Ios oc 人脸拍照功能

iOS Objective-C 中可以使用系统提供的 Core Image 框架来实现人脸拍照功能。具体步骤如下：

1. 导入 Core Image 框架：

#import <CoreImage/CoreImage.h>

2. 创建 AVCaptureSession 实例：

AVCaptureSession *session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPresetPhoto;

3. 创建 AVCaptureDevice 实例：

AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

4. 创建 AVCaptureDeviceInput 实例：

AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
[session addInput:input];

5. 创建 AVCaptureStillImageOutput 实例：

AVCaptureStillImageOutput *output = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *outputSettings = @{AVVideoCodecKey: AVVideoCodecJPEG};
[output setOutputSettings:outputSettings];
[session addOutput:output];

6. 创建 AVCaptureVideoPreviewLayer 实例：

AVCaptureVideoPreviewLayer *previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
previewLayer.frame = self.view.bounds;
[self.view.layer addSublayer:previewLayer];
[session startRunning];

7. 拍照并获取人脸：

AVCaptureConnection *connection = [output connectionWithMediaType:AVMediaTypeVideo];
[output captureStillImageAsynchronouslyFromConnection:connection completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
    UIImage *image = [UIImage imageWithData:[AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer]];
    CIImage *ciImage = [[CIImage alloc] initWithImage:image];
    NSDictionary *options = @{CIDetectorAccuracy: CIDetectorAccuracyHigh};
    CIDetector *detector = [CIDetector detectorOfType:CIDetectorTypeFace context:nil options:options];
    NSArray *features = [detector featuresInImage:ciImage];
    for (CIFaceFeature *feature in features) {
        if (feature.hasLeftEyePosition && feature.hasRightEyePosition && feature.hasMouthPosition) {
            // 人脸拍照成功，可以在这里处理拍照后的操作
        }
    }
}];

以上是一个简单的人脸拍照功能的实现方法，你可以根据实际需求进行修改和优化。