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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

IOS Core Image之二

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

IOS Core Image之二