In addition to social media applications and games, it will not hurt to have useful programs on your smartphone. Now QR codes are found almost everywhere: on city streets, food packaging and business cards. Of course, to read them, you need special software. The five best solutions for this task will be discussed below.
QR Droid is distinguished, first of all, by a pleasant and, importantly, understandable interface. The application has long been known among users of Android devices. After launching, you can immediately scan the required code. If it contained a link to a web page, then it will automatically go to the built-in browser. However, this can be disabled in the settings, or you can set your own option as the default browser. It is also interesting that right from the program you can create your own QR-code with the necessary information.
2. QR Code Reader
If you don't want to complicate your life and are looking for a simple scanner, then QR Code Reader is a great solution. There is only a camera (you can also choose a ready-made image from the gallery), a history of scanned QR codes and a flash button, nothing else.
3. BIDI
The BIDI app is a lot like QR Droid. Here we have great opportunities not only for the usual recognition of QR codes, but for creating our own. For example, business cards. Very comfortably. There are special separators for phone number, address, email, etc. You can then make the necessary edits in any field.
4. Neo Reader
Neo Reader is perhaps one of the most powerful solutions, as it allows you to read information not only from QR codes, but also from bar codes. Just like in a store: if the app fails to recognize the code, you can manually enter the numbers below it. There is also the ability to turn the sound on or off, as well as snapping to a location. The only strange thing is that the creation of your own QR codes is not provided directly in the program. Alternatively, a quick link to the relevant site is offered.
5. QR Reader
The first thing that grabs attention after launch is the moving red line. We are not sure if they fulfill any role (rather, it is just a decorative element), but it looks interesting. One more thing: the application, judging by the arrangement of the system buttons, works in horizontal mode, keep this in mind (although in the reading mode all content is arranged vertically). The menu has a history of scans and bookmarks. You can create your own QR codes.
Which QR code reader do you use?
Based on materials from AndroidPit
Scanning QR codes on Android smartphones is easier than taking a photo. All you need is:
- Smartphone or tablet with a camera;
- Internet.
I will explain everything as simply as possible and give you a hands-on session. Right here without departing from the article. Barcodes can be scanned using the same instructions.
“My smartphone's interface may differ from yours due to different theme and Android version. The differences do not affect the installation and use of the QR code scanner ”
First you need a QR code scanner. I found the easiest one. It has fewer annoying ads and scans just what you need. Installing it is very simple. It's even easier to use.
- First, go to the Google Play Market. And we write in the underlined red line: “qr code scanner”, or better “smart qr scanner and generator”. Click on the search icon or just the drop-down offer that suits us.
In addition, you can download another excellent scanning application from us -
How to scan a code from a saved picture?
You can also recognize a QR code from a picture on the Internet using special websites. I chose qrrd.ru, because it is the only site that loaded for me in less than 10 seconds and had a more or less pleasant interface.
How to use it? First, go to the site: qrrd.ru or directly to qrrd.ru/read. We see the following: 
The site menu is circled in green, which indicates everything he can do to help you. In our case, select “Recognize QR code”.
The next page opens with a big "+ Select Files" button. Click on it. After that, at the bottom there are options for how to “select files”. Here you can either take a photo and send it right away. Or click on the documents and select a photo that is already on your phone. I took the last path. 
Here I selected the tab with pictures, clicked on the folder where the pictures are stored on my phone and clicked on the image with the QR code, the same one that was already here in the article. 
Then it's up to the site. He automatically uploads himself a photo or picture, and then immediately recognizes and shows the result. 
Ready!.
Why would I even scan QR codes?
They may contain useful information. The likelihood of this is low, but it may be there. In addition, QR codes are often used in museums in order not to put up huge signs with a bunch of information, but simply use a small QR code and give everyone the opportunity to step aside and read about an exhibit on their phone. Everything is simple and convenient. That's why Denso Wave invented them.
QR code is a great stock tool. For example, it may contain an encrypted code that must be shown to the seller in order to receive a discount. There are a huge number of applications. Use it!
I have created an application that can scan a QR code. It works well with all android devices except Samsung Galaxy s4.
App does not scan QR code when using Galaxy s4.
Now that this Galaxy s4 has Android 4.2.2 version, I also tested my app on other devices that have the same Android version (4.2.2) as Nexus-4 and everything works great with it.
Is there any other hardware used to scan QR code in Galaxy s4?
Need help solving this weird problem!
Below is the code that I used in my application.
CameraManager.java
/ ** * This object wraps the Camera service object and expects to be the only one talking to it. The * implementation encapsulates the steps needed to take preview-sized images, which are used for * both preview and decoding. * * @author [email protected] (Daniel Switkin) * / public final class CameraManager (private static final String TAG = CameraManager.class.getSimpleName (); private static final int MIN_FRAME_WIDTH = 240; private static final int MIN_FRAME_HEIGHT = 240; private static final int MAX_FRAME_WIDTH = 480; private static final int MAX_FRAME_HEIGHT = 360; private static CameraManager cameraManager; static final int SDK_INT; // Later we can use Build.VERSION.SDK_INT static (int sdkInt; try (sdkInt = Integer.parseInt (Build.VERSION.SDK);) catch (NumberFormatException nfe) (// Just to be safe sdkInt = 10000;) SDK_INT = sdkInt;) private final Context context; private final CameraConfigurationManager configManager; private Camera camera; private Rect framingRect; private Rect framingRectInPreview; private boolean initialized; private boolean previewing ; private boolean reverseImage; private final boolean useOneShotPreviewCallback; / ** * Preview frames are delivered here, which we pass on to the registered handler. Make sure to * clear the handler so it will only receive one message. * / private final PreviewCallback previewCallback; / ** Autofocus callbacks arrive here, and are dispatched to the Handler which requested them. * / private final AutoFocusCallback autoFocusCallback; / ** * Initializes this static object with the Context of the calling Activity. * * @param context The Activity which wants to use the camera. * / public static void init (Context context) (if (cameraManager == null) (cameraManager = new CameraManager (context);)) / ** * Gets the CameraManager singleton instance. * * @return A reference to the CameraManager singleton. * / public static CameraManager get () (return cameraManager;) private CameraManager (Context context) (this.context = context; this.configManager = new CameraConfigurationManager (context); // Camera.setOneShotPreviewCallback () has a race condition in Cupcake, so we use the older // Camera.setPreviewCallback () on 1.5 and earlier. For Donut and later, we need to use // the more efficient one shot callback, as the older one can swamp the system and cause it // to run out of memory. We can "t use SDK_INT because it was introduced in the Donut SDK. useOneShotPreviewCallback = Integer.parseInt (Build.VERSION.SDK)> 3; // 3 = Cupcake previewCallback = new PreviewCallback (configManager, useOneShotPreviewCallback); autoFneShotPreviewCallback) = new AutoFocusCallback ();) / ** * Opens the camera driver and initializes the hardware parameters. * * @param holder The surface object which the camera will draw preview frames into. * @throws IOException Indicates the camera driver failed to open. * / public void openDriver (SurfaceHolder holder) throws IOException (if (camera == null) (camera = Camera.open (); if (camera == null) (throw new IOException ();)) camera.setPreviewDisplay (holder) ; if (! initialized) (initialized = true; configManager.initFromCameraParameters (camera);) configManager.setDesiredCameraParameters (camera); SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences (context); reverseImage = prefs.getEFERSEERSKEY; (prefs.getBoolean (PreferencesActivity.KEY_FRONT_LIGHT, false)) (FlashlightManager.enableFlashlight ();)) / ** * Closes the camera driver if still in use. * / public void closeDriver () (if (camera! = null) (FlashlightManager.disableFlashlight (); camera.release (); camera = null; // Make sure to clear these each time we close the camera, so that any scanning rect // requested by intent is forgotten.framingRect = null; framingRectInPreview = null;)) / ** * Asks the camera hardware to begin drawing preview frames to the screen. * / public void startPreview () (if (camera! = null &&! previewing) (camera.startPreview (); previewing = true;)) / ** * Tells the camera to stop drawing preview frames. * / public void stopPreview () (if (camera! = null && previewing) (if (! useOneShotPreviewCallback) (camera.setPreviewCallback (null);) camera.stopPreview (); previewCallback.setHandler (null, 0); autoFocusCallback.setHandler (null, 0); previewing = false;)) / ** * A single preview frame will be returned to the handler supplied. The data will arrive as byte * in the message.obj field, with width and height encoded as message.arg1 and message.arg2, * respectively. * * @param handler The handler to send the message to. * @param message The what field of the message to be sent. * / public void requestPreviewFrame (Handler handler, int message) (if (camera! = null && previewing) (previewCallback.setHandler (handler, message); if (useOneShotPreviewCallback) (camera.setOneShotPreviewCallback (previewCallback);) else (camera.setPreviewCallback (previewCallback);))) / ** * Asks the camera hardware to perform an autofocus. * * @param handler The Handler to notify when the autofocus completes. * @param message The message to deliver. * / public void requestAutoFocus (Handler handler, int message) (if (camera! = null && previewing) (autoFocusCallback.setHandler (handler, message); //Log.d(TAG, "Requesting auto-focus callback"); camera .autoFocus (autoFocusCallback);)) / ** * Calculates the framing rect which the UI should draw to show the user where to place the * barcode. This target helps with alignment as well as forces the user to hold the device * far enough away to ensure the image will be in focus. * * @return The rectangle to draw on screen in window coordinates. * / public Rect getFramingRect () (if (framingRect == null) (if (camera == null) (return null;) Point screenResolution = configManager.getScreenResolution (); int width = screenResolution.x * 3/4; if ( width< MIN_FRAME_WIDTH) { width = MIN_FRAME_WIDTH; } else if (width >MAX_FRAME_WIDTH) (width = MAX_FRAME_WIDTH;) int height = screenResolution.y * 3/4; if (height< MIN_FRAME_HEIGHT) { height = MIN_FRAME_HEIGHT; } else if (height > MAX_FRAME_HEIGHT) (height = MAX_FRAME_HEIGHT;) int leftOffset = (screenResolution.x - width) / 2; int topOffset = (screenResolution.y - height) / 2; framingRect = new Rect (leftOffset, topOffset, leftOffset + width, topOffset + height); Log.d (TAG, "Calculated framing rect:" + framingRect); ) return framingRect; ) / ** * Like (@link #getFramingRect) but coordinates are in terms of the preview frame, * not UI / screen. * / public Rect getFramingRectInPreview () (if (framingRectInPreview == null) (Rect rect = new Rect (getFramingRect ()); Point cameraResolution = configManager.getCameraResolution (); Point screenResolution = configManager.getScreenResolution (); / * updated for portrait instead of landscape rect.left = rect.left * cameraResolution.y / screenResolution.x; rect.right = rect.right * cameraResolution.y / screenResolution.x; rect.top = rect.top * cameraResolution.x / screenResolution .y; rect.bottom = rect.bottom * cameraResolution.x / screenResolution.y; * / rect.left = rect.left * cameraResolution.x / screenResolution.x; rect.right = rect.right * cameraResolution.x / screenResolution .x; rect.top = rect.top * cameraResolution.y / screenResolution.y; rect.bottom = rect.bottom * cameraResolution.y / screenResolution.y; framingRectInPreview = rect;) return framingRectInPreview;) / ** * Allows third party apps to specify the scanning rectangle dimensions, rather than de termine * them automatically based on screen resolution. * * @param width The width in pixels to scan. * @param height The height in pixels to scan. * / public void setManualFramingRect (int width, int height) (Point screenResolution = configManager.getScreenResolution (); if (width> screenResolution.x) (width = screenResolution.x;) if (height> screenResolution.y) (height = screenResolution .y;) int leftOffset = (screenResolution.x - width) / 2; int topOffset = (screenResolution.y - height) / 2; framingRect = new Rect (leftOffset, topOffset, leftOffset + width, topOffset + height); Log. d (TAG, "Calculated manual framing rect:" + framingRect); framingRectInPreview = null;) / ** * A factory method to build the appropriate LuminanceSource object based on the format * of the preview buffers, as described by Camera.Parameters. * * @param data A preview frame. * @param width The width of the image. * @param height The height of the image. * @return A PlanarYUVLuminanceSource instance. * / public PlanarYUVLuminanceSource buildLuminanceSource (byte data, int width, int height) (Rect rect = getFramingRectInPreview (); int previewFormat = configManager.getPreviewFormat (); String previewFormatString = configManager.getPreviewFormatStringat (); switch (This previewFormatString (); switch (This previewFormatStringat ()); switch the standard Android format which all devices are REQUIRED to support. // In theory, it the only one we should ever care about. case PixelFormat.YCbCr_420_SP: // This format has never been seen in the wild, but is compatible as we only care // about the Y channel, so allow it. case PixelFormat.YCbCr_422_SP: return new PlanarYUVLuminanceSource (data, width, height, rect.left, rect.top, rect.width (), rect.height (), reverseImage); default: // The Samsung Moment incorrectly uses this variant instead of the "sp" version. // Fortunately, it too has all the Y data up front, so we can read it. if ("yuv420p" .equals (previewFormatString)) (return new PlanarYUVLuminanceSource (data, width, height, rect.left, rect.top, rect.width (), rect.height (), reverseImage);)) throw new IllegalArgumentException ("Unsupported picture format:" + previewFormat + "/" + previewFormatString); ))
PreviewCallback.java
Final class PreviewCallback implements Camera.PreviewCallback (private static final String TAG = PreviewCallback.class.getSimpleName (); private final CameraConfigurationManager configManager; private final boolean useOneShotPreviewCallback; private Handler previewHandler; private int previewMessage; PreviewCallbackCallback .configManager = configManager; this.useOneShotPreviewCallback = useOneShotPreviewCallback;) void setHandler (Handler previewHandler, int previewMessage) (this.previewHandler = previewHandler; this.previewMessage = camera previewMessage;) public void (bytereviewFrame) .getCameraResolution (); if (! useOneShotPreviewCallback) (camera.setPreviewCallback (null);) if (previewHandler! = null) (Message message = previewHandler.obtainMessage (previewMessage, cameraResolution.x, cameraResolution.y, data); message.sendToTar get (); previewHandler = null; ) else (Log.d (TAG, "Got preview callback, but no handler for it");)))
QR code is a special matrix code developed back in 1994, which gained wide popularity only a few years ago. A wide variety of information can be hidden under a QR code: a link to a website, an image, an electronic business card, etc. Today we will take a look at what methods exist for recognizing QR codes on the iPhone.
You can scan a QR code on the iPhone in two ways: by regular means and using special applications.
Method 1: Camera app
IOS 11 introduces one very interesting feature: the Camera app can now automatically search and recognize QR codes. You just need to make sure that the appropriate setting is enabled in the smartphone settings.
Method 2: QRScanner
Third-party scanning applications that are distributed in the App Store provide more options than stock iPhone tools. Moreover, if you are the owner of an outdated model of an apple smartphone, then you probably do not have the opportunity to upgrade to the eleventh version. This means that such applications are the only way to give your phone a scanning function.
Method 3: Kaspersky QR Scanner
Not all links hidden under QR codes are safe. Some of them lead to malicious and phishing sites that can seriously harm your device and your privacy. And in order to protect yourself from a possible threat, it is recommended to use the Kaspersky QR Scanner application, which is not only a scanner, but also a protective tool against malicious websites.
