRunnerDidFinish(_ recognizerRunner: MBRecognizerRunner, state: MBRecognizerResultState) {
    if pdf417Recognizer.result.resultState == MBRecognizerResultStateValid {
        // Handle result
    }
}

Objective-C

- (void)setupRecognizerRunner {
    NSMutableArray<MBRecognizer *> *recognizers = [[NSMutableArray alloc] init];
    
    NSError *error;
    self.pdf417Recognizer = [[MBPdf417Recognizer alloc] init];
    
    [recognizers addObject:self.pdf417Recognizer];
    
    MBSettings* settings = [[MBSettings alloc] init];
    settings.uiSettings.recognizerCollection = [[MBRecognizerCollection alloc] initWithRecognizers:recognizers];
    
    self.recognizerRunner = [[MBRecognizerRunner alloc] initWithSettings:settings];
    self.recognizerRunner.scanningRecognizerRunnerDelegate = self;
}

- (void)processImageRunner:(UIImage *)originalImage {
    MBImage *image = [MBImage imageWithUIImage:originalImage];
    image.cameraFrame = YES;
    image.orientation = PPProcessingOrientationLeft;
    dispatch_queue_t _serialQueue = dispatch_queue_create("com.microblink.DirectAPI-sample", DISPATCH_QUEUE_SERIAL);
    dispatch_async(_serialQueue, ^{
        [self.recognizerRunner processImage:image];
    });
}

#pragma mark - MBScanningRecognizerRunnerDelegate
- (void)recognizerRunnerDidFinish:(MBRecognizerRunner *)recognizerRunner state:(MBRecognizerResultState)state {
    if (self.pdf417Recognizer.result.resultState == MBRecognizerResultStateValid) {
        // Handle result
    }
}

Now you've seen how to implement the Direct processing API.

In essence, this API consists of two steps:

• Initialization of the scanner.
• Call of processImage: method for each UIImage or CMSampleBufferRef you have.

MBRecognizer and available recognizers

The MBRecognizer concept

The MBRecognizer is the basic unit of processing within the SDK. Its main purpose is to process the image and extract meaningful information from it. As you will see later, the SDK has lots of different MBRecognizer objects that have various purposes.

Each MBRecognizer has a MBRecognizerResult object, which contains the data that was extracted from the image. The MBRecognizerResult object is a member of corresponding MBRecognizer object its lifetime is bound to the lifetime of its parent MBRecognizer object. If you need your MBRecognizerRecognizer object to outlive its parent MBRecognizer object, you must make a copy of it by calling its method copy.

While MBRecognizer object works, it changes its internal state and its result. The MBRecognizer object's MBRecognizerResult always starts in Empty state. When corresponding MBRecognizer object performs the recognition of given image, its MBRecognizerResult can either stay in Empty state (in case MBRecognizerfailed to perform recognition), move to Uncertain state (in case MBRecognizer performed the recognition, but not all mandatory information was extracted) or move to Valid state (in case MBRecognizer performed recognition and all mandatory information was successfully extracted from the image).

As soon as one MBRecognizer object's MBRecognizerResult within MBRecognizerCollection given to MBRecognizerRunner or MBRecognizerRunnerViewController changes to Valid state, the onScanningFinished callback will be invoked on same thread that performs the background processing and you will have the opportunity to inspect each of your MBRecognizer objects' MBRecognizerResult to see which one has moved to Valid state.

As soon as onScanningFinished method ends, the MBRecognizerRunnerViewController will continue processing new camera frames with same MBRecognizer objects, unless paused. Continuation of processing or reset recognition will modify or reset all MBRecognizer objects's MBRecognizerResult. When using built-in activities, as soon as onScanningFinished is invoked, built-in activity pauses the MBRecognizerRunnerViewController and starts finishing the activity, while saving the MBRecognizerCollection with active MBRecognizer.

MBRecognizerCollection concept

The MBRecognizerCollection is is wrapper around MBRecognizer objects that has array of MBRecognizer objects that can be used to give MBRecognizer objects to MBRecognizerRunner or MBRecognizerRunnerViewController for processing.

The MBRecognizerCollection is always constructed with array [[MBRecognizerCollection alloc] initWithRecognizers:recognizers] of MBRecognizer objects that need to be prepared for recognition (i.e. their properties must be tweaked already).

The MBRecognizerCollection manages a chain of MBRecognizer objects within the recognition process. When a new image arrives, it is processed by the first MBRecognizer in chain, then by the second and so on, iterating until a MBRecognizer object's MBRecognizerResult changes its state to Valid or all of the MBRecognizer objects in chain were invoked (none getting a Valid result state).

You cannot change the order of the MBRecognizer objects within the chain - no matter the order in which you give MBRecognizer objects to MBRecognizerCollection, they are internally ordered in a way that provides best possible performance and accuracy. Also, in order for SDK to be able to order MBRecognizer objects in recognition chain in a best way possible, it is not allowed to have multiple instances of MBRecognizer objects of the same type within the chain. Attempting to do so will crash your application.

List of available recognizers

This section will give a list of all MBRecognizer objects that are available within PDF417.mobi SDK, their purpose and recommendations how they should be used to get best performance and user experience.

Frame Grabber Recognizer

The MBFrameGrabberRecognizer is the simplest recognizer in SDK, as it does not perform any processing on the given image, instead it just returns that image back to its onFrameAvailable. Its result never changes state from empty.

This recognizer is best for easy capturing of camera frames with MBRecognizerRunnerViewController. Note that MBImage sent to onFrameAvailable are temporary and their internal buffers all valid only until the onFrameAvailable method is executing - as soon as method ends, all internal buffers of MBImage object are disposed. If you need to store MBImage object for later use, you must create a copy of it by calling copy.

Success Frame Grabber Recognizer

The MBSuccessFrameGrabberRecognizer is a special MBecognizer that wraps some other MBRecognizer and impersonates it while processing the image. However, when the MBRecognizer being impersonated changes its MBRecognizerResult into Valid state, the MBSuccessFrameGrabberRecognizer captures the image and saves it into its own MBSuccessFrameGrabberRecognizerResult object.

Since MBSuccessFrameGrabberRecognizer impersonates its slave MBRecognizer object, it is not possible to give both concrete MBRecognizer object and MBSuccessFrameGrabberRecognizer that wraps it to same MBRecognizerCollection - doing so will have the same result as if you have given two instances of same MBRecognizer type to the MBRecognizerCollection - it will crash your application.

This recognizer is best for use cases when you need to capture the exact image that was being processed by some other MBRecognizer object at the time its MBRecognizerResult became Valid. When that happens, MBSuccessFrameGrabberRecognizer's MBSuccessFrameGrabberRecognizerResult will also become Valid and will contain described image.

PDF417 recognizer

The MBPdf417Recognizer is recognizer specialised for scanning PDF417 2D barcodes. This recognizer can recognize only PDF417 2D barcodes - for recognition of other barcodes, please refer to BarcodeRecognizer.

This recognizer can be used in any overlay view controller, but it works best with the MBBarcodeOverlayViewController, which has UI best suited for barcode scanning.

Barcode recognizer

The MBBarcodeRecognizer is recognizer specialised for scanning various types of barcodes. This recognizer should be your first choice when scanning barcodes as it supports lots of barcode symbologies, including the PDF417 2D barcodes, thus making PDF417 recognizer possibly redundant, which was kept only for its simplicity.

You can enable multiple barcode symbologies within this recognizer, however keep in mind that enabling more barcode symbologies affect scanning performance - the more barcode symbologies are enabled, the slower the overall recognition performance. Also, keep in mind that some simple barcode symbologies that lack proper redundancy, such as Code 39, can be recognized within more complex barcodes, especially 2D barcodes, like PDF417.

This recognizer can be used in any overlay view controller, but it works best with the MBBarcodeOverlayViewController, which has UI best suited for barcode scanning.

Troubleshooting

Integration problems

In case of problems with integration of the SDK, first make sure that you have tried integrating it into XCode by following integration instructions.

If you have followed XCode integration instructions and are still having integration problems, please contact us at help.microblink.com.

SDK problems

In case of problems with using the SDK, you should do as follows:

Licencing problems

If you are getting "invalid licence key" error or having other licence-related problems (e.g. some feature is not enabled that should be or there is a watermark on top of camera), first check the console. All licence-related problems are logged to error log so it is easy to determine what went wrong.

When you have determine what is the licence-relate problem or you simply do not understand the log, you should contact us help.microblink.com. When contacting us, please make sure you provide following information:

• exact Bundle ID of your app (from your info.plist file)
• licence that is causing problems
• please stress out that you are reporting problem related to iOS version of PDF417.mobi SDK
• if unsure about the problem, you should also provide excerpt from console containing licence error

Other problems

If you are having problems with scanning certain items, undesired behaviour on specific device(s), crashes inside PDF417.mobi SDK or anything unmentioned, please do as follows:

• Contact us at help.microblink.com describing your problem and provide following information:
  • log file obtained in previous step
  • high resolution scan/photo of the item that you are trying to scan
  • information about device that you are using
  • please stress out that you are reporting problem related to iOS version of PDF417.mobi SDK

Frequently asked questions and known problems

Here is a list of frequently asked questions and solutions for them and also a list of known problems in the SDK and how to work around them.

In demo everything worked, but after switching to production license I get NSError with MBMicroblinkSDKRecognizerErrorDomain and MBRecognizerFailedToInitalize code as soon as I construct specific MBRecognizer object

Each license key contains information about which features are allowed to use and which are not. This NSError indicates that your production license does not allow using of specific MBRecognizer object. You should contact support to check if provided licence is OK and that it really contains all features that you have purchased.

I get NSError with MBMicroblinkSDKRecognizerErrorDomain and MBRecognizerFailedToInitalize code with trial license key

Whenever you construct any MBRecognizer object or, a check whether license allows using that object will be performed. If license is not set prior constructing that object, you will get NSError with MBMicroblinkSDKRecognizerErrorDomain and MBRecognizerFailedToInitalize code. We recommend setting license as early as possible in your app.

Undefined Symbols on Architecture armv7

Make sure you link your app with iconv and Accelerate frameworks as shown in Quick start. If you are using Cocoapods, please be sure that you've installed git-lfs prior to installing pods. If you are still getting this error, go to project folder and execute command git-lfs pull.

In my didFinish callback I have the result inside my MBRecognizer, but when scanning activity finishes, the result is gone

This usually happens when using MBRecognizerRunnerViewController and forgetting to pause the MBRecognizerRunnerViewController in your didFinish callback. Then, as soon as didFinish happens, the result is mutated or reset by additional processing that MBRecognizer performs in the time between end of your didFinish callback and actual finishing of the scanning activity. For more information about statefulness of the MBRecognizer objects, check this section.

Unsupported architectures when submitting app to App Store

Microblink.framework is a dynamic framework which contains slices for all architectures - device and simulator. If you intend to extract .ipa file for ad hoc distribution, you'll need to preprocess the framework to remove simulator architectures.

Ideal solution is to add a build phase after embed frameworks build phase, which strips unused slices from embedded frameworks.

Build step is based on the one provided here: http://ikennd.ac/blog/2015/02/stripping-unwanted-architectures-from-dynamic-libraries-in-xcode/

APP_PATH="${TARGET_BUILD_DIR}/${WRAPPER_NAME}"

# This script loops through the frameworks embedded in the application and
# removes unused architectures.
find "$APP_PATH" -name '*.framework' -type d | while read -r FRAMEWORK
do
FRAMEWORK_EXECUTABLE_NAME=$(defaults read "$FRAMEWORK/Info.plist" CFBundleExecutable)
FRAMEWORK_EXECUTABLE_PATH="$FRAMEWORK/$FRAMEWORK_EXECUTABLE_NAME"
echo "Executable is $FRAMEWORK_EXECUTABLE_PATH"

EXTRACTED_ARCHS=()

for ARCH in $ARCHS
do
echo "Extracting $ARCH from $FRAMEWORK_EXECUTABLE_NAME"
lipo -extract "$ARCH" "$FRAMEWORK_EXECUTABLE_PATH" -o "$FRAMEWORK_EXECUTABLE_PATH-$ARCH"
EXTRACTED_ARCHS+=("$FRAMEWORK_EXECUTABLE_PATH-$ARCH")
done

echo "Merging extracted architectures: ${ARCHS}"
lipo -o "$FRAMEWORK_EXECUTABLE_PATH-merged" -create "${EXTRACTED_ARCHS[@]}"
rm "${EXTRACTED_ARCHS[@]}"

echo "Replacing original executable with thinned version"
rm "$FRAMEWORK_EXECUTABLE_PATH"
mv "$FRAMEWORK_EXECUTABLE_PATH-merged" "$FRAMEWORK_EXECUTABLE_PATH"

done

Additional info

Complete API reference can be found here.

For any other questions, feel free to contact us at help.microblink.com.