ios - 通过 objective-c 模糊图像

Question

我想模糊应用程序的 UIImage， 你们有没有 Objective-C 方法来模糊图像？

我试图找到一种方法或技术，但找不到任何东西。请帮忙!

Answer 1

您可以使用核心图像过滤器。 http://developer.apple.com/library/mac/documentation/GraphicsImaging/Reference/CoreImageFilterReference/index.html

看看 https://gist.github.com/betzerra/5988604 中的这个片段

//  Needs CoreImage.framework

- (UIImage *)blurredImageWithImage:(UIImage *)sourceImage{

    //  Create our blurred image
    CIContext *context = [CIContext contextWithOptions:nil];
    CIImage *inputImage = [CIImage imageWithCGImage:sourceImage.CGImage];

    //  Setting up Gaussian Blur
    CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
    [filter setValue:inputImage forKey:kCIInputImageKey];
    [filter setValue:[NSNumber numberWithFloat:15.0f] forKey:@"inputRadius"];
    CIImage *result = [filter valueForKey:kCIOutputImageKey];

    /*  CIGaussianBlur has a tendency to shrink the image a little, this ensures it matches 
     *  up exactly to the bounds of our original image */
    CGImageRef cgImage = [context createCGImage:result fromRect:[inputImage extent]];

    UIImage *retVal = [UIImage imageWithCGImage:cgImage];

    if (cgImage) {
        CGImageRelease(cgImage);
    }

    return retVal;
}