在上篇博客IOS Core Image之一中了解了下CIImage、CIFilter、CIContext三个类的使用,这篇了解下滤镜链(多滤镜)和人脸检测(不是人脸识别)。

一、多滤镜

1.有些效果不只是一个滤镜能完成的，需要多个滤镜叠加,让一个滤镜的outputImage作为另一个滤镜的inputImage。

在下面的代码中，给图片加了两个滤镜效果一个高斯模糊一个旋转。

#import "ViewController.h"#import 
    
     @interface ViewController ()@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];            CIImage *inputImg = [[CIImage alloc]initWithCGImage:[UIImage imageNamed:@"1.jpg"].CGImage];    // 滤镜链合成    CIImage *outputImage = [self oldPhoto:inputImg withAmount:10];    CIContext *context=[CIContext contextWithOptions:nil];    CGImageRef cgimg =[context createCGImage:outputImage fromRect:[outputImage extent]];    UIImageView *img = [[UIImageView alloc] initWithFrame:self.view.bounds];    img.backgroundColor = [UIColor redColor];    img.contentMode = UIViewContentModeScaleToFill;    img.image=[UIImage imageWithCGImage:cgimg];    [self.view addSubview:img];    CGImageRelease(cgimg);   }-(CIImage *)oldPhoto:(CIImage *)img withAmount:(float)intensity {        //高斯模糊滤镜    CIFilter *gaussianBlurFilter = [CIFilter filterWithName:@"CIGaussianBlur"];    [gaussianBlurFilter setValue:img forKey:@"inputImage"];    [gaussianBlurFilter setValue: @(intensity) forKey:@"inputRadius"];            //旋转滤镜    CIFilter *affineTransformFilter = [CIFilter filterWithName:@"CIAffineTransform"];    [affineTransformFilter setValue:gaussianBlurFilter.outputImage forKey:@"inputImage"];    [affineTransformFilter setValue: [NSValue valueWithCGAffineTransform:CGAffineTransformMakeRotation(intensity)] forKey:@"inputTransform"];    return affineTransformFilter.outputImage;}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end
    

2.效果图

二、人脸检测

1.网上有的写的是人脸识别,了解了下发现CoreImage中的算不上人脸识别,也只是检测下人脸的位置,眼睛、嘴巴、是否微笑等,并不能识别出是不是同一个人。这个参考了博客http://blog.csdn.net/wildfireli/article/details/7164628.用自己素颜图(儿童不宜,戴墨镜观看防止亮瞎眼)试了下还算OK。

////  ViewController.m//  CoreImage////  Created by City--Online on 15/11/10.//  Copyright © 2015年 City--Online. All rights reserved.//#import "ViewController.h"#import 
    
     @interface ViewController ()@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    UIImage* image = [UIImage imageNamed:@"psu.jpg"];    UIImageView *testImage = [[UIImageView alloc] initWithImage: image];    [testImage setTransform:CGAffineTransformMakeScale(1, -1)];    [[[UIApplication sharedApplication] delegate].window setTransform:     CGAffineTransformMakeScale(1, -1)];    [testImage setFrame:CGRectMake(0, 0, testImage.image.size.width,                                   testImage.image.size.height)];    [self.view addSubview:testImage];    CIImage* ciimage = [CIImage imageWithCGImage:image.CGImage];//    detectorOfType 检测类型  context画布 options字典    CIDetector *detector=[CIDetector detectorOfType:CIDetectorTypeFace context:nil options:@{CIDetectorAccuracy:CIDetectorAccuracyHigh}];    NSArray *features= [detector featuresInImage:ciimage];    // 在 CIFeature类中有CIFaceFeature、CIRectangleFeature、CIQRCodeFeature、CITextFeature子类    for (CIFaceFeature *faceFeature in features) {        CGFloat faceWidth = faceFeature.bounds.size.width;        if (faceFeature.hasLeftEyePosition) {            [self addViewWithPoint:faceFeature.leftEyePosition withWidth:faceWidth];        }        if (faceFeature.hasRightEyePosition)        {            [self addViewWithPoint:faceFeature.rightEyePosition withWidth:faceWidth];        }        if (faceFeature.hasMouthPosition) {            [self addViewWithPoint:faceFeature.mouthPosition withWidth:faceWidth];        }    }   }-(void)addViewWithPoint:(CGPoint)point withWidth:(float)faceWidth{    UIView* view = [[UIView alloc] initWithFrame:CGRectMake(point.x-faceWidth*0.1,point.y-faceWidth*0.1, faceWidth*0.2, faceWidth*0.2)];    [view setBackgroundColor:[[UIColor blueColor] colorWithAlphaComponent:0.3]];    [view setCenter:point];    view.layer.cornerRadius = faceWidth*0.1;    [self.view  addSubview:view];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end
    

2.效果图

由于清屏网无耻，抄袭我博客并将我头像放在它网上，我就把这图去了

三、高斯模糊第三方

项目背景视图要用高斯模糊的效果,在网上找了个第三方UIImage+ImageEffects,东西也不多,效果又很好。