ios模糊效果和高斯滤镜

这是不太常用到的，记下拉方便自己查找。

模糊效果：

UIImageView *bgImageView = [[UIImageView alloc]initWithFrame:self.view.bounds];

    bgImageView.image= [UIImageimageNamed:@"bg_image"];

    [self.viewaddSubview:bgImageView];

    UIBlurEffect *effect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleRegular];

    UIVisualEffectView *visualView = [[UIVisualEffectView alloc]initWithEffect:effect];

    visualView.frame= bgImageView.bounds;

    [bgImageViewaddSubview:visualView];

高斯滤镜：

CIImage *inputImage = [CIImage imageWithCGImage:[UIImage imageNamed:@"bg_image"].CGImage];

    // 2、构建一个滤镜图表

    CIColor*sepiaColor = [CIColorcolorWithRed:0green:0blue:1.0];

    // 2.1 先构建一个 CIColorMonochrome 滤镜，并配置输入图像与滤镜参数

    CIFilter *inputFilter = [CIFilter filterWithName:@"CIColorMonochrome" withInputParameters:@{@"inputColor":sepiaColor,@"inputIntensity":@0.3}];

    [inputFiltersetValue:inputImageforKey:@"inputImage"];

    // 2.2 先构建一个 CIVignette 滤镜

    CIFilter *vignetteFilter = [CIFilter filterWithName:@"CIVignette" withInputParameters:@{@"inputRadius" : @2.0,@"inputIntensity" :@0.5}];

    [vignetteFiltersetValue:inputFilter.outputImageforKey:@"inputImage"];// 以monochromeFilter的输出来作为输入

    // 3、得到一个滤镜处理后的图片，并转换至 UIImage

    // 创建一个 CIContext

    CIContext*ciContext = [CIContextcontextWithOptions:nil];

    // 将 CIImage 过渡到 CGImageRef 类型

    CGImageRefcgImage = [ciContextcreateCGImage:vignetteFilter.outputImagefromRect:inputImage.extent];

    // 最后转换为 UIImage 类型

    UIImage*uiImage = [UIImageimageWithCGImage:cgImage];

    UIImageView*imgaeView = [[UIImageViewalloc]initWithImage:uiImage];

    imgaeView.frame=self.view.frame;

    [self.viewaddSubview:imgaeView];

参考链接：https://www.jianshu.com/p/3b56d921dfb6