iOS开发中模糊效果的实现方案

方案一:利用系统的

CoreImage

(滤镜)

重点理解

CIImage

,

CIFilter

,

CIContext

,

CGImageRef

滤镜处理的过程比较慢,会造成加载图片缓慢的现象(等一会才看到图片),尽量放到子线程执行

- (void)viewDidLoad {
[super viewDidLoad];

// 加载一张图片
UIImage *image = [UIImage imageNamed:@"che"];

/**************CoreImage部分**************/

// 1.创建CIImage
CIImage *ciImage = [[CIImage alloc] initWithImage:image];

// 2.创建滤镜CIFilter
CIFilter *blurFilter = [CIFilter filterWithName:@"CIGaussianBlur"];

// 2.1.将CIImage输入到滤镜中
[blurFilter setValue:ciImage forKey:kCIInputImageKey];

// 可以通过该方法查看我们可以设置的值(如模糊度等)
NSLog(@"%@", [blurFilter attributes]);

// 2.2设置模糊度
[blurFilter setValue:@(2) forKey:@"inputRadius"];

// 2.3将处理好的图片输出
CIImage *outCiImage = [blurFilter valueForKey:kCIOutputImageKey];

// 3.CIContext(option参数为nil代表用CPU渲染,若想用GPU渲染请查看此参数)
CIContext *context = [CIContext contextWithOptions:nil];

// 4.获取CGImage句柄
CGImageRef outCGImage = [context createCGImage:outCiImage fromRect:[outCiImage extent]];

// 5.获取最终的图片
UIImage *blurImage = [UIImage imageWithCGImage:outCGImage];

// 6.释放CGImage
CGImageRelease(outCGImage);
/*****************************************/

UIImageView *imageV = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 750 / 2, 1334 / 2)];
imageV.image = blurImage;
imageV.center = self.view.center;
[self.view addSubview:imageV];

}

方案二:利用UIImage+ImageEffects分类

将

UIImage+ImageEffects.h

和

UIImage+ImageEffects.m

文件加载进工程
包含

UIImage+ImageEffects.h

UIImage+ImageEffects

文件路径

#import "ViewController.h"

#import "UIImage+ImageEffects.h"
- (void)viewDidLoad {
[super viewDidLoad];

// 原始图片
UIImage *sourceImage = [UIImage imageNamed:@"che"];

// 对图片进行模糊处理
UIImage *blurImage = [sourceImage blurImageWithRadius:10];

// 加载模糊处理后的图片
UIImageView *imageV = [[UIImageView alloc] initWithImage:blurImage];
[self.view addSubview:imageV];

}

方案三:利用UIVisualEffectView(iOS8)

#import "ViewController.h"

@interface ViewController ()

/** 背景 */
@property (nonatomic, strong) UIScrollView *scrollView;

@end

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];

// 添加展示的背景,用于显示动态模糊(背景能够滚动,便于查看动态的模糊)
self.scrollView = [[UIScrollView alloc] initWithFrame:self.view.bounds];
UIImageView *imageV = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"fengjing"]];
self.scrollView.contentSize = imageV.image.size;
self.scrollView.bounces = NO;
[self.scrollView addSubview:imageV];
[self.view addSubview:self.scrollView];

/***************添加模糊效果***************/
// 1.创建模糊view
UIVisualEffectView *effectView = [[UIVisualEffectView alloc] initWithEffect:[UIBlurEffect effectWithStyle:UIBlurEffectStyleLight]];

// 2.设定模糊View的尺寸
effectView.frame = CGRectMake(0, 100, 375, 200);

// 3.添加到view当中
[self.view addSubview:effectView];

/******************添加显示文本******************/
UILabel *label = [[UILabel alloc] initWithFrame:effectView.bounds];
label.text = @"模糊效果";
label.font = [UIFont systemFontOfSize:40];
label.textAlignment = NSTextAlignmentCenter;

/****************添加模糊效果的子view****************/
// 1.创建出子模糊view
UIVisualEffectView *subEffectView = [[UIVisualEffectView alloc] initWithEffect:[UIVibrancyEffect effectForBlurEffect:(UIBlurEffect *)effectView.effect]];

// 2.设置子模糊view的尺寸
subEffectView.frame = effectView.bounds;

// 3.将子模糊view添加到effectView的contentView上才能显示
[effectView.contentView addSubview:subEffectView];

// 4.添加要显示的view来达到特殊效果
[subEffectView.contentView addSubview:label];

}

@end

方案一,二,三:demo下载地址 http://download.csdn.net/detail/lxl_815520/9436615