我试图在iOS 6上使用CoreImage模糊图像,而没有明显的黑色边框.Apple文档声明使用CIAffineClamp过滤器可以实现此目的,但我无法从过滤器获取输出图像.这是我尝试过的,但不幸的是,当我访问[clampFilter outputImage]时会创建一个空图像.如果我只执行模糊,则会生成图像,但使用黑色边框.
CIImage *inputImage = [[CIImage alloc] initWithCGImage:self.CGImage];
CIContext *context = [CIContext contextWithOptions:nil];
CGAffineTransform transform = CGAffineTransformIdentity;
CIFilter *clampFilter = [CIFilter filterWithName:@"CIAffineClamp"];
[clampFilter setValue:inputImage forKey:kCIInputImageKey];
[clampFilter setValue:[NSValue valueWithBytes:&transform objCType:@encode(CGAffineTransform)] forKey:@"inputTransform"];
CIImage *outputImage = [clampFilter outputImage];
CIFilter *blurFilter = [CIFilter filterWithName:@"CIGaussianBlur"
keysAndValues:kCIInputImageKey, outputImage, @"inputRadius", [NSNumber numberWithFloat:radius], nil];
outputImage = [blurFilter outputImage];
CGImageRef cgimg = [context createCGImage:outputImage fromRect:[outputImage extent]];
UIImage *blurredImage = [UIImage imageWithCGImage:cgimg];
CGImageRelease(cgimg);
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