色调调整与高斯模糊

//色调调整
+ (UIImage *)sepiaToneWithImage:(UIImage *)image intensity:(CGFloat)value {
    CIContext *context = [CIContext contextWithOptions:nil];
    CIImage *cImage = [CIImage imageWithCGImage:image.CGImage];
    CIImage *cResultImage;
    
    CIFilter *sepiaTone = [CIFilter filterWithName:@"CISepiaTone"];
    [sepiaTone setValue:cImage forKey:@"inputImage"];
    [sepiaTone setValue:@(value) forKey:@"inputIntensity"];
    cResultImage = [sepiaTone valueForKey:@"outputImage"];
    
    CGImageRef imageRef = [context createCGImage:cResultImage fromRect:[cResultImage extent]];
    
    UIImage *resultImage = [UIImage imageWithCGImage:imageRef];
    
    CFRelease(imageRef);
    
    return resultImage;
}

//高斯模糊
+ (UIImage *)gaussianBlurWithImage:(UIImage *)image radius:(CGFloat)value {
    CIContext *context = [CIContext contextWithOptions:nil];
    CIImage *cImage = [CIImage imageWithCGImage:image.CGImage];
    CIImage *cResultImage;
    
    CIFilter *gaussianBlur = [CIFilter filterWithName:@"CIGaussianBlur"];
    [gaussianBlur setValue:cImage forKey:@"inputImage"];
    [gaussianBlur setValue:@(value * 10) forKey:@"inputRadius"];
    cResultImage = [gaussianBlur valueForKey:@"outputImage"];
    
    CGImageRef imageRef = [context createCGImage:cResultImage fromRect:[cResultImage extent]];
    
    UIImage *resultImage = [UIImage imageWithCGImage:imageRef];
    
    CFRelease(imageRef);
    
    return resultImage;
}