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: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 <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(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。