IOS Core Image之二

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 <CoreImage/CoreImage.h>
@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:];
    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 <CoreImage/CoreImage.h>
@interface ViewController ()
 
@end
 
@implementation ViewController
 
- (void)viewDidLoad {
    [super viewDidLoad];
    UIImage* image = [UIImage imageNamed:@"psu.jpg"];
    UIImageView *testImage = [[UIImageView alloc] initWithImage: image];
    [testImage setTransform:CGAffineTransformMakeScale(, -)];
    [[[UIApplication sharedApplication] delegate].window setTransform:
     CGAffineTransformMakeScale(, -)];
 
    [testImage setFrame:CGRectMake(, , 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。