一:簡介
最近項目在做了身份證銀行卡識別之后,開始實現(xiàn)人臉識別和活體識別,其中人臉識別包括人臉入庫、人臉查找、人臉1:N對比、人臉N:N對比,另外活體識別運用在安全登錄功能。
大家都熟知的支付寶使用face++ 的服務來實現(xiàn)人臉識別,在實際項目中使用了訊飛的人臉識別SDK進行二次封裝來實現(xiàn)活體識別。主要實現(xiàn)了張嘴和搖頭兩個活體動作的識別。據(jù)我所知,訊飛的服務是基于face++,識別率還是很高,并且iOS和Android都對應有封裝好的SDK。
在實際運用中,有很多app為了高度保證用戶使用的安全問題,除了常規(guī)的賬號密碼登錄之外,相繼實現(xiàn)了指紋登錄,手勢登錄,第三方登陸(QQ、微信、支付寶)、刷臉登錄,接下里我就和大家分享一下如何實現(xiàn)人臉識別的活體檢測,這是實現(xiàn)刷臉登錄最基礎的實現(xiàn)。
另外,這些博文都是來源于我日常開發(fā)中的技術總結,在時間允許的情況下,我會針對技術點分別分享iOS、Android兩個版本,盡量附上demo以供大家參考,如果有其他技術點需要,可在文章后留言,我會盡全力幫助大家。
二:實現(xiàn)思路分析
點擊識別按鈕,調用相機
CameraRules類,檢測相機權限
初始化頁面,創(chuàng)建攝像頁面,創(chuàng)建張嘴數(shù)據(jù)和搖頭數(shù)據(jù)
開啟識別,臉部框識別
臉部部位識別,臉部識別判斷是否檢測到人臉
檢測到人臉之后,判斷位置
位置判斷合適,判斷是否張嘴
張嘴判斷完畢,驗證是否搖頭
搖頭判斷完畢,3秒倒計時拍照
拍照完畢,選擇重拍或者上傳圖片
選擇重拍重復5-9步驟,選擇上傳將圖片數(shù)據(jù)回調
數(shù)據(jù)clean
三:實現(xiàn)源碼分析
根據(jù)實現(xiàn)思路分析,一步步進行編碼實現(xiàn):
1. 點擊識別按鈕,調用相機
if([CameraRules isCapturePermissionGranted]){
[self setDeviceAuthorized:YES];
}
else{
dispatch_async(dispatch_get_main_queue(), ^{
NSString* info=@"沒有相機權限";
[self showAlert:info];
[self setDeviceAuthorized:NO];
});
}
2. CameraRules類,檢測相機權限
//檢測相機權限
+(BOOL)isCapturePermissionGranted{
if([AVCaptureDevice respondsToSelector:@selector(authorizationStatusForMediaType:)]){
AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
if(authStatus ==AVAuthorizationStatusRestricted || authStatus ==AVAuthorizationStatusDenied){
return NO;
}
else if(authStatus==AVAuthorizationStatusNotDetermined){
dispatch_semaphore_t sema = dispatch_semaphore_create(0);
__block BOOL isGranted=YES;
[AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
isGranted=granted;
dispatch_semaphore_signal(sema);
}];
dispatch_semaphore_wait(sema, DISPATCH_TIME_FOREVER);
return isGranted;
}
else{
return YES;
}
}
else{
return YES;
}
}
3. 初始化頁面,創(chuàng)建攝像頁面,創(chuàng)建張嘴數(shù)據(jù)和搖頭數(shù)據(jù)
//創(chuàng)建攝像頁面,創(chuàng)建張嘴數(shù)據(jù)和搖頭數(shù)據(jù)
[self faceUI];
[self faceCamera];
[self faceNumber];
4. 開啟識別,臉部框識別
float cx = (left+right)/2;
float cy = (top + bottom)/2;
float w = right - left;
float h = bottom - top;
float ncx = cy ;
float ncy = cx ;
CGRect rectFace = CGRectMake(ncx-w/2 ,ncy-w/2 , w, h);
if(!isFrontCamera){
rectFace=rSwap(rectFace);
rectFace=rRotate90(rectFace, faceImg.height, faceImg.width);
}
BOOL isNotLocation = [self identifyYourFaceLeft:left right:right top:top bottom:bottom];
if (isNotLocation==YES) {
return nil;
}
5. 臉部部位識別,臉部識別判斷是否檢測到人臉
for(id key in keys){
id attr=[landmarkDic objectForKey:key];
if(attr && [attr isKindOfClass:[NSDictionary class]]){
if(!isFrontCamera){
p=pSwap(p);
p=pRotate90(p, faceImg.height, faceImg.width);
}
if (isCrossBorder == YES) {
[self delateNumber];
return nil;
}
p=pScale(p, widthScaleBy, heightScaleBy);
[arrStrPoints addObject:NSStringFromCGPoint(p)];
}
}
6. 檢測到人臉之后,判斷位置動作提醒
if (right - left < 230 || bottom - top < 250) {
self.textLabel.text = @"太遠了";
[self delateNumber];
isCrossBorder = YES;
return YES;
}else if (right - left > 320 || bottom - top > 320) {
self.textLabel.text = @"太近了";
[self delateNumber];
isCrossBorder = YES;
return YES;
}else{
if (isJudgeMouth != YES) {
self.textLabel.text = @"請重復張嘴動作";
[self tomAnimationWithName:@"openMouth" count:2];
if (left < 100 || top < 100 || right > 460 || bottom > 400) {
isCrossBorder = YES;
isJudgeMouth = NO;
self.textLabel.text = @"調整下位置先";
[self delateNumber];
return YES;
}
}else if (isJudgeMouth == YES && isShakeHead != YES) {
self.textLabel.text = @"請重復搖頭動作";
[self tomAnimationWithName:@"shakeHead" count:4];
number = 0;
}else{
takePhotoNumber += 1;
if (takePhotoNumber == 2) {
[self timeBegin];
}
}
isCrossBorder = NO;
}
7. 位置判斷合適,判斷是否張嘴
if (rightX && leftX && upperY && lowerY && isJudgeMouth != YES) {
number ++;
if (number == 1 || number == 300 || number == 600 || number ==900) {
mouthWidthF = rightX - leftX < 0 ? abs(rightX - leftX) : rightX - leftX;
mouthHeightF = lowerY - upperY < 0 ? abs(lowerY - upperY) : lowerY - upperY;
NSLog(@"%d,%d",mouthWidthF,mouthHeightF);
}else if (number > 1200) {
[self delateNumber];
[self tomAnimationWithName:@"openMouth" count:2];
}
mouthWidth = rightX - leftX < 0 ? abs(rightX - leftX) : rightX - leftX;
mouthHeight = lowerY - upperY < 0 ? abs(lowerY - upperY) : lowerY - upperY;
NSLog(@"%d,%d",mouthWidth,mouthHeight);
NSLog(@"張嘴前:width=%d,height=%d",mouthWidthF - mouthWidth,mouthHeight - mouthHeightF);
if (mouthWidth && mouthWidthF) {
if (mouthHeight - mouthHeightF >= 20 && mouthWidthF - mouthWidth >= 15) {
isJudgeMouth = YES;
imgView.animationImages = nil;
}
}
}
8. 張嘴判斷完畢,驗證是否搖頭
if ([key isEqualToString:@"mouth_middle"] && isJudgeMouth == YES) {
if (bigNumber == 0 ) {
firstNumber = p.x;
bigNumber = p.x;
smallNumber = p.x;
}else if (p.x > bigNumber) {
bigNumber = p.x;
}else if (p.x < smallNumber) {
smallNumber = p.x;
}
if (bigNumber - smallNumber > 60) {
isShakeHead = YES;
[self delateNumber];
}
}
9. 搖頭判斷完畢,3秒倒計時拍照
if(timeCount >= 1)
{
self.textLabel.text = [NSString stringWithFormat:@"%ld s后拍照",(long)timeCount];
}
else
{
[theTimer invalidate];
theTimer=nil;
[self didClickTakePhoto];
}
10. 拍照完畢,選擇重拍或者上傳圖片
-(void)didClickPhotoAgain
{
[self delateNumber];
[self.previewLayer.session startRunning];
self.textLabel.text = @"請調整位置";
[backView removeFromSuperview];
isJudgeMouth = NO;
isShakeHead = NO;
}
11. 選擇重拍重復5-9步驟,選擇上傳將圖片數(shù)據(jù)回調
-(void)didClickUpPhoto
{
//上傳照片成功
[self.faceDelegate sendFaceImage:imageView.image];
[self.navigationController popViewControllerAnimated:YES];
}
12. 數(shù)據(jù)clean
-(void)delateNumber
{
number = 0;
takePhotoNumber = 0;
mouthWidthF = 0;
mouthHeightF = 0;
mouthWidth = 0;
mouthHeight = 0;
smallNumber = 0;
bigNumber = 0;
firstNumber = 0;
imgView.animationImages = nil;
imgView.image = [UIImage imageNamed:@"shakeHead0"];
}
四:訊飛SDK下載及配置
1. SDK下載
因為項目中使用到訊飛人臉識別SDK,需要去訊飛開放平臺創(chuàng)建應用,下載SDK。

2. 添加系統(tǒng)庫
將開發(fā)工具包中l(wèi)ib目錄下的iflyMSC.framework添加到工程中。同時請將Demo中依賴的其他庫也添加到工程中。 按下圖示例添加 SDK 所需要的 iOS系統(tǒng)庫:

3. 設置Bitcode
在Targets - Build Settings 中搜索Bitcode 即可,找到相應選項,設置為NO,如下圖:

4. 用戶隱私權限配置
在Info.plist 中增加下圖設置:

五:項目實際使用
1. 下載demo
下載demo,將demo中FBYFaceData文件夾引入項目中。
2. 在項目中引入FBYFaceRecognitionViewController
#import "FBYFaceRecognitionViewController.h"
3. 在項目識別按鈕的點擊事件中添加代碼
-(void)pushToFaceStreamDetectorVC
{
FBYFaceRecognitionViewController *faceVC = [[FBYFaceRecognitionViewController alloc]init];
faceVC.faceDelegate = self;
[self.navigationController pushViewController:faceVC animated:YES];
}
4. 圖片回調函數(shù)
-(void)sendFaceImage:(UIImage *)faceImage
{
NSLog(@"圖片上傳成功");
}
- (void)sendFaceImageError {
NSLog(@"圖片上傳失敗");
}