//第一种方式是使用UIVisualEffectView实现

    self.imageView = [[UIImageView alloc] init];

    self.imageView.image = [UIImage imageNamed:@"1.jpg"];

    self.imageView.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);

    [self.view addSubview:self.imageView];

    //样式可以选择

    UIBlurEffect *blur = [UIBlurEffect effectWithStyle:UIBlurEffectStyleDark];

    UIVisualEffectView *effectV = [[UIVisualEffectView alloc] initWithEffect:blur];

    effectV.alpha = 0.7;

    effectV.frame = CGRectMake(0, 0, self.view.frame.size.width / 2, self.view.frame.size.height);

    [self.imageView addSubview:effectV];

//第二种方式使用CoreImage实现

    //Core Image设置模糊之后会在周围产生白边

    UIImage *image = [UIImage imageNamed:@"1.jpg"];

    UIImage *blurImage = [self coreBlueImage:image];

    self.imageView.image = blurImage;

    //返回当前类别下的所有滤镜,更换不同的category会打印不同的滤镜名称

    /*

    CORE_IMAGE_EXPORT NSString * const kCICategoryDistortionEffect;

    CORE_IMAGE_EXPORT NSString * const kCICategoryGeometryAdjustment;

    CORE_IMAGE_EXPORT NSString * const kCICategoryCompositeOperation;

    CORE_IMAGE_EXPORT NSString * const kCICategoryHalftoneEffect;

    CORE_IMAGE_EXPORT NSString * const kCICategoryColorAdjustment;

    CORE_IMAGE_EXPORT NSString * const kCICategoryColorEffect;

    CORE_IMAGE_EXPORT NSString * const kCICategoryTransition;

    CORE_IMAGE_EXPORT NSString * const kCICategoryTileEffect;

    CORE_IMAGE_EXPORT NSString * const kCICategoryGenerator;

    CORE_IMAGE_EXPORT NSString * const kCICategoryReduction NS_AVAILABLE(10_5, 5_0);

    CORE_IMAGE_EXPORT NSString * const kCICategoryGradient;

    CORE_IMAGE_EXPORT NSString * const kCICategoryStylize;

    CORE_IMAGE_EXPORT NSString * const kCICategorySharpen;

    CORE_IMAGE_EXPORT NSString * const kCICategoryBlur;    各种模糊分类

    CORE_IMAGE_EXPORT NSString * const kCICategoryVideo;

    CORE_IMAGE_EXPORT NSString * const kCICategoryStillImage;

    CORE_IMAGE_EXPORT NSString * const kCICategoryInterlaced;

    CORE_IMAGE_EXPORT NSString * const kCICategoryNonSquarePixels;

    CORE_IMAGE_EXPORT NSString * const kCICategoryHighDynamicRange;

    CORE_IMAGE_EXPORT NSString * const kCICategoryBuiltIn;

    CORE_IMAGE_EXPORT NSString * const kCICategoryFilterGenerator NS_AVAILABLE(10_5, 9_0);

    */

    NSArray *filters = [CIFilter filterNamesInCategory:kCICategoryBlur];

    for (NSString *filterName in filters) {

        //我们可以通过filterName创建对应的滤镜对象

        NSLog(@"滤镜名称:%@",filterName);

//        CIFilter *filter = [CIFilter filterWithName:filterName];

//        NSDictionary *attributes = [filter attributes];

//        //获取属性键/值对（在这个字典中我们可以看到滤镜的属性以及对应的key）

//        NSLog(@"filter attributes:%@",attributes);

    }

    /*

    kCICategoryBlur分类下所有滤镜名称

    CIBokehBlur

    CIBoxBlur

    CIDepthBlurEffect

    CIDiscBlur

    CIGaussianBlur

    CIMaskedVariableBlur

    CIMedianFilter

    CIMorphologyGradient

    CIMorphologyMaximum

    CIMorphologyMinimum

    CIMotionBlur

    CINoiseReduction

    CIZoomBlur

    */

使用到如下的方法

- (UIImage *)coreBlueImage:(UIImage *)image {

    //创建输入CIImage对象

    CIImage *inputImage = [CIImage imageWithCGImage:image.CGImage];

    //创建滤镜(可以更换不同的滤镜,滤镜名称可以从以上代码获取

    CIFilter *filter = [CIFilter filterWithName:@"CIBoxBlur"];

    //设置滤镜属性值为默认值

    [filter setDefaults];

    //设置输入图像

    [filter setValue:inputImage forKey:kCIInputImageKey];

    //获取输出图像

    CIImage *result = [filter valueForKey:kCIOutputImageKey];

    //创建CIContex上下文对象

    CIContext *context = [CIContext contextWithOptions:nil];

    CGImageRef outImage = [context createCGImage: result fromRect:[result extent]];

    UIImage *blurImage = [UIImage imageWithCGImage:outImage];

    CGImageRelease(outImage);

    return blurImage;

}

高斯模糊

代码已上传至GitHub

点击下载代码

欢迎star