iOS CoreImage进行人脸检测

利用CoreImage进行简单的人脸检测，对于要求不高的需求还是能够满足的。主要代码如下：

一些参数

#import "ViewController.h"

typedef NS_ENUM(NSInteger,ZWViewType){
ZWViewType_eyes,
ZWViewType_mouth
};

//设置颜色
#define ZWEyesColor [UIColor blueColor]
#define ZWMouthColor [UIColor greenColor]
//设置图层大小比例
#define ZWEyesScale 0.2
#define ZWMouthScale 0.4

@interface ViewController ()

@end

初始化图片，并对图片进行放大处理

- (void)viewDidLoad {
[super viewDidLoad];

UIImage* image = [UIImage imageNamed:@"person.png"];
image = [self strectImageWithImage:image targetSize:CGSizeMake(200, 200)];
UIImageView *imageV = [[UIImageView alloc] initWithImage: image];
[imageV setFrame:CGRectMake(0, 0, image.size.width,image.size.height)];
imageV.center = self.view.center;
[self.view addSubview:imageV];

[self drawFaceWithImageView:imageV];

}

图片放大方法

#pragma mark-放大图片
-(UIImage *)strectImageWithImage:(UIImage *)image targetSize:(CGSize)size{

UIGraphicsBeginImageContext(size);
CGRect thumbnailRect = CGRectZero;
thumbnailRect.origin = CGPointMake(0, 0);
thumbnailRect.size.width  = size.width;
thumbnailRect.size.height = size.height;
[image drawInRect:thumbnailRect];

UIImage * newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

if (newImage) {
return  newImage;
}
return nil;
}

进行人脸识别成功后需要对人脸面部的部位进行坐标转换

#pragma mark-进行人脸识别
-(void)drawFaceWithImageView:(UIImageView *)imageView{

CIImage* ciimage = [CIImage imageWithCGImage:imageView.image.CGImage];
NSDictionary* opts = [NSDictionary dictionaryWithObject:
CIDetectorAccuracyHigh forKey:CIDetectorAccuracy];
CIDetector* detector = [CIDetector detectorOfType:CIDetectorTypeFace
context:nil options:opts];
//所有的人脸数据
NSArray* features = [detector featuresInImage:ciimage];

//得到图片的尺寸
CGSize inputImageSize = [ciimage extent].size;
//初始化transform
CGAffineTransform  transform = CGAffineTransformIdentity;
//设置缩放，
transform = CGAffineTransformScale(transform, 1, -1);
//将图片上移
transform = CGAffineTransformTranslate(transform, 0, -inputImageSize.height);

for (CIFaceFeature *faceFeature in features){
//获取人脸的frame
CGRect faceViewBounds = CGRectApplyAffineTransform(faceFeature.bounds, transform);
//获取人脸范围的宽
CGFloat faceWidth = faceFeature.bounds.size.width;
//描绘人脸区域
UIView* faceView = [[UIView alloc] initWithFrame:faceViewBounds];
faceView.layer.borderWidth = 1;
faceView.layer.borderColor = [[UIColor redColor] CGColor];
[imageView addSubview:faceView];

if(faceFeature.hasLeftEyePosition){
//获取人左眼对应的point
CGPoint faceViewLeftPoint = CGPointApplyAffineTransform(faceFeature.leftEyePosition, transform);
//添加遮罩
[imageView addSubview:[self createCoverViewWithPoint:faceViewLeftPoint andWith:faceWidth andType:ZWViewType_eyes]];
}

if(faceFeature.hasRightEyePosition){
//获取人右眼对应的point
CGPoint faceViewRightPoint = CGPointApplyAffineTransform(faceFeature.rightEyePosition, transform);
//添加遮罩
[imageView addSubview:[self createCoverViewWithPoint:faceViewRightPoint andWith:faceWidth andType:ZWViewType_eyes]];
}

if(faceFeature.hasMouthPosition){
//获取人嘴巴对应的point
CGPoint faceViewMouthPoint = CGPointApplyAffineTransform(faceFeature.mouthPosition, transform);
//添加遮罩
[imageView addSubview:[self createCoverViewWithPoint:faceViewMouthPoint andWith:faceWidth andType:ZWViewType_mouth]];
}

}
}

添加View的代码：

#pragma mark-绘制遮罩
-(UIView *)createCoverViewWithPoint:(CGPoint)point andWith:(CGFloat)width andType:(ZWViewType)type{

CGFloat newWidth = 0;
UIColor *color = nil;
switch (type) {
case ZWViewType_eyes:
newWidth = width * ZWEyesScale;
color= ZWEyesColor;
break;
case ZWViewType_mouth:
newWidth = width * ZWMouthScale;
color= ZWMouthColor;
break;
default:
break;
}
UIView* cover = [[UIView alloc] initWithFrame:
CGRectMake( 0, 0, newWidth, newWidth)];
[cover setBackgroundColor:[color colorWithAlphaComponent:0.3]];
[cover setCenter:point];
cover.layer.cornerRadius = newWidth/2;
return  cover;
}

看下效果图：

效果图1：



效果图2：



效果图3:



//进行人脸面部表情位置计算的第二种方式，无需进行位置的偏移，直接计算出各个部位的frame，需要保持图片的frame和imageView的frame一致。

for (CIFaceFeature *f in features){
//旋转180，仅y
CGRect aRect = f.bounds;
//利用翻转的对称性计算出y值
aRect.origin.y = self.imageView.bounds.size.height - aRect.size.height - aRect.origin.y;//

UIView *vv = [[UIView alloc]initWithFrame:aRect];
vv.backgroundColor = [UIColor redColor];
vv.alpha = 0.6;
[self.imageView addSubview:vv];

if (f.hasLeftEyePosition){

UIView *vv = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 10, 10)];
//旋转180，仅y
CGPoint newCenter =  f.leftEyePosition;
//利用翻转的对称性计算出y值
newCenter.y = self.imageView.bounds.size.height-newCenter.y;
vv.center = newCenter;

vv.backgroundColor = [UIColor yellowColor];
vv.alpha = 0.6;
[self.imageView addSubview:vv];

}
if (f.hasRightEyePosition){
UIView *vv = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 10, 10)];
//旋转180，仅y
CGPoint newCenter =  f.rightEyePosition;
//利用翻转的对称性计算出y值
newCenter.y = self.imageView.bounds.size.height-newCenter.y;
vv.center = newCenter；
vv.backgroundColor = [UIColor blueColor];
vv.alpha = 0.6;
[self.imageView addSubview:vv];

}
if (f.hasMouthPosition){
UIView *vv = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 10, 10)];
//旋转180，仅y
CGPoint newCenter =  f.mouthPosition;
newCenter.y = self.imageView.bounds.size.height-newCenter.y;
vv.center = newCenter;
vv.backgroundColor = [UIColor greenColor];
vv.alpha = 0.6;
[self.imageView addSubview:vv];
}
}