iOS原生人脸识别CIDetector使用

<CoreImage>

#import "ViewController.h"

@interface ViewController ()<UIImagePickerControllerDelegate,UINavigationControllerDelegate>

@property (weak, nonatomic) IBOutlet UIImageView *imageView;

@property(nonatomic,strong)UIImagePickerController *picker;

@end

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.
}

#pragma mark - 相册
- (IBAction)photoButtonClick:(id)sender {

if (!self.picker) {
//初始化uiimagepickercontroller
self.picker = [[UIImagePickerController alloc] init];
//UIImagePickerController是UINavigationControllerDelegate的子类 所以设置代理的时候也要实现navigation的代理

//是否可以编辑
self.picker.allowsEditing = YES;
//设置代理
self.picker.delegate = self;
//设置来源类型
/**UIImagePickerControllerSourceType
UIImagePickerControllerSourceTypePhotoLibrary:进入相册（横向排列）
UIImagePickerControllerSourceTypeCamera：打开相机（必须要真机）
UIImagePickerControllerSourceTypeSavedPhotosAlbum：进入相册(竖向排列)
*/
self.picker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;

}

//先清除上一次人脸识别到的视图
for (UIView *view in self.imageView.subviews) {
[view removeFromSuperview];
}

//弹出相机界面
[self presentViewController:self.picker animated:YES completion:nil];
}

#pragma mark UIImagePickerControllerDelegate

//完成选取
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(nullable NSDictionary<NSString *,id> *)editingInfo
{
NSLog(@"image:%@",image);
self.imageView.image = image;

//开始人脸识别
[self beginDetectorFacewithImage:image];

[picker dismissViewControllerAnimated:YES completion:nil];
}

//取消选取
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
[picker dismissViewControllerAnimated:YES completion:nil];
}

#pragma mark -开始人脸识别

- (void)beginDetectorFacewithImage:(UIImage *)image
{
//1 将UIImage转换成CIImage
CIImage* ciimage = [CIImage imageWithCGImage:image.CGImage];

//缩小图片，默认照片的图片像素很高，需要将图片的大小缩小为我们现实的ImageView的大小，否则会出现识别五官过大的情况
float factor = self.imageView.bounds.size.width/image.size.width;
ciimage = [ciimage imageByApplyingTransform:CGAffineTransformMakeScale(factor, factor)];

//2.设置人脸识别精度
NSDictionary* opts = [NSDictionary dictionaryWithObject:
CIDetectorAccuracyHigh forKey:CIDetectorAccuracy];
//3.创建人脸探测器
CIDetector* detector = [CIDetector detectorOfType:CIDetectorTypeFace
context:nil options:opts];
//4.获取人脸识别数据
NSArray* features = [detector featuresInImage:ciimage];
//5.分析人脸识别数据
for (CIFaceFeature *faceFeature in features){

//注意坐标的换算，CIFaceFeature计算出来的坐标的坐标系的Y轴与iOS的Y轴是相反的,需要自行处理

// 标出脸部
CGFloat faceWidth = faceFeature.bounds.size.width;
UIView* faceView = [[UIView alloc] initWithFrame:faceFeature.bounds];
faceView.frame = CGRectMake(faceView.frame.origin.x, self.imageView.bounds.size.height-faceView.frame.origin.y - faceView.bounds.size.height, faceView.frame.size.width, faceView.frame.size.height);
faceView.layer.borderWidth = 1;
faceView.layer.borderColor = [[UIColor redColor] CGColor];
[self.imageView addSubview:faceView];
// 标出左眼
if(faceFeature.hasLeftEyePosition) {
UIView* leftEyeView = [[UIView alloc] initWithFrame:
CGRectMake(faceFeature.leftEyePosition.x-faceWidth*0.15,
self.imageView.bounds.size.height-(faceFeature.leftEyePosition.y-faceWidth*0.15)-faceWidth*0.3, faceWidth*0.3, faceWidth*0.3)];
[leftEyeView setBackgroundColor:[[UIColor blueColor] colorWithAlphaComponent:0.3]];
//            [leftEyeView setCenter:faceFeature.leftEyePosition];
leftEyeView.layer.cornerRadius = faceWidth*0.15;
[self.imageView  addSubview:leftEyeView];
}
// 标出右眼
if(faceFeature.hasRightEyePosition) {
UIView* leftEye = [[UIView alloc] initWithFrame:
CGRectMake(faceFeature.rightEyePosition.x-faceWidth*0.15,
self.imageView.bounds.size.height-(faceFeature.rightEyePosition.y-faceWidth*0.15)-faceWidth*0.3, faceWidth*0.3, faceWidth*0.3)];
[leftEye setBackgroundColor:[[UIColor blueColor] colorWithAlphaComponent:0.3]];
leftEye.layer.cornerRadius = faceWidth*0.15;
[self.imageView  addSubview:leftEye];
}
// 标出嘴部
if(faceFeature.hasMouthPosition) {
UIView* mouth = [[UIView alloc] initWithFrame:
CGRectMake(faceFeature.mouthPosition.x-faceWidth*0.2,
self.imageView.bounds.size.height-(faceFeature.mouthPosition.y-faceWidth*0.2)-faceWidth*0.4, faceWidth*0.4, faceWidth*0.4)];
[mouth setBackgroundColor:[[UIColor greenColor] colorWithAlphaComponent:0.3]];

mouth.layer.cornerRadius = faceWidth*0.2;
[self.imageView  addSubview:mouth];
}

}
}

- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

@end

CIFaceFeature