上一张效果图，渣画质，能看就好

 

功能说明：

人脸识别使用的是虹软的FreeSDK，包含人脸追踪，人脸检测，人脸识别，年龄、性别检测功能，其中本demo只使用了FT和FR（人脸追踪和人脸识别），封装了开启相机和人脸追踪、识别功能在FaceCameraHelper中。

实现逻辑：

打开相机，监听预览数据回调进行人脸追踪，且为每个检测到的人脸都分配一个trackID（上下帧位置变化不大的人脸框可认为是同一个人脸，具体实现的逻辑可见代码），同时，为了人脸搜索，为每个trackID都分配一个状态（识别中，识别失败，识别通过）、姓名，识别通过则在人脸框上显示姓名，否则只显示trackID（本demo没配服务端，只做了模拟操作）。流程说明见下图。

 

FaceCameraHelper包含的接口：

 

public interface FaceTrackListener {/*** 回传相机预览数据和人脸框位置** @param nv21 相机预览数据* @param ftFaceList 待处理的人脸列表* @param trackIdList 人脸追踪ID列表*/void onPreviewData(byte[] nv21, List
     
       ftFaceList, List
      
        trackIdList);/*** 当出现异常时执行** @param e 异常信息*/void onFail(Exception e);/*** 当相机打开时执行** @param camera 相机实例*/void onCameraOpened(Camera camera);/*** 根据自己的需要可以删除部分人脸，比如指定区域、留下最大人脸等** @param ftFaceList 人脸列表* @param trackIdList 人脸追踪ID列表*/void adjustFaceRectList(List
       
         ftFaceList, List
        
          trackIdList);/*** 请求人脸特征后的回调** @param frFace 人脸特征数据* @param requestId 请求码*/void onFaceFeatureInfoGet(@Nullable AFR_FSDKFace frFace, Integer requestId);}```FT人脸框绘制并回调数据：
        
       
      
     

　　

 

 

@Overridepublic void onPreviewFrame(byte[] nv21, Camera camera) {if (faceTrackListener != null) {ftFaceList.clear();int ftCode = ftEngine.AFT_FSDK_FaceFeatureDetect(nv21, previewSize.width, previewSize.height, AFT_FSDKEngine.CP_PAF_NV21, ftFaceList).getCode();if (ftCode != 0) {faceTrackListener.onFail(new Exception("ft failed,code is " + ftCode));}refreshTrackId(ftFaceList);faceTrackListener.adjustFaceRectList(ftFaceList, currentTrackIdList);if (surfaceViewRect != null) {Canvas canvas = surfaceViewRect.getHolder().lockCanvas();if (canvas == null) {faceTrackListener.onFail(new Exception("can not get canvas of surfaceViewRect"));return;}canvas.drawColor(0, PorterDuff.Mode.CLEAR);if (ftFaceList.size() > 0) {for (int i = 0; i < ftFaceList.size(); i++) {Rect adjustedRect = TrackUtil.adjustRect(new Rect(ftFaceList.get(i).getRect()), previewSize.width, previewSize.height, surfaceWidth, surfaceHeight, cameraOrientation, mCameraId);TrackUtil.drawFaceRect(canvas, adjustedRect, faceRectColor, faceRectThickness, currentTrackIdList.get(i), nameMap.get(currentTrackIdList.get(i)));}}surfaceViewRect.getHolder().unlockCanvasAndPost(canvas);}faceTrackListener.onPreviewData(nv21, ftFaceList, currentTrackIdList);}}

　　

大多数设备相机预览数据图像的朝向在横屏时为0度。其他情况按逆时针依次增加90度，因此人脸框的绘制需要做同步转化。CameraID为0时，也就是后置摄像头情况，相机预览数据的显示为原画面，而CameraID为1时，也就是前置摄像头情况，相机的预览画面显示为镜像画面，适配的代码：

/**     * @param rect          FT人脸框     * @param previewWidth  相机预览的宽度     * @param previewHeight 相机预览高度     * @param canvasWidth   画布的宽度     * @param canvasHeight  画布的高度     * @param cameraOri     相机预览方向     * @param mCameraId     相机ID     * @return     */    static Rect adjustRect(Rect rect, int previewWidth, int previewHeight, int canvasWidth, int canvasHeight, int cameraOri, int mCameraId) {        if (rect == null) {            return null;        }        if (canvasWidth < canvasHeight) {            int t = previewHeight;            previewHeight = previewWidth;            previewWidth = t;        }         float horizontalRatio;        float verticalRatio;        if (cameraOri == 0 || cameraOri == 180) {            horizontalRatio = (float) canvasWidth / (float) previewWidth;            verticalRatio = (float) canvasHeight / (float) previewHeight;        } else {            horizontalRatio = (float) canvasHeight / (float) previewHeight;            verticalRatio = (float) canvasWidth / (float) previewWidth;        }        rect.left *= horizontalRatio;        rect.right *= horizontalRatio;        rect.top *= verticalRatio;        rect.bottom *= verticalRatio;         Rect newRect = new Rect();         switch (cameraOri) {            case 0:                if (mCameraId == Camera.CameraInfo.CAMERA_FACING_FRONT) {                    newRect.left = canvasWidth - rect.right;                    newRect.right = canvasWidth - rect.left;                } else {                    newRect.left = rect.left;                    newRect.right = rect.right;                }                newRect.top = rect.top;                newRect.bottom = rect.bottom;                break;            case 90:                newRect.right = canvasWidth - rect.top;                newRect.left = canvasWidth - rect.bottom;                if (mCameraId == Camera.CameraInfo.CAMERA_FACING_FRONT) {                    newRect.top = canvasHeight - rect.right;                    newRect.bottom = canvasHeight - rect.left;                } else {                    newRect.top = rect.left;                    newRect.bottom = rect.right;                }                break;            case 180:                newRect.top = canvasHeight - rect.bottom;                newRect.bottom = canvasHeight - rect.top;                if (mCameraId == Camera.CameraInfo.CAMERA_FACING_FRONT) {                    newRect.left = rect.left;                    newRect.right = rect.right;                } else {                    newRect.left = canvasWidth - rect.right;                    newRect.right = canvasWidth - rect.left;                }                break;            case 270:                newRect.left = rect.top;                newRect.right = rect.bottom;                if (mCameraId == Camera.CameraInfo.CAMERA_FACING_FRONT) {                    newRect.top = rect.left;                    newRect.bottom = rect.right;                } else {                    newRect.top = canvasHeight - rect.right;                    newRect.bottom = canvasHeight - rect.left;                }                break;            default:                break;        }        return newRect;    }

　　

由于FR引擎不支持多线程调用，因此只能串行执行，若需要更高效的实现，可创建多个FREngine实例进行任务分配。

FR线程队列：

private LinkedBlockingQueue
     
       faceRecognizeRunnables = new LinkedBlockingQueue
      
       (MAX_FRTHREAD_COUNT);
      
     

　　

FR线程：

public class FaceRecognizeRunnable implements Runnable {private Rect faceRect;private int width;private int height;private int format;private int ori;private Integer requestId;private byte[]nv21Data;public FaceRecognizeRunnable(byte[]nv21Data,Rect faceRect, int width, int height, int format, int ori, Integer requestId) {if (nv21Data==null) {return;}this.nv21Data = new byte[nv21Data.length];System.arraycopy(nv21Data,0,this.nv21Data,0,nv21Data.length);this.faceRect = new Rect(faceRect);this.width = width;this.height = height;this.format = format;this.ori = ori;this.requestId = requestId;}@Overridepublic void run() {if (faceTrackListener!=null && nv21Data!=null) {if (frEngine != null) {AFR_FSDKFace frFace = new AFR_FSDKFace();int frCode = frEngine.AFR_FSDK_ExtractFRFeature(nv21Data, width, height, format, faceRect, ori, frFace).getCode();if (frCode == 0) {faceTrackListener.onFaceFeatureInfoGet(frFace, requestId);} else {faceTrackListener.onFaceFeatureInfoGet(null, requestId);faceTrackListener.onFail(new Exception("fr failed errorCode is " + frCode));}nv21Data = null;}else {faceTrackListener.onFaceFeatureInfoGet(null, requestId);faceTrackListener.onFail(new Exception("fr failed ,frEngine is null" ));}if (faceRecognizeRunnables.size()>0){executor.execute(faceRecognizeRunnables.poll());}}}}

　　

上下帧是否为相同人脸的判断（trackID刷新）：

 

/*** 刷新trackId** @param ftFaceList 传入的人脸列表*/public void refreshTrackId(List
     
       ftFaceList) {currentTrackIdList.clear();//每项预先填充-1for (int i = 0; i < ftFaceList.size(); i++) {currentTrackIdList.add(-1);}//前一次无人脸现在有人脸，填充新增TrackIdif (formerTrackIdList.size() == 0) {for (int i = 0; i < ftFaceList.size(); i++) {currentTrackIdList.set(i, ++currentTrackId);}} else {//前后都有人脸,对于每一个人脸框for (int i = 0; i < ftFaceList.size(); i++) {//遍历上一次人脸框for (int j = 0; j < formerFaceRectList.size(); j++) {//若是同一张人脸if (TrackUtil.isSameFace(SIMILARITY_RECT, formerFaceRectList.get(j), ftFaceList.get(i).getRect())) {//记录IDcurrentTrackIdList.set(i, formerTrackIdList.get(j));break;}}}}//上一次人脸框不存在此人脸for (int i = 0; i < currentTrackIdList.size(); i++) {if (currentTrackIdList.get(i) == -1) {currentTrackIdList.set(i, ++currentTrackId);}}formerTrackIdList.clear();formerFaceRectList.clear();for (int i = 0; i < ftFaceList.size(); i++) {formerFaceRectList.add(new Rect(ftFaceList.get(i).getRect()));formerTrackIdList.add(currentTrackIdList.get(i));}}
     

　　

项目地址：https://github.com/wangshengyang1996/FaceTrackDemo

若有不当的地方望指出。