图片模糊

Posted 2022-11-28 孤独的菜鸟----

UIImage, CGImageRef, CIImage区别

http://www.jianshu.com/p/aa2557d977ba

1. CoreImage图片模糊

 UIImage *image = [UIImage imageNamed:@"sj_choujiangBG.jpg"];
    /** 模糊处理 coreImage **/
    // 输入图片
    CIImage *inputCIImage = [[CIImage alloc] initWithImage:image];
    // 滤镜设置
    CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
    [filter setValue:inputCIImage forKey:kCIInputImageKey];
    // 输出图片
    CIImage *outCIImage = [filter valueForKey:kCIOutputImageKey];

    // CIImage 对象不可更改，是线程安全
//    CIContext *context = [CIContext contextWithOptions:nil];
//    CGImageRef outCGImage = [context createCGImage:outCIImage fromRect:[outCIImage extent]];
//    UIImage *finalImage = [UIImage imageWithCGImage:outCGImage];

    // 最终图片
    UIImage *finalImage = [UIImage imageWithCIImage:outCIImage];

    /** 模糊图片很耗时间，最好放到子线程中 **/

    UIImageView *imageView = [[UIImageView alloc] initWithFrame:self.view.bounds];
    imageView.contentMode = UIViewContentModeScaleAspectFill;
    imageView.image = finalImage;
    [self.view addSubview:imageView];

2.利用UIImage+ImageEffects分类

原码网址：https://github.com/YouXianMing/UIImageBlur
// 导入文件：UIImage+ImageEffects.h和UIImage+ImageEffects.m

   //1.导入头文件：#import"UIImage+ImageEffects.h"  
   //原始图片  
   UIImage *sourceImage = [UIImage imageNamed:@"normal"];  
   //对图片进行处理(图片渲染用时，应在子线程中，此处未做此处理)  
   UIImage *blurImage = [sourceImage blurImageAtFrame:CGRectMake(0,0,self.view.bounds.size.width,self.view.bounds.size.height)];//设置frame可进行局部模糊  
   //加载图片  
   UIImageView *imageView = [[UIImageView alloc]initWithImage:blurImage];  
   [self.view addSubview:imageView]; 

3.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