ios 图片高斯模糊

+(UIImage *)coreBlurImage:(UIImage *)image withBlurNumber:(CGFloat)blur
{
    CIContext *context = [CIContext contextWithOptions:nil];
    CIImage *inputImage= [CIImage imageWithCGImage:image.CGImage];
    //设置filter
    CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
    [filter setValue:inputImage forKey:kCIInputImageKey]; [filter setValue:@(blur) forKey: @"inputRadius"];
    //模糊图片
    CIImage *result=[filter valueForKey:kCIOutputImageKey];
//    CGImageRef outImage=[context createCGImage:result fromRect:[result extent]];//会有白边
    CGImageRef outImage=[context createCGImage:result fromRect:[inputImage extent]];
    UIImage *blurImage=[UIImage imageWithCGImage:outImage];
    CGImageRelease(outImage);
    return blurImage;
}