系統人臉識別：iOS 官方人臉檢測Demo

  1 /**
  2  *  注意：CIFaceFeature 提供的座標都是和CGContext同樣是反方向的，因此如下的畫圖操做都是用了CGContext的方式
  3  */
  4 - (void)faceRegonized {
  5     CIContext *context = [CIContext contextWithOptions:nil];
  6     UIImage *imageInput = [UIImage imageNamed:@"example"];
  7     CIImage *image = [CIImage imageWithCGImage:imageInput.CGImage];
  8    
  9     //設置識別參數
 10     NSDictionary *param = [NSDictionary dictionaryWithObject:CIDetectorAccuracyHigh
 11                                                       forKey:CIDetectorAccuracy];
 12     //聲明一個CIDetector，並設定識別類型
 13     CIDetector* faceDetector = [CIDetector detectorOfType:CIDetectorTypeFace
 14                                                   context:context options:param];//取得識別結果
 15     NSArray *detectResult = [faceDetector featuresInImage:image];
 16 
 17     //開始一個畫布，並將畫布原圖畫到畫布中去
 18     UIGraphicsBeginImageContext(image.size);
 19     CGContextDrawImage(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, image.size.width, image.size.height), image.CGImage);
 20 
 21     for(CIFaceFeature* faceFeature in detectResult) {
 22         //臉部
 23         UIView* faceView = [[UIView alloc] initWithFrame:faceFeature.bounds];
 24         faceView.layer.borderWidth = 1;
 25         faceView.layer.borderColor = [UIColor orangeColor].CGColor;
 26         
 27         CGFloat faceWidth = faceFeature.bounds.size.width;
 28 
 29         
 30          //CIFaceFeature 全部的屬性
 31         NSLog(@"-------------------------------------\n");
 32         NSLog(@"faceBounds = %@",NSStringFromCGRect(faceFeature.bounds));
 33         NSLog(@"face hasLeftEyePosition = %d",faceFeature.hasLeftEyePosition);
 34         NSLog(@"face leftEyePosition = %@",NSStringFromCGPoint(faceFeature.leftEyePosition));
 35         NSLog(@"face hasRightEyePosition = %d",faceFeature.hasRightEyePosition);
 36         NSLog(@"face rightEyePosition = %@",NSStringFromCGPoint(faceFeature.rightEyePosition));
 37         NSLog(@"face hasMouthPosition = %d",faceFeature.hasMouthPosition);
 38         NSLog(@"face mouthPosition = %@",NSStringFromCGPoint(faceFeature.mouthPosition));
 39         NSLog(@"face hasTrackingID = %d",faceFeature.hasTrackingID);
 40         NSLog(@"face trackingID = %d",faceFeature.trackingID);
 41         NSLog(@"face hasTrackingFrameCount = %d",faceFeature.hasTrackingFrameCount);
 42         NSLog(@"face trackingFrameCount = %d",faceFeature.trackingFrameCount);
 43         NSLog(@"face hasFaceAngle = %d",faceFeature.hasFaceAngle);
 44         NSLog(@"face faceAngle = %f",faceFeature.faceAngle);
 45         NSLog(@"face hasSmile = %d",faceFeature.hasSmile);
 46         NSLog(@"face leftEyeClosed = %d",faceFeature.leftEyeClosed);
 47         NSLog(@"face rightEyeClosed = %d",faceFeature.rightEyeClosed);
 48         NSLog(@"\n-------------------------------------");
 49        
 50         //畫一個矩形出識別出來的臉部的方位
 51         UIBezierPath *path = [UIBezierPath bezierPath];
 52         CGPoint point = faceFeature.bounds.origin;
 53         CGSize size = faceFeature.bounds.size;
 54         [path moveToPoint:point];
 55         [path addLineToPoint:CGPointMake(point.x + size.width, point.y)];
 56         [path addLineToPoint:CGPointMake(point.x + size.width, point.y + size.height)];
 57         [path addLineToPoint:CGPointMake(point.x, point.y+ size.height)];
 58         [path addLineToPoint:point];
 59         [[UIColor redColor] setStroke];
 60         [path stroke];
 61        
 62         [[UIColor redColor] setStroke];
 63         [path stroke];
 64 
 65         //左眼
 66         if (faceFeature.hasLeftEyePosition) {
 67             [self drawCycleAtPoint:faceFeature.leftEyePosition withRadius:faceWidth*0.1];
 68         }
 69        
 70         //右眼
 71         if (faceFeature.hasRightEyePosition) {
 72              [self drawCycleAtPoint:faceFeature.rightEyePosition withRadius:faceWidth*0.1];
 73         }
 74         //嘴巴
 75         if (faceFeature.hasMouthPosition) {
 76              [self drawCycleAtpoint:faceFeature.mouthPosition withRadius:faceWidth*0.2];
 77         }
 78     }
 79 
 80      //得到全部在原圖中圈出來臉以後最後的圖片，此時的圖片是反方向的
 81     UIImage *tempImage = UIGraphicsGetImageFromCurrentImageContext();
 82    
 83     //將畫布清空，並把放方向的圖片用CG的方式畫到原圖中去（CG畫出來的東西都是原來的反方向，並非個好方法，實際開發中用別的方法）
 84     CGContextClearRect(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, image.size.width, image.size.height));
 85     CGContextDrawImage(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, image.size.width, image.size.height), tempImage.CGImage);
 86    
 87     //得到重畫以後的圖片，並結束畫布
 88     tempImage = UIGraphicsGetImageFromCurrentImageContext();
 89     UIGraphicsEndImageContext();
 90    
 91     //將最終的圖片放到View中去
 92     [self.imageView setImage:tempImage];
 93 }
 94 
 95 - (void)drawCycleAtPoint:(CGPoint)point withRadius:(CGFloat)radius {
 96     /*畫圓*/
 97     //邊框圓
 98     CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(),1,0,0,1.0);//畫筆線的顏色
 99     CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 1.0);//線的寬度
100     //void CGContextAddArc(CGContextRef c,CGFloat x, CGFloat y,CGFloat radius,CGFloat startAngle,CGFloat endAngle, int clockwise)1弧度＝180°/π （≈57.3°） 度＝弧度×180°/π 360°＝360×π/180 ＝2π 弧度
101     // x,y爲圓點座標，radius半徑，startAngle爲開始的弧度，endAngle爲 結束的弧度，clockwise 0爲順時針，1爲逆時針。
102     CGContextAddArc(UIGraphicsGetCurrentContext(), point.x, point.y, radius, 0, 2*M_PI, 0); //添加一個圓
103     CGContextDrawPath(UIGraphicsGetCurrentContext(), kCGPathStroke); //繪製路徑
104 }