给图片增加高斯模糊效果

前一阵研究了图片的滤镜效果，今天单独把高斯模糊的拿出来，供小伙伴们一起学习。

高斯模糊的效果其实灰常简单，苹果这边已经给了一些现成的封装CIFilter，下面一起来看一看代码吧~

//
//  ViewController.m
//  GS
//
//  Created by a111 on 16/3/7.
//  Copyright © 2016年 司小文. All rights reserved.
//

#import "ViewController.h"
#define nav 64 //导航条高度
#define imgViewH 200 //图片高度

@interface ViewController (){
CIFilter *filter;//全局filter
UIImageView *_imgView_Top;//上方图片
UIImage *_img_original;//原始图片
float radius;//高斯模糊度
}

@end

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];
self.title = @"高斯模糊demo";

//高斯模糊度 （这个数值由你自己设定，越大模糊度越高）
radius = 10.;

//原始图片img
_img_original = [UIImage imageNamed:@"20140622212336_N284Y.jpg"];

//图片
_imgView_Top = [[UIImageView alloc] initWithFrame:CGRectMake(0, nav, self.view.frame.size.width,imgViewH)];
_imgView_Top.image = _img_original;
[self.view addSubview:_imgView_Top];

//高斯模糊
filter = [CIFilter filterWithName:@"CIGaussianBlur"];
[filter setValue:@(radius) forKey:@"inputRadius"];

//将图片转换成文件
NSData *imageData = UIImagePNGRepresentation(_img_original);

//将文件转换成CIImage
CIImage *beginImage =[CIImage imageWithData:imageData];

//模式
[filter setValue:beginImage forKey:kCIInputImageKey];

//渲染并输出CIImage
CIImage *outputImage = [filter outputImage];

//获取绘制上下文
CIContext *context = [CIContext contextWithOptions:nil];

//创建CGImage句柄
CGImageRef cgimg = [context createCGImage: outputImage fromRect:[beginImage extent]];

//获取图片
UIImage *newImage = [UIImage imageWithCGImage:cgimg];

//释放CGImage句柄
CGImageRelease(cgimg);

//赋值img
_imgView_Top.image = newImage;

// Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

@end

下图为模拟器效果



demo链接 ：高斯模糊--司小文（提取码：978c）

感谢观看，学以致用更感谢。