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POCIGaussianBlur and CIAffineClamp on iOS 6
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copied!<p>I am trying to blur an image using CoreImage on iOS 6 without having a noticeable black border. <a href="https://developer.apple.com/library/mac/documentation/GraphicsImaging/Reference/CoreImageFilterReference/Reference/reference.html#//apple_ref/doc/filter/ci/CIAffineClamp" rel="noreferrer">Apple documentation</a> states that using a CIAffineClamp filter can achieve this but I'm not able to get an output image from the filter. Here's what I tried, but unfortunately an empty image is created when I access the [clampFilter outputImage]. If I only perform the blur an image is produced, but with the dark inset border.</p> <pre><code>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); </code></pre>

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