更新时间:2023-02-26 20:43:20
我根据您的照片做了一个小例子。我的算法如下:
I have done a small example based on the photo you have there. My algorithm is as follows:
这是这样做的源代码,
@implementation ViewController
- (void)viewDidLoad{
[super viewDidLoad];
UIImageView *imageView = [[UIImageView alloc] init];
imageView.frame = self.view.bounds;
[self.view addSubview:imageView];
imageView.contentMode = UIViewContentModeScaleAspectFit;
UIImage *image = [UIImage imageNamed:@"monogram.jpg"];
imageView.image = [self imageWithBlurredImageWithImage: image andBlurInsetFromBottom: 200 withBlurRadius:3];
}
- (UIImage*)imageWithBlurredImageWithImage:(UIImage*)image andBlurInsetFromBottom:(CGFloat)bottom withBlurRadius:(CGFloat)blurRadius{
UIGraphicsBeginImageContext(image.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextScaleCTM(context, 1, -1);
CGContextTranslateCTM(context, 0, -image.size.height);
CGContextDrawImage(context, CGRectMake(0, 0, image.size.width, image.size.height), image.CGImage);
CGContextDrawImage(context, CGRectMake(0, 0, image.size.width, bottom), [self blurImage: image withBottomInset: bottom blurRadius: blurRadius].CGImage);
image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
- (UIImage*)blurImage:(UIImage*)image withBottomInset:(CGFloat)inset blurRadius:(CGFloat)radius{
image = [UIImage imageWithCGImage: CGImageCreateWithImageInRect(image.CGImage, CGRectMake(0, image.size.height - inset, image.size.width,inset))];
CIImage *ciImage = [CIImage imageWithCGImage:image.CGImage];
CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
[filter setValue:ciImage forKey:kCIInputImageKey];
[filter setValue:@(radius) forKey:kCIInputRadiusKey];
CIImage *outputCIImage = filter.outputImage;
CIContext *context = [CIContext contextWithOptions:nil];
return [UIImage imageWithCGImage: [context createCGImage:outputCIImage fromRect:ciImage.extent]];
}
@end
这是截图结果。