二维码识别API

二维码识别API背景

二维码识别API技术在我们的日常生活中已经应用的非常广泛，如支付宝和微信中的扫一扫功能，应用的就是条码识别技术（二维码识别）。想必很多企业也想在自有的APP中集成这样的二维码识别API技术，针对这一需求，我们开发出二维码识别API，APP集成二维码识别API后，即可扫一扫识别各种条码（包含二维码、一维码）。



二维码识别API简介

二维码识别API是我们开发的一款基于android、ios平台的二维码识别API，目前支持对一维码、二维码的识别。开发包体积小，集成方便简单，可快速完成集成，集成后APP即可获取二维码识别API的功能。

二维码识别API特点：

1.快：识别速度快，单个条码识别速度小于0.1秒。

2.准：识别率高达99%

3.轻：开发包体积轻便，不到0.5M

4.全：识别条码全，可识别市面上所有的条码类型。

最近开发的项目中又涉及到二维码识别的技术，主要是做二维码扫码支付功能，我就从网上找了一个高逼格的可以自定义的三方库进行使用（使用的是博客一片枫叶_刘超，博客http://my.csdn.net/qq_23547831），首先看一下界面效果

首先你要引入三方库文件
compile 'cn.yipianfengye.android:zxing-library:2.2'

Java代码如下

             case R.id.button3://定制化二维码扫描模式
                intent = new Intent(MainActivity.this, SecondActivity.class);
                startActivityForResult(intent, REQUEST_CODE);
                break;

这里的SecondActivity就是自定义的Activity
只是比之前的CaptureActivity多了一行代码

        CodeUtils.setFragmentArgs(captureFragment, R.layout.my_camera);
这里的布局文件中引用了一个自定义的控件ViewFinerView，他是继承自View的


<declare-styleable name="ViewfinderView">
        <attr name="inner_width" format="dimension"/>
        <attr name="inner_height" format="dimension"/>
        <attr name="inner_margintop" format="dimension" />
        <attr name="inner_corner_color" format="color" />
        <attr name="inner_corner_length" format="dimension" />
        <attr name="inner_corner_width" format="dimension" />
        <attr name="inner_scan_bitmap" format="reference" />
        <attr name="inner_scan_speed" format="integer" />
        <attr name="inner_scan_iscircle" format="boolean" />
    </declare-styleable>



从上面的图片中你看到的所有矩形（包括上下左右的黑框和扫描的四个角的八个矩形）都是通过Canvas.drawRect(left,top,right,bottom)方法绘制的

/**
 * 自定义组件实现,扫描功能
 */
public final class ViewfinderView extends View {

    private static final long ANIMATION_DELAY = 100L;
    private static final int OPAQUE = 0xFF;

    private final Paint paint;
    private Bitmap resultBitmap;
    private final int maskColor;
    private final int resultColor;
    private final int resultPointColor;
    private Collection<ResultPoint> possibleResultPoints;
    private Collection<ResultPoint> lastPossibleResultPoints;
    // 扫描线移动的y
    private int scanLineTop;
    // 扫描线移动速度
    private int SCAN_VELOCITY;
    // 扫描线
    private Bitmap scanLight;
    // 是否展示小圆点
    private boolean isCircle;

    public ViewfinderView(Context context) {
        this(context, null);
    }

    public ViewfinderView(Context context, AttributeSet attrs) {
        this(context, attrs, -1);

    }

    public ViewfinderView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        paint = new Paint();
        Resources resources = getResources();
        maskColor = resources.getColor(R.color.viewfinder_mask);
        resultColor = resources.getColor(R.color.result_view);
        resultPointColor = resources.getColor(R.color.possible_result_points);
        possibleResultPoints = new HashSet<>(5);

        scanLight = BitmapFactory.decodeResource(resources,
                R.drawable.scan_light);

        initInnerRect(context, attrs);
    }

    /**
     * 初始化内部框的大小
     *
     * @param context
     * @param attrs
     */
    private void initInnerRect(Context context, AttributeSet attrs) {
        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ViewfinderView);
        // 扫描框距离顶部
        float innerMarginTop = ta.getDimension(R.styleable.ViewfinderView_inner_margintop, -1);
        if (innerMarginTop != -1) {
            CameraManager.FRAME_MARGINTOP = (int) innerMarginTop;
        }

        // 扫描框的宽度
        CameraManager.FRAME_WIDTH = (int) ta.getDimension(R.styleable.ViewfinderView_inner_width, DisplayUtil.screenWidthPx / 2);

        // 扫描框的高度
        CameraManager.FRAME_HEIGHT = (int) ta.getDimension(R.styleable.ViewfinderView_inner_height, DisplayUtil.screenWidthPx / 2);

        // 扫描框边角颜色
        innercornercolor = ta.getColor(R.styleable.ViewfinderView_inner_corner_color, Color.parseColor("#45DDDD"));
        // 扫描框边角长度
        innercornerlength = (int) ta.getDimension(R.styleable.ViewfinderView_inner_corner_length, 65);
        // 扫描框边角宽度
        innercornerwidth = (int) ta.getDimension(R.styleable.ViewfinderView_inner_corner_width, 15);

        // 扫描bitmap
        Drawable drawable = ta.getDrawable(R.styleable.ViewfinderView_inner_scan_bitmap);
        if (drawable != null) {

        }
        // 扫描控件
        scanLight = BitmapFactory.decodeResource(getResources(), ta.getResourceId(R.styleable.ViewfinderView_inner_scan_bitmap, R.drawable.scan_light));
        // 扫描速度
        SCAN_VELOCITY = ta.getInt(R.styleable.ViewfinderView_inner_scan_speed, 5);

        isCircle = ta.getBoolean(R.styleable.ViewfinderView_inner_scan_iscircle, true);

        ta.recycle();
    }

    @Override
    public void onDraw(Canvas canvas) {
        Rect frame = CameraManager.get().getFramingRect();
        if (frame == null) {
            return;
        }
        int width = canvas.getWidth();
        int height = canvas.getHeight();

        // Draw the exterior (i.e. outside the framing rect) darkened
        paint.setColor(resultBitmap != null ? resultColor : maskColor);
        canvas.drawRect(0, 0, width, frame.top, paint);
        canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, paint);
        canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1, paint);
        canvas.drawRect(0, frame.bottom + 1, width, height, paint);

        if (resultBitmap != null) {
            // Draw the opaque result bitmap over the scanning rectangle
            paint.setAlpha(OPAQUE);
            canvas.drawBitmap(resultBitmap, frame.left, frame.top, paint);
        } else {

            drawFrameBounds(canvas, frame);

            drawScanLight(canvas, frame);

            Collection<ResultPoint> currentPossible = possibleResultPoints;
            Collection<ResultPoint> currentLast = lastPossibleResultPoints;
            if (currentPossible.isEmpty()) {
                lastPossibleResultPoints = null;
            } else {
                possibleResultPoints = new HashSet<ResultPoint>(5);
                lastPossibleResultPoints = currentPossible;
                paint.setAlpha(OPAQUE);
                paint.setColor(resultPointColor);

                if (isCircle) {
                    for (ResultPoint point : currentPossible) {
                        canvas.drawCircle(frame.left + point.getX(), frame.top + point.getY(), 6.0f, paint);
                    }
                }
            }
            if (currentLast != null) {
                paint.setAlpha(OPAQUE / 2);
                paint.setColor(resultPointColor);

                if (isCircle) {
                    for (ResultPoint point : currentLast) {
                        canvas.drawCircle(frame.left + point.getX(), frame.top + point.getY(), 3.0f, paint);
                    }
                }
            }

            postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top, frame.right, frame.bottom);
        }
    }
    // 扫描框边角颜色
    private int innercornercolor;
    // 扫描框边角长度
    private int innercornerlength;
    // 扫描框边角宽度
    private int innercornerwidth;

    /**
     * 绘制取景框边框
     *
     * @param canvas
     * @param frame
     */
    private void drawFrameBounds(Canvas canvas, Rect frame) {

        /*paint.setColor(Color.WHITE);
        paint.setStrokeWidth(2);
        paint.setStyle(Paint.Style.STROKE);

        canvas.drawRect(frame, paint);*/

        paint.setColor(innercornercolor);
        paint.setStyle(Paint.Style.FILL);

        int corWidth = innercornerwidth;
        int corLength = innercornerlength;

        // 左上角
        canvas.drawRect(frame.left, frame.top, frame.left + corWidth, frame.top
                + corLength, paint);
        canvas.drawRect(frame.left, frame.top, frame.left
                + corLength, frame.top + corWidth, paint);
        // 右上角
        canvas.drawRect(frame.right - corWidth, frame.top, frame.right,
                frame.top + corLength, paint);
        canvas.drawRect(frame.right - corLength, frame.top,
                frame.right, frame.top + corWidth, paint);
        // 左下角
        canvas.drawRect(frame.left, frame.bottom - corLength,
                frame.left + corWidth, frame.bottom, paint);
        canvas.drawRect(frame.left, frame.bottom - corWidth, frame.left
                + corLength, frame.bottom, paint);
        // 右下角
        canvas.drawRect(frame.right - corWidth, frame.bottom - corLength,
                frame.right, frame.bottom, paint);
        canvas.drawRect(frame.right - corLength, frame.bottom - corWidth,
                frame.right, frame.bottom, paint);
    }


    /**
     * 绘制移动扫描线
     *
     * @param canvas
     * @param frame
     */
    private void drawScanLight(Canvas canvas, Rect frame) {

        if (scanLineTop == 0) {
            scanLineTop = frame.top;
        }

        if (scanLineTop >= frame.bottom - 30) {
            scanLineTop = frame.top;
        } else {
            scanLineTop += SCAN_VELOCITY;
        }
        Rect scanRect = new Rect(frame.left, scanLineTop, frame.right,
                scanLineTop + 30);
        canvas.drawBitmap(scanLight, null, scanRect, paint);
    }
    public void drawViewfinder() {
        resultBitmap = null;
        invalidate();
    }

    public void addPossibleResultPoint(ResultPoint point) {
        possibleResultPoints.add(point);
    }


    /**
     * 根据手机的分辨率从 dp 的单位 转成为 px(像素)
     */
    public static int dip2px(Context context, float dpValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }
}
用户可以根据自己的需求进行适当的修改颜色和文字等内容

最后附上github地址https://github.com/yipianfengye/android-zxingLibrary

Unity+Hololens二维码识别
文章下方附带zxing.unity.dll文件和Unity项目源码
进行二维码识别之前，需要对Hololens的开发环境进行配置，以及Unity开发Hololens需要的一些设置，介绍文章很多，不多说了。
开发环境

Unity 2018.4.14 （IL2CPP模式下）

Hololens 1代

VS 2019
识别二维码是基于zxing.unity.dll,需要放在Plugins文件夹下，并设置为所有平台通用


上代码
using UnityEngine;
using System.Collections;
using ZXing;
using UnityEngine.UI;
using System.Threading;
using System;

public class QRcode : MonoBehaviour
{
    /// <summary> 包含RGBA </summary>
    private Color32[] data;
    /// <summary> 相机捕捉到的图像 </summary>
    private WebCamTexture webCameraTexture;
    /// <summary> ZXing中的方法，可读取二维码中的内容 </summary>
    private BarcodeReader barcodeReader;
    /// <summary> 计时，0.5s扫描一次 </summary>
    private int timer = 500;

    public Text QRcodeText;
    public Animation scanAni;
    public AudioSource audio;
    public RawImage cameraTexture;

    Thread thread;

    public System.Collections.Concurrent.ConcurrentQueue<System.Action> _MainThreadQueue =
         new System.Collections.Concurrent.ConcurrentQueue<Action>();

    /// <summary>
    /// 初始化
    /// </summary>
    /// <returns></returns>
    IEnumerator Start()
    {
        barcodeReader = new BarcodeReader();
        yield return Application.RequestUserAuthorization(UserAuthorization.WebCam);//请求授权使用摄像头
        if (Application.HasUserAuthorization(UserAuthorization.WebCam))
        {
            WebCamDevice[] devices = WebCamTexture.devices;//获取摄像头设备
            string devicename = devices[0].name;
            webCameraTexture = new WebCamTexture(devicename, 400, 300);//获取摄像头捕捉到的画面

            cameraTexture.enabled = true;
            cameraTexture.texture = webCameraTexture;

            webCameraTexture.Play();
            scanAni.Play();

            thread = new Thread(ScanQRcode);
            thread.Start();
        }

    }

    void Update()
    {
        while (_MainThreadQueue.Count > 0)
        {
            if (_MainThreadQueue.TryDequeue(out Action func))
            {
                func?.Invoke();
            }
        }
    }

    private void OnDisable()
    {
        thread.Abort();
    }

    /// <summary>
    /// 子线程
    /// </summary>
    private void ScanQRcode()
    {
        while (true)
        {
            _MainThreadQueue.Enqueue(() =>
             {
                 data = webCameraTexture.GetPixels32();//相机捕捉到的纹理
                 DecodeQR(webCameraTexture.width, webCameraTexture.height);
             });
            Thread.Sleep(timer);
        }
    }

    /// <summary>
    /// 识别二维码并显示其中包含的文字、URL等信息
    /// </summary>
    /// <param name="width">相机捕捉到的纹理的宽度</param>
    /// <param name="height">相机捕捉到的纹理的高度</param>
    private void DecodeQR(int width, int height)
    {
        var br = barcodeReader.Decode(data, width, height);
        if (br != null)
        {
            QRcodeText.text = br.Text;
            audio.Play();
        }
        else
        {
            QRcodeText.text = "";
        }
    }
}

效果展示

(这是电脑上测试，Hololens 1代亲测OK)


文章参考
zxing.unity.dll    提取码：881g
Unity项目源码  提取码：ju0k

二维码识别

AVFoundation 二维码识别demo
主要代码：

 

#import "THCameraController.h"
#import <AVFoundation/AVFoundation.h>

@interface THCameraController ()<AVCaptureMetadataOutputObjectsDelegate>

@property(strong,nonatomic)AVCaptureMetadataOutput *metadataOutput; //通过代理方法，拿到接收元数据时的通知

@end


@implementation THCameraController

- (NSString *)sessionPreset {
    
    //重写sessionPreset方法，可以选择最适合应用程序捕捉预设类型。
    //苹果公司建议开发者使用最低合理解决方案以提高性能
    return AVCaptureSessionPreset640x480;
}

- (BOOL)setupSessionInputs:(NSError *__autoreleasing *)error {

    //设置相机自动对焦，这样可以在任何距离都可以进行扫描。
    BOOL success = [super setupSessionInputs:error];
    if(success)
    {
        //判断是否能自动聚焦
        if (self.activeCamera.autoFocusRangeRestrictionSupported) {
            
            //锁定设备
            if ([self.activeCamera lockForConfiguration:error]) {
                
                //自动聚焦
                /*
                    iOS 7.0新增属性 允许使用范围约束来对功能进行定制。
                  因为扫描条码，距离都比较近。所以AVCaptureAutoFocusRangeRestrictionNear，
                 通过缩小距离，来提高识别成功率。
                 */
                self.activeCamera.autoFocusRangeRestriction = AVCaptureAutoFocusRangeRestrictionNear;
                
                //释放排他锁
                [self.activeCamera  unlockForConfiguration];
            }
        }
    }

    return YES;
}

- (BOOL)setupSessionOutputs:(NSError **)error {

    //获取输出设备
    self.metadataOutput = [[AVCaptureMetadataOutput alloc]init];
    
    //判断是否能添加输出设备
    if ([self.captureSession canAddOutput:self.metadataOutput]) {
        
        //添加输出设备
        [self.captureSession addOutput:self.metadataOutput];
        
        dispatch_queue_t mainQueue = dispatch_get_main_queue();
        
        //设置委托代理
        [self.metadataOutput setMetadataObjectsDelegate:self queue:mainQueue];
        
        //指定扫描对是OR码 & Aztec 码 (移动营销)
        NSArray *types = @[AVMetadataObjectTypeQRCode,AVMetadataObjectTypeAztecCode,AVMetadataObjectTypeDataMatrixCode,AVMetadataObjectTypePDF417Code];
        
        self.metadataOutput.metadataObjectTypes = types;
        
    }else
    {
        //错误时，存储错误信息
        NSDictionary *userInfo = @{NSLocalizedDescriptionKey:@"Faild to add metadata output."};
        *error = [NSError errorWithDomain:THCameraErrorDomain code:THCameraErrorFailedToAddOutput userInfo:userInfo];
    
        return NO;
    }
    
    return YES;
    
}


//委托代理回掉。处理条码
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputMetadataObjects:(NSArray *)metadataObjects
       fromConnection:(AVCaptureConnection *)connection {
    
    if (metadataObjects.count > 0) {
        
        NSLog(@"%@",metadataObjects[0]);
        
        /*
         <AVMetadataMachineReadableCodeObject: 0x17002db20, type="org.iso.QRCode", bounds={ 0.4,0.4 0.1x0.2 }>corners { 0.4,0.6 0.6,0.6 0.6,0.4 0.4,0.4 }, time 122373330766250, stringValue ""http://www.echargenet.com/portal/csService/html/app.html
         */

    }
    
    //获取了
    [self.codeDetectionDelegate didDetectCodes:metadataObjects];

}

@end


人脸识别

AVFoundation 实现人脸识别demo
主要代码：

 

#import "THCameraController.h"
#import <AVFoundation/AVFoundation.h>

@interface THCameraController ()<AVCaptureMetadataOutputObjectsDelegate>
@property(nonatomic,strong)AVCaptureMetadataOutput  *metadataOutput;
@end

@implementation THCameraController

- (BOOL)setupSessionOutputs:(NSError **)error {
    
    self.metadataOutput = [[AVCaptureMetadataOutput alloc]init];
    
    //为捕捉会话添加设备
    if ([self.captureSession canAddOutput:self.metadataOutput]){
        [self.captureSession addOutput:self.metadataOutput];
        
        
        //获得人脸属性
        NSArray *metadatObjectTypes = @[AVMetadataObjectTypeFace];
        
        //设置metadataObjectTypes 指定对象输出的元数据类型。
        /*
         限制检查到元数据类型集合的做法是一种优化处理方法。可以减少我们实际感兴趣的对象数量
         支持多种元数据。这里只保留对人脸元数据感兴趣
         */
        self.metadataOutput.metadataObjectTypes = metadatObjectTypes;
        
        //创建主队列： 因为人脸检测用到了硬件加速，而且许多重要的任务都在主线程中执行，所以需要为这次参数指定主队列。
        dispatch_queue_t mainQueue = dispatch_get_main_queue();
        
        
        //通过设置AVCaptureVideoDataOutput的代理，就能获取捕获到一帧一帧数据
        [self.metadataOutput setMetadataObjectsDelegate:self queue:mainQueue];
     
        return YES;
    }else
    {
        //报错
        if (error) {
            NSDictionary *userInfo = @{NSLocalizedDescriptionKey:@"Failed to still image output"};
            
            *error = [NSError errorWithDomain:THCameraErrorDomain code:THCameraErrorFailedToAddOutput userInfo:userInfo];
            
        }
        return NO;
    }

}



//捕捉数据
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputMetadataObjects:(NSArray *)metadataObjects
       fromConnection:(AVCaptureConnection *)connection {

    
    //使用循环，打印人脸数据
    for (AVMetadataFaceObject *face in metadataObjects) {
        
        NSLog(@"Face detected with ID:%li",(long)face.faceID);
        NSLog(@"Face bounds:%@",NSStringFromCGRect(face.bounds));
        
    }
    
    
    //将元数据 传递给 THPreviewView.m   将元数据转换为layer
    [self.faceDetectionDelegate didDetectFaces:metadataObjects];
    
}

@end