Does iOS 5 support blur CoreImage fiters?

Question

According to the documentation it should support blurring, note the "Available in iOS 5.0 and later":

CIFilter Class Reference

But according to the device, it doesn't:

[CIFilter filterNamesInCategory:kCICategoryBlur]; 

returns nothing.

According to the following only these filters are available on my iPhone and Simulator (which are both running 5.0):

[CIFilter filterNamesInCategory:kCICategoryBuiltIn]  CIAdditionCompositing, CIAffineTransform, CICheckerboardGenerator, CIColorBlendMode, CIColorBurnBlendMode, CIColorControls, CIColorCube, CIColorDodgeBlendMode, CIColorInvert, CIColorMatrix, CIColorMonochrome, CIConstantColorGenerator, CICrop, CIDarkenBlendMode, CIDifferenceBlendMode, CIExclusionBlendMode, CIExposureAdjust, CIFalseColor, CIGammaAdjust, CIGaussianGradient, CIHardLightBlendMode, CIHighlightShadowAdjust, CIHueAdjust, CIHueBlendMode, CILightenBlendMode, CILinearGradient, CILuminosityBlendMode, CIMaximumCompositing, CIMinimumCompositing, CIMultiplyBlendMode, CIMultiplyCompositing, CIOverlayBlendMode, CIRadialGradient, CISaturationBlendMode, CIScreenBlendMode, CISepiaTone, CISoftLightBlendMode, CISourceAtopCompositing, CISourceInCompositing, CISourceOutCompositing, CISourceOverCompositing, CIStraightenFilter, CIStripesGenerator, CITemperatureAndTint, CIToneCurve, CIVibrance, CIVignette, CIWhitePointAdjust 

Answer 1

While Core Image on iOS 5.0 lacks blur filters, there is still a way to get GPU-accelerated blurs of images and video. My open source GPUImage framework has multiple blur types, including Gaussian (using the GPUImageGaussianBlurFilter for a general Gaussian or the GPUImageFastBlurFilter for a hardware-optimized 9-hit Gaussian), box (using a GPUImageBoxBlurFilter), median (using a GPUImageMedianFilter), and a bilateral blur (using a GPUImageBilateralBlurFilter).

I describe the shaders used to pull off the hardware-optimized Gaussian blur in this answer, and you can examine the code I use for the rest within the framework. These filters run tens of times faster than any CPU-bound routine I've tried yet.

I've also incorporated these blurs into multi-stage processing effects, like unsharp masking, tilt-shift filtering, Canny edge detection, and Harris corner detection, all of which are available as filters within this framework.