Developing Core Image Filters for ios

Transcription

1 Media #WWDC14 Developing Core Image Filters for ios Session 515 Alexandre Naaman Lead Customizer Tony Chu General Specialist 2014 Apple Inc. All rights reserved. Redistribution or public display not permitted without written permission from Apple.

2 New to ios 8 Write your own kernels Introduced on OS X 10.4, now on ios Main motivation unable to write kernels as a combination of existing filters Use cases - Per pixel effects (e.g., hot pixels, vignette) - Distortions that cannot be represented as a matrix (Droste)

3 Agenda Concepts

4 Agenda Concepts Examples of writing custom kernels

5 Agenda Concepts Examples of writing custom kernels Platform differences

6 Key Concepts

7 Key Concepts Filters perform per pixel operations on an image Sepia Filter Original Result

8 Key Concepts Filters can be chained together for complex effects Sepia Filter Hue Adjust Filter Contrast Filter Original Result

9 Key Concepts Intermediate images are lightweight objects Sepia Filter Hue Adjust Filter Contrast Filter Original Result

10 Key Concepts Each filter has one or more kernel functions Sepia Filter Hue Adjust Filter Contrast Filter Original Result kernel vec4 sepia ( kernel vec4 hue ( kernel vec4 contrast (

11 Key Concepts Kernels concatenated into programs to minimize buffers Concat d Contrast Sepia Filter Original Result kernel vec4 sepia ( kernel vec4 hue ( kernel vec4 contrast (

12 Key Concepts Kernels concatenated into programs to minimize buffers Concat d Contrast Sepia Filter Original Result kernel vec4 sepia ( kernel vec4 hue ( kernel vec4 contrast (

13 Core Image Classes

14 Core Image Classes CIKernel Represents a program written in Core Image s kernel language

15 Core Image Classes CIKernel Represents a program written in Core Image s kernel language CIFilter Has mutable input parameters Uses one or more CIKernels to make a new image based on inputs

16 Core Image Classes CIKernel Represents a program written in Core Image s kernel language CIFilter Has mutable input parameters Uses one or more CIKernels to make a new image based on inputs CIImage An immutable object that represents the recipe for an image Non zero origin (lower left) and possibly infinite bounds

17 Core Image Classes CIKernel Represents a program written in Core Image s kernel language CIFilter Has mutable input parameters Uses one or more CIKernels to make a new image based on inputs CIImage An immutable object that represents the recipe for an image Non zero origin (lower left) and possibly infinite bounds CIContext A object through which Core Image draws results

18 Concepts Starting assumptions void *inputbuffer={ };

19 Concepts Starting assumptions void *inputbuffer={ }; void *outputbuffer={ };

20 Concepts Starting assumptions void *inputbuffer={ }; for (j=0;j<height;j++){ } void *outputbuffer={ };

21 Concepts Starting assumptions void *inputbuffer={ }; for (j=0;j<height;j++){ } } for (i=0;i<width;i++){ void *outputbuffer={ };

22 Concepts Starting assumptions void *inputbuffer={ }; for (j=0;j<height;j++){ } } for (i=0;i<width;i++){ outputbuffer[i][j]= processpixel (inputbuffer[i][j]); void *outputbuffer={ };

23 Concepts Starting assumptions void *inputbuffer={ }; for (j=0;j<height;j++){ } } for (i=0;i<width;i++){ outputbuffer[i][j]= processpixel (inputbuffer[i][j]); void *outputbuffer={ };

24 Concepts Starting assumptions void *inputbuffer={ }; for (j=0;j<height;j++){ } } for (i=0;i<width;i++){ outputbuffer[i][j]= processpixel (inputbuffer[i][j]); void *outputbuffer={ }; CIKernel: processpixel

25 Concepts Starting assumptions void *inputbuffer={ }; for (j=0;j<height;j++){ } } for (i=0;i<width;i++){ outputbuffer[i][j]= processpixel (inputbuffer[i][j]); void *outputbuffer={ }; CIKernel: processpixel CIFilter subclass

26 Concepts Starting assumptions void *inputbuffer={ }; for (j=0;j<height;j++){ } } for (i=0;i<width;i++){ outputbuffer[i][j]= processpixel (inputbuffer[i][j]); void *outputbuffer={ }; CIImage CIKernel: processpixel CIFilter subclass

27 Concepts Starting assumptions void *inputbuffer={ }; for (j=0;j<height;j++){ } } for (i=0;i<width;i++){ outputbuffer[i][j]= processpixel (inputbuffer[i][j]); void *outputbuffer={ }; CIImage other input params CIKernel: processpixel CIFilter subclass

28 Concepts Starting assumptions void *inputbuffer={ }; for (j=0;j<height;j++){ } } for (i=0;i<width;i++){ outputbuffer[i][j]= processpixel (inputbuffer[i][j]); void *outputbuffer={ }; CIImage other input params CIKernel: processpixel CIFilter subclass CIImage

29 Workflow Using Core Image on ios

30 Workflow Using Core Image on ios Create input CIImages

31 Workflow Using Core Image on ios Create input CIImages Subclass CIFilter

32 Workflow Using Core Image on ios Create input CIImages Subclass CIFilter Get output CIImage

33 Workflow Using Core Image on ios Create input CIImages Subclass CIFilter Get output CIImage Use CIContext to render output image (to CGImageRef, EAGL context, etc.)

34 Workflow Using Core Image on ios Create input CIImages Subclass CIFilter Create kernel Apply kernel to input image(s) and pass parameters from filter Get output CIImage Use CIContext to render output image (to CGImageRef, EAGL context, etc.)

35 115 Built-in CIFilters on ios CIAccordianFoldTransition CIAdditionCompositing CIAffineClamp CIAffineTile CIAffineTransform CIAreaHistogram CIBarsSwipeTransition CIBlendWithMask CIBloom CIBumpDistortion CIBumpDistortionLinear CICheckerboardGenerator CICircleSplashDistortion CICircularScreen CICode128BarcodeGenerator CIColorBlendMode CIColorBurnBlendMode CIColorControls CIColorCube CIColorDodgeBlendMode CIColorInvert CIColorMap CIColorMatrix CIColorMonochrome CIColorClamp CIColorCrossPolynomial CIColorPolynomial CIColorPosterize CIConstantColorGenerator CIConvolution3X3 CIConvolution5X5 CIConvolution9Horizontal CIConvolution9Vertical CICopyMachineTransition CICrop CIDarkenBlendMode CIDifferenceBlendMode CIDisintegrateWithMask CIDissolveTransition CIDivideBlendMode CIDotScreen CIEightfoldReflectedTile CIExclusionBlendMode CIExposureAdjust CIFalseColor CIFlashTransition CIFourfoldReflectedTile CIFourfoldTranslatedTile CIGammaAdjust CIGaussianBlur CIGaussianGradient CIGlassDistortion CIGlideReflectedTile CIGloom CIHardLightBlendMode CIHatchedScreen CIHighlightShadowAdjust CIHistogramDisplayFilter CIHoleDistortion CIHueAdjust CIHueBlendMode CILanczosScaleTransform CILightenBlendMode CILightTunnel CILinearBurnBlendMode CILinearDodgeBlendMode CILinearGradient CILineScreen CILuminosityBlendMode CIMaskToAlpha CIMaximumComponent CIMaximumCompositing CIMinimumComponent CIMinimumCompositing CIModTransition CIMultiplyBlendMode CIMultiplyCompositing CIOverlayBlendMode CIPerspectiveCorrection CIPerspectiveTile CIPerspectiveTransform CIPinchDistortion CIPinLightBlendMode CIPixellate CIRadialGradient CIRandomGenerator CISaturationBlendMode CIScreenBlendMode CISepiaTone CISharpenLuminance CISixfoldReflectedTile CISixfoldRotatedTile CISoftLightBlendMode CISourceAtopCompositing CILinearToSRGBToneCurve CISRGBToneCurveToLinear CISourceInCompositing CISourceOutCompositing CISourceOverCompositing CIStarShineGenerator CIStraightenFilter CIStripesGenerator CISubtractBlendMode CISwipeTransition CITemperatureAndTint CIToneCurve CITriangleKaleidoscope CITwelvefoldReflectedTile CITwirlDistortion CIUnsharpMask CIVibrance CIVignette CIVortexDistortion CIWhitePointAdjust CIQRCodeGenerator

36 115 Built-in CIFilters on ios (78 Color) CIAccordianFoldTransition CIAdditionCompositing CIAffineClamp CIAffineTile CIAffineTransform CIAreaHistogram CIBarsSwipeTransition CIBlendWithMask CIBloom CIBumpDistortion CIBumpDistortionLinear CICheckerboardGenerator CICircleSplashDistortion CICircularScreen CICode128BarcodeGenerator CIColorBlendMode CIColorBurnBlendMode CIColorControls CIColorCube CIColorDodgeBlendMode CIColorInvert CIColorMap CIColorMatrix CIColorMonochrome CIColorClamp CIColorCrossPolynomial CIColorPolynomial CIColorPosterize CIConstantColorGenerator CIConvolution3X3 CIConvolution5X5 CIConvolution9Horizontal CIConvolution9Vertical CICopyMachineTransition CICrop CIDarkenBlendMode CIDifferenceBlendMode CIDisintegrateWithMask CIDissolveTransition CIDivideBlendMode CIDotScreen CIEightfoldReflectedTile CIExclusionBlendMode CIExposureAdjust CIFalseColor CIFlashTransition CIFourfoldReflectedTile CIFourfoldTranslatedTile CIGammaAdjust CIGaussianBlur CIGaussianGradient CIGlassDistortion CIGlideReflectedTile CIGloom CIHardLightBlendMode CIHatchedScreen CIHighlightShadowAdjust CIHistogramDisplayFilter CIHoleDistortion CIHueAdjust CIHueBlendMode CILanczosScaleTransform CILightenBlendMode CILightTunnel CILinearBurnBlendMode CILinearDodgeBlendMode CILinearGradient CILineScreen CILuminosityBlendMode CIMaskToAlpha CIMaximumComponent CIMaximumCompositing CIMinimumComponent CIMinimumCompositing CIModTransition CIMultiplyBlendMode CIMultiplyCompositing CIOverlayBlendMode CIPerspectiveCorrection CIPerspectiveTile CIPerspectiveTransform CIPinchDistortion CIPinLightBlendMode CIPixellate CIRadialGradient CIRandomGenerator CISaturationBlendMode CIScreenBlendMode CISepiaTone CISharpenLuminance CISixfoldReflectedTile CISixfoldRotatedTile CISoftLightBlendMode CISourceAtopCompositing CILinearToSRGBToneCurve CISRGBToneCurveToLinear CISourceInCompositing CISourceOutCompositing CISourceOverCompositing CIStarShineGenerator CIStraightenFilter CIStripesGenerator CISubtractBlendMode CISwipeTransition CITemperatureAndTint CIToneCurve CITriangleKaleidoscope CITwelvefoldReflectedTile CITwirlDistortion CIUnsharpMask CIVibrance CIVignette CIVortexDistortion CIWhitePointAdjust CIQRCodeGenerator

37 115 Built-in CIFilters on ios (27 Warps) CIAccordianFoldTransition CIAdditionCompositing CIAffineClamp CIAffineTile CIAffineTransform CIAreaHistogram CIBarsSwipeTransition CIBlendWithMask CIBloom CIBumpDistortion CIBumpDistortionLinear CICheckerboardGenerator CICircleSplashDistortion CICircularScreen CICode128BarcodeGenerator CIColorBlendMode CIColorBurnBlendMode CIColorControls CIColorCube CIColorDodgeBlendMode CIColorInvert CIColorMap CIColorMatrix CIColorMonochrome CIColorClamp CIColorCrossPolynomial CIColorPolynomial CIColorPosterize CIConstantColorGenerator CIConvolution3X3 CIConvolution5X5 CIConvolution9Horizontal CIConvolution9Vertical CICopyMachineTransition CICrop CIDarkenBlendMode CIDifferenceBlendMode CIDisintegrateWithMask CIDissolveTransition CIDivideBlendMode CIDotScreen CIEightfoldReflectedTile CIExclusionBlendMode CIExposureAdjust CIFalseColor CIFlashTransition CIFourfoldReflectedTile CIFourfoldTranslatedTile CIGammaAdjust CIGaussianBlur CIGaussianGradient CIGlassDistortion CIGlideReflectedTile CIGloom CIHardLightBlendMode CIHatchedScreen CIHighlightShadowAdjust CIHistogramDisplayFilter CIHoleDistortion CIHueAdjust CIHueBlendMode CILanczosScaleTransform CILightenBlendMode CILightTunnel CILinearBurnBlendMode CILinearDodgeBlendMode CILinearGradient CILineScreen CILuminosityBlendMode CIMaskToAlpha CIMaximumComponent CIMaximumCompositing CIMinimumComponent CIMinimumCompositing CIModTransition CIMultiplyBlendMode CIMultiplyCompositing CIOverlayBlendMode CIPerspectiveCorrection CIPerspectiveTile CIPerspectiveTransform CIPinchDistortion CIPinLightBlendMode CIPixellate CIRadialGradient CIRandomGenerator CISaturationBlendMode CIScreenBlendMode CISepiaTone CISharpenLuminance CISixfoldReflectedTile CISixfoldRotatedTile CISoftLightBlendMode CISourceAtopCompositing CILinearToSRGBToneCurve CISRGBToneCurveToLinear CISourceInCompositing CISourceOutCompositing CISourceOverCompositing CIStarShineGenerator CIStraightenFilter CIStripesGenerator CISubtractBlendMode CISwipeTransition CITemperatureAndTint CIToneCurve CITriangleKaleidoscope CITwelvefoldReflectedTile CITwirlDistortion CIUnsharpMask CIVibrance CIVignette CIVortexDistortion CIWhitePointAdjust CIQRCodeGenerator

38 115 Built-in CIFilters on ios (7 Convolution) CIAccordianFoldTransition CIAdditionCompositing CIAffineClamp CIAffineTile CIAffineTransform CIAreaHistogram CIBarsSwipeTransition CIBlendWithMask CIBloom CIBumpDistortion CIBumpDistortionLinear CICheckerboardGenerator CICircleSplashDistortion CICircularScreen CICode128BarcodeGenerator CIColorBlendMode CIColorBurnBlendMode CIColorControls CIColorCube CIColorDodgeBlendMode CIColorInvert CIColorMap CIColorMatrix CIColorMonochrome CIColorClamp CIColorCrossPolynomial CIColorPolynomial CIColorPosterize CIConstantColorGenerator CIConvolution3X3 CIConvolution5X5 CIConvolution9Horizontal CIConvolution9Vertical CICopyMachineTransition CICrop CIDarkenBlendMode CIDifferenceBlendMode CIDisintegrateWithMask CIDissolveTransition CIDivideBlendMode CIDotScreen CIEightfoldReflectedTile CIExclusionBlendMode CIExposureAdjust CIFalseColor CIFlashTransition CIFourfoldReflectedTile CIFourfoldTranslatedTile CIGammaAdjust CIGaussianBlur CIGaussianGradient CIGlassDistortion CIGlideReflectedTile CIGloom CIHardLightBlendMode CIHatchedScreen CIHighlightShadowAdjust CIHistogramDisplayFilter CIHoleDistortion CIHueAdjust CIHueBlendMode CILanczosScaleTransform CILightenBlendMode CILightTunnel CILinearBurnBlendMode CILinearDodgeBlendMode CILinearGradient CILineScreen CILuminosityBlendMode CIMaskToAlpha CIMaximumComponent CIMaximumCompositing CIMinimumComponent CIMinimumCompositing CIModTransition CIMultiplyBlendMode CIMultiplyCompositing CIOverlayBlendMode CIPerspectiveCorrection CIPerspectiveTile CIPerspectiveTransform CIPinchDistortion CIPinLightBlendMode CIPixellate CIRadialGradient CIRandomGenerator CISaturationBlendMode CIScreenBlendMode CISepiaTone CISharpenLuminance CISixfoldReflectedTile CISixfoldRotatedTile CISoftLightBlendMode CISourceAtopCompositing CILinearToSRGBToneCurve CISRGBToneCurveToLinear CISourceInCompositing CISourceOutCompositing CISourceOverCompositing CIStarShineGenerator CIStraightenFilter CIStripesGenerator CISubtractBlendMode CISwipeTransition CITemperatureAndTint CIToneCurve CITriangleKaleidoscope CITwelvefoldReflectedTile CITwirlDistortion CIUnsharpMask CIVibrance CIVignette CIVortexDistortion CIWhitePointAdjust CIQRCodeGenerator

39 Anatomy of CIKernel OS X and ios CIKernel

40 Anatomy of CIKernel OS X and ios CIKernel ios Only

41 Anatomy of CIKernel OS X and ios CIKernel CIColorKernel CIWarpKernel ios Only

42 Anatomy of CIKernel + (CIKernel *) kernelwithstring:(nsstring *); - (CIImage *) applywithextent:(cgrect)extent roicallback:(cikernelroicallback)callback arguments:(nsarray Performs no actual work

43 Anatomy of CIKernel + (CIKernel *) kernelwithstring:(nsstring *); - (CIImage *) applywithextent:(cgrect)extent roicallback:(cikernelroicallback)callback arguments:(nsarray Performs no actual work GLSL + extensions for imaging Inputs and outputs are floats

44 Color Kernels CIColorKernel

45 Basic Principles of Color Kernels CIColorKernel Input Image(s) CIImage (RGBA8, ARGB8, RGBA Float, RGBA16, etc) CIColorKernel (everything is read as RGBA floats) Output Image CIImage (RGBA Float)

46 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; }

47 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; }

48 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; } kernel vec4 swapredandgreen ( sample s ) { return s.grba; }

49 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; } kernel vec4 swapredandgreen ( sample s ) { return s.grba; }

50 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; } kernel vec4 swapredandgreen ( sample s ) { return s.grba; }

51 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; } kernel vec4 swapredandgreen ( sample s ) { return s.grba; }

52 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; } kernel vec4 swapredandgreen ( sample s ) { return s.grba; } kernel vec4 swapredandgreenamount ( sample s, float amount ) { return mix(s.rgba, s.grba, amount); }

53 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; } kernel vec4 swapredandgreen ( sample s ) { return s.grba; } kernel vec4 swapredandgreenamount ( sample s, float amount ) { return mix(s.rgba, s.grba, amount); }

54 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; } kernel vec4 swapredandgreen ( sample s ) { return s.grba; } kernel vec4 swapredandgreenamount ( sample s, float amount ) { return mix(s.rgba, s.grba, amount); }

55 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; } kernel vec4 swapredandgreen ( sample s ) { return s.grba; } kernel vec4 swapredandgreenamount ( sample s, float amount ) { return mix(s.rgba, s.grba, amount); }

56 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; } kernel vec4 swapredandgreen ( sample s ) { return s.grba; } kernel vec4 swapredandgreenamount ( sample s, float amount ) { return mix(s.rgba, s.grba, amount); }

57 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; } kernel vec4 swapredandgreen ( sample s ) { return s.grba; } kernel vec4 swapredandgreenamount ( sample s, float amount ) { return mix(s.rgba, s.grba, amount); }

58 Color Kernel Example kernel vec4 donothing ( sample s ) { return s.rgba; } kernel vec4 swapredandgreen ( sample s ) { return s.grba; } kernel vec4 swapredandgreenamount ( sample s, float amount ) { return mix(s.rgba, s.grba, amount); }

59 Color Kernel Example Subclassing CIFilter

60 Color Kernel Example Subclassing SwapRedGreenFilter : (retain, nonatomic) CIImage (copy, nonatomic) NSNumber

61 Color Kernel Example Subclassing SwapRedGreenFilter : (retain, nonatomic) CIImage (copy, nonatomic) SwapRedGreenFilter -(CIKernel *)mykernel { } // convenience +(NSDictionary *)customattributes { } -(CIImage *)outputimage {

62 Color Kernel Example Applying the kernel inside of a CIFilter - (CIKernel *) mykernel { static CIColorKernel *kernel = nil; static dispatch_once_t once; dispatch_once(&once, ^{ kernel = [CIColorKernel kernel vec4 swapredandgreenamount ( sample s, float amount ) { return mix(s.rgba, s.grba, amount); } ]; }); return kernel; } - (CIImage *)outputimage { CGRect dod = inputimage.extent ; return [ [self mykernel] applywithextent : dod arguments inputamount]]; }

63 Color Kernel Example Applying the kernel inside of a CIFilter - (CIKernel *) mykernel { static CIColorKernel *kernel = nil; static dispatch_once_t once; dispatch_once(&once, ^{ kernel = [CIColorKernel kernel vec4 swapredandgreenamount ( sample s, float amount ) { return mix(s.rgba, s.grba, amount); } ]; }); return kernel; } - (CIImage *)outputimage { CGRect dod = inputimage.extent ; return [ [self mykernel] applywithextent : dod arguments inputamount]]; }

64 Color Kernel Example Applying the kernel inside of a CIFilter - (CIKernel *) mykernel { static CIColorKernel *kernel = nil; static dispatch_once_t once; dispatch_once(&once, ^{ kernel = [CIColorKernel kernel vec4 swapredandgreenamount ( sample s, float amount ) { return mix(s.rgba, s.grba, amount); } ]; }); return kernel; } - (CIImage *)outputimage { CGRect dod = inputimage.extent ; return [ [self mykernel] applywithextent : dod arguments inputamount]]; }

65 Color Kernel Example Applying the kernel inside of a CIFilter - (CIKernel *) mykernel { static CIColorKernel *kernel = nil; static dispatch_once_t once; dispatch_once(&once, ^{ kernel = [CIColorKernel kernel vec4 swapredandgreenamount ( sample s, float amount ) { return mix(s.rgba, s.grba, amount); } ]; }); return kernel; } - (CIImage *)outputimage { CGRect dod = inputimage.extent ; return [ [self mykernel] applywithextent : dod arguments inputamount]]; }

66 Color Kernel Example Applying the kernel inside of a CIFilter - (CIKernel *) mykernel { static CIColorKernel *kernel = nil; static dispatch_once_t once; dispatch_once(&once, ^{ kernel = [CIColorKernel kernel vec4 swapredandgreenamount ( sample s, float amount ) { return mix(s.rgba, s.grba, amount); } ]; }); return kernel; } - (CIImage *)outputimage { CGRect dod = inputimage.extent ; return [ [self mykernel] applywithextent : dod arguments inputamount]]; }

67 Color Kernel Which Depends on Position Vignette effect

68 Color Kernel Which Depends on Position Vignette effect

69 Color Kernel Which Depends on Position Vignette effect 1.0

70 Color Kernel Which Depends on Position Vignette effect

71 Color Kernel Which Depends on Position Vignette effect

72 Color Kernel Which Depends on Position Vignette effect

73 Color Kernel Which Depends on Position Vignette effect

74 Color Kernel Which Depends on Position Vignette effect

75 Color Kernel Which Depends on Position Vignette effect 0.0 x = 1.0

76 Color Kernel Which Depends on Position Vignette kernel code kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { }

77 Color Kernel Which Depends on Position Vignette kernel code kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { }

78 Color Kernel Which Depends on Position Vignette kernel code kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { } x extent.origin

79 Color Kernel Which Depends on Position Vignette kernel code kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { } x extent.origin

80 Color Kernel Which Depends on Position Vignette kernel code kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { } x extent.origin

81 Color Kernel Which Depends on Position Vignette kernel code kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { extent.size/ 2.0 } x extent.origin

82 Color Kernel Which Depends on Position Vignette kernel code kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { centeroffset extent.size/ 2.0 } x extent.origin

83 Color Kernel Which Depends on Position Vignette kernel code centeroffset = extent.origin + extent.size/2.0 kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { centeroffset }

84 Color Kernel Which Depends on Position Vignette kernel code centeroffset = extent.origin + extent.size/2.0 radius = length ( extent.size )/2.0 kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { centeroffset }

85 Color Kernel Which Depends on Position Vignette kernel code centeroffset = extent.origin + extent.size/2.0 radius = length ( extent.size )/2.0 kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { centeroffset }

86 Color Kernel Which Depends on Position Vignette kernel code centeroffset = extent.origin + extent.size/2.0 radius = length ( extent.size )/2.0 kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { centeroffset destcoord() }

87 Color Kernel Which Depends on Position Vignette kernel code centeroffset = extent.origin + extent.size/2.0 radius = length ( extent.size )/2.0 centeroffset destcoord() vecfromcenter kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { }

88 Color Kernel Which Depends on Position Vignette kernel code centeroffset = extent.origin + extent.size/2.0 radius = length ( extent.size )/2.0 vecfromcenter kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { centeroffset destcoord() vec2 vecfromcenter = destcoord () - centeroffset; }

89 Color Kernel Which Depends on Position Vignette kernel code centeroffset = extent.origin + extent.size/2.0 radius = length ( extent.size )/2.0 vecfromcenter kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { centeroffset destcoord() vec2 vecfromcenter = destcoord () - centeroffset; float distance = length ( vecfromcenter ) ; }

90 Color Kernel Which Depends on Position Vignette kernel code centeroffset = extent.origin + extent.size/2.0 radius = length ( extent.size )/2.0 vecfromcenter kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { centeroffset destcoord() vec2 vecfromcenter = destcoord () - centeroffset; float distance = length ( vecfromcenter ) ; float darken = ( distance / radius ) ; }

91 Color Kernel Which Depends on Position Vignette kernel code centeroffset = extent.origin + extent.size/2.0 radius = length ( extent.size )/2.0 vecfromcenter kernel vec4 vignette ( sample s, vec2 centeroffset, float radius ) { centeroffset destcoord() } vec2 vecfromcenter = destcoord () - centeroffset; float distance = length ( vecfromcenter ) ; float darken = ( distance / radius ) ; return vec4 ( s.rgb * darken, s.a ) ;

92 Color Kernel Which Depends on Position Vignette outputimage method - (CIImage *)outputimage { CGRect dod = inputimage.extent; double radius = 0.5 * hypot ( dod.size.width, dod.size.height ); CIVector *centeroffset = [CIVector vectorwithx : dod.size.width * dod.origin.x Y : dod.size.height * dod.origin.y]; return [[self mykernel] applywithextent : dod arguments }

93 Color Kernel Which Depends on Position Vignette outputimage method - (CIImage *)outputimage { CGRect dod = inputimage.extent; double radius = 0.5 * hypot ( dod.size.width, dod.size.height ); CIVector *centeroffset = [CIVector vectorwithx : dod.size.width * dod.origin.x Y : dod.size.height * dod.origin.y]; return [[self mykernel] applywithextent : dod arguments }

94 Color Kernel Which Depends on Position Vignette outputimage method - (CIImage *)outputimage { CGRect dod = inputimage.extent; double radius = 0.5 * hypot ( dod.size.width, dod.size.height ); CIVector *centeroffset = [CIVector vectorwithx : dod.size.width * dod.origin.x Y : dod.size.height * dod.origin.y]; return [[self mykernel] applywithextent : dod arguments }

95 Color Kernel Which Depends on Position Vignette outputimage method - (CIImage *)outputimage { CGRect dod = inputimage.extent; double radius = 0.5 * hypot ( dod.size.width, dod.size.height ); CIVector *centeroffset = [CIVector vectorwithx : dod.size.width * dod.origin.x Y : dod.size.height * dod.origin.y]; return [[self mykernel] applywithextent : dod arguments }

96 Color Kernel Which Depends on Position Vignette outputimage method - (CIImage *)outputimage { CGRect dod = inputimage.extent; double radius = 0.5 * hypot ( dod.size.width, dod.size.height ); CIVector *centeroffset = [CIVector vectorwithx : dod.size.width * dod.origin.x Y : dod.size.height * dod.origin.y]; return [[self mykernel] applywithextent : dod arguments }

97 Color Kernel Which Depends on Position Vignette outputimage method - (CIImage *)outputimage { CGRect dod = inputimage.extent; double radius = 0.5 * hypot ( dod.size.width, dod.size.height ); CIVector *centeroffset = [CIVector vectorwithx : dod.size.width * dod.origin.x Y : dod.size.height * dod.origin.y]; return [[self mykernel] applywithextent : dod arguments } kernel vec4 vignette ( sample s,vec2 centeroffset,float radius){ }

98 Color Kernel Which Depends on Position Vignette outputimage method - (CIImage *)outputimage { CGRect dod = inputimage.extent; double radius = 0.5 * hypot ( dod.size.width, dod.size.height ); CIVector *centeroffset = [CIVector vectorwithx : dod.size.width * dod.origin.x Y : dod.size.height * dod.origin.y]; return [[self mykernel] applywithextent : dod arguments } kernel vec4 vignette ( sample s,vec2 centeroffset,float radius){ }

99 Color Kernel Which Depends on Position Vignette outputimage method - (CIImage *)outputimage { CGRect dod = inputimage.extent; double radius = 0.5 * hypot ( dod.size.width, dod.size.height ); CIVector *centeroffset = [CIVector vectorwithx : dod.size.width * dod.origin.x Y : dod.size.height * dod.origin.y]; return [[self mykernel] applywithextent : dod arguments } kernel vec4 vignette ( sample s,vec2 centeroffset,float radius){ }

100 Color Kernel Which Depends on Position Vignette outputimage method - (CIImage *)outputimage { CGRect dod = inputimage.extent; double radius = 0.5 * hypot ( dod.size.width, dod.size.height ); CIVector *centeroffset = [CIVector vectorwithx : dod.size.width * dod.origin.x Y : dod.size.height * dod.origin.y]; return [[self mykernel] applywithextent : dod arguments } kernel vec4 vignette ( sample s,vec2 centeroffset,float radius){ }

101 DOD for Source over Compositing Kernel Non zero pixels kernel vec4 sourceover( sample src, sample dest ) { return src + (1.0-src.a)*dest; } CGRect dod = CGRectUnion ( inputimage.extent, inputbackgroundimage.extent )

102 DOD for Source over Compositing Kernel Non zero pixels kernel vec4 sourceover( sample src, sample dest ) { return src + (1.0-src.a)*dest; } CGRect dod = CGRectUnion ( inputimage.extent, inputbackgroundimage.extent )

103 Warp Kernels CIWarpKernel

104 Basic Principles of Warp Kernels CIWarpKernel Specify DOD and ROI block callback Input Position (vec2) CIWarpKernel Output Position (vec2)

105 Basic Principles of Warp Kernels CIWarpKernel think backwards kernel vec2 donothing () { return destcoord(); } y input image x

106 Basic Principles of Warp Kernels CIWarpKernel think backwards kernel vec2 donothing () { return destcoord(); } y input image y output image x x

107 Basic Principles of Warp Kernels CIWarpKernel think backwards kernel vec2 donothing () { return destcoord(); } y input image y output image destcoord() x x

108 Basic Principles of Warp Kernels CIWarpKernel think backwards kernel vec2 donothing () { return destcoord(); } y input image y output image destcoord() x x

109 Basic Principles of Warp Kernels CIWarpKernel think backwards kernel vec2 mirrorx ( float imagewidth ) { vec2 input = destcoord(); return vec2 ( imagewidth - input.x, input.y ); } y y x x

110 Basic Principles of Warp Kernels CIWarpKernel think backwards kernel vec2 mirrorx ( float imagewidth ) { vec2 input = destcoord(); return vec2 ( imagewidth - input.x, input.y ); } y y x x

111 Basic Principles of Warp Kernels CIWarpKernel think backwards kernel vec2 mirrorx ( float imagewidth ) { vec2 input = destcoord(); return vec2 ( imagewidth - input.x, input.y ); } y y destcoord() x x

112 Basic Principles of Warp Kernels CIWarpKernel think backwards kernel vec2 mirrorx ( float imagewidth ) { vec2 input = destcoord(); return vec2 ( imagewidth - input.x, input.y ); } y y destcoord() x x

113 Basic Principles of Warp Kernels CIWarpKernel think backwards kernel vec2 mirrorx ( float imagewidth ) { vec2 input = destcoord(); return vec2 ( imagewidth - input.x, input.y ); } y y destcoord() x x x

114 Basic Principles of Warp Kernels CIWarpKernel think backwards kernel vec2 mirrorx ( float imagewidth ) { vec2 input = destcoord(); return vec2 ( imagewidth - input.x, input.y ); } y y destcoord() x x x imagewidth

115 Basic Principles of Warp Kernels CIWarpKernel think backwards kernel vec2 mirrorx ( float imagewidth ) { vec2 input = destcoord(); return vec2 ( imagewidth - input.x, input.y ); } y y destcoord() x x x imagewidth imagewidth-x

116 Basic Principles of Warp Kernels CIWarpKernel think backwards kernel vec2 mirrorx ( float imagewidth ) { vec2 input = destcoord(); return vec2 ( imagewidth - input.x, input.y ); } y y destcoord() imagewidth-x x x imagewidth x imagewidth-x

117 Invoking MirrorX Kernel CIWarpKernel *kernel = [CIWarpKernel kernelwithstring:kernelsourcecode]; - (CIImage *) outputimage { CGFloat inputwidth = inputimage.extent.size.width; } CIImage *result = [[self mykernel] applywithextent: inputimage.extent roicallback: ^( int index, CGRect r ) { } inputimage: inputimage return result;

118 Invoking MirrorX Kernel CIWarpKernel *kernel = [CIWarpKernel kernelwithstring:kernelsourcecode]; - (CIImage *) outputimage { CGFloat inputwidth = inputimage.extent.size.width; } CIImage *result = [[self mykernel] applywithextent: inputimage.extent roicallback: ^( int index, CGRect r ) { } inputimage: inputimage return result;

119 Basic Principles of Warp Kernels For output rect, what part of input rect do we need ROI 5

120 Basic Principles of Warp Kernels For output rect, what part of input rect do we need ROI

121 Basic Principles of Warp Kernels For output rect, what part of input rect do we need ROI 5 5

122 Basic Principles of Warp Kernels For output rect, what part of input rect do we need ROI 5 5 CGRectMake (,,, );

123 Basic Principles of Warp Kernels For output rect, what part of input rect do we need ROI y y 5 5 x x CGRectMake (,,, );

124 Basic Principles of Warp Kernels For output rect, what part of input rect do we need ROI y y 5 5 x r.size.width x CGRectMake (,, r.size.width, );

125 Basic Principles of Warp Kernels For output rect, what part of input rect do we need ROI y y 5 5 r.size.height x r.size.width x CGRectMake (,, r.size.width, r.size.height);

126 Basic Principles of Warp Kernels For output rect, what part of input rect do we need ROI y y 5 5 r.size.height r.origin.y x r.size.width x CGRectMake (, r.origin.y, r.size.width, r.size.height);

127 Basic Principles of Warp Kernels For output rect, what part of input rect do we need ROI y y 5 5 r.size.height r.origin.y neworigin x r.size.width x CGRectMake ( neworigin, r.origin.y, r.size.width, r.size.height);

128 Basic Principles of Warp Kernels For output rect, what part of input rect do we need ROI y y 5 5 r.size.height r.origin.y neworigin x r.size.width x CGRectMake ( neworigin, r.origin.y, r.size.width, r.size.height); neworigin =

129 Basic Principles of Warp Kernels For output rect, what part of input rect do we need ROI y y 5 5 r.size.height r.origin.y neworigin x r.size.width x inputimage.extent.size.width CGRectMake ( neworigin, r.origin.y, r.size.width, r.size.height); neworigin = inputimage.extent.size.width

130 Basic Principles of Warp Kernels For output rect, what part of input rect do we need ROI y y 5 5 r.size.height r.origin.y neworigin x r.origin.x r.size.width x inputimage.extent.size.width CGRectMake ( neworigin, r.origin.y, r.size.width, r.size.height); neworigin = inputimage.extent.size.width - ( r.origin.x + r.size.width );

131 Invoking MirrorX Kernel - (CIImage *) outputimage { if ( CGRectIsInfinite ( inputimage.extent ) ) return nil; CGPoint o = inputimage.extent.origin; CGFloat inputwidth = inputimage.extent.size.width; CGAffineTransform to = CGAffineTransformMakeTranslation ( -o.x, -o.y ); CIImage *result = [inputimage imagebyapplyingtransform:to]; result = [[self mykernel] applywithextent: ]; // same as before CGAffineTransform from = CGAffineTransformMakeTranslation ( o.x, o.y ); } return [result imagebyapplyingtransform:from];

132 Invoking MirrorX Kernel - (CIImage *) outputimage { if ( CGRectIsInfinite ( inputimage.extent ) ) return nil; CGPoint o = inputimage.extent.origin; CGFloat inputwidth = inputimage.extent.size.width; CGAffineTransform to = CGAffineTransformMakeTranslation ( -o.x, -o.y ); CIImage *result = [inputimage imagebyapplyingtransform:to]; result = [[self mykernel] applywithextent: ]; // same as before CGAffineTransform from = CGAffineTransformMakeTranslation ( o.x, o.y ); } return [result imagebyapplyingtransform:from];

133 Invoking MirrorX Kernel - (CIImage *) outputimage { if ( CGRectIsInfinite ( inputimage.extent ) ) return nil; CGPoint o = inputimage.extent.origin; CGFloat inputwidth = inputimage.extent.size.width; CGAffineTransform to = CGAffineTransformMakeTranslation ( -o.x, -o.y ); CIImage *result = [inputimage imagebyapplyingtransform:to]; result = [[self mykernel] applywithextent: ]; // same as before CGAffineTransform from = CGAffineTransformMakeTranslation ( o.x, o.y ); } return [result imagebyapplyingtransform:from];

134 Invoking MirrorX Kernel - (CIImage *) outputimage { if ( CGRectIsInfinite ( inputimage.extent ) ) return nil; CGPoint o = inputimage.extent.origin; CGFloat inputwidth = inputimage.extent.size.width; CGAffineTransform to = CGAffineTransformMakeTranslation ( -o.x, -o.y ); CIImage *result = [inputimage imagebyapplyingtransform:to]; result = [[self mykernel] applywithextent: ]; // same as before CGAffineTransform from = CGAffineTransformMakeTranslation ( o.x, o.y ); } return [result imagebyapplyingtransform:from];

135 Invoking MirrorX Kernel - (CIImage *) outputimage { if ( CGRectIsInfinite ( inputimage.extent ) ) return nil; CGPoint o = inputimage.extent.origin; CGFloat inputwidth = inputimage.extent.size.width; CGAffineTransform to = CGAffineTransformMakeTranslation ( -o.x, -o.y ); CIImage *result = [inputimage imagebyapplyingtransform:to]; result = [[self mykernel] applywithextent: ]; // same as before CGAffineTransform from = CGAffineTransformMakeTranslation ( o.x, o.y ); } return [result imagebyapplyingtransform:from];

136 Invoking MirrorX Kernel - (CIImage *) outputimage { if ( CGRectIsInfinite ( inputimage.extent ) ) return nil; CGPoint o = inputimage.extent.origin; CGFloat inputwidth = inputimage.extent.size.width; CGAffineTransform to = CGAffineTransformMakeTranslation ( -o.x, -o.y ); CIImage *result = [inputimage imagebyapplyingtransform:to]; result = [[self mykernel] applywithextent: ]; // same as before CGAffineTransform from = CGAffineTransformMakeTranslation ( o.x, o.y ); } return [result imagebyapplyingtransform:from];

137 Invoking MirrorX Kernel - (CIImage *) outputimage { if ( CGRectIsInfinite ( inputimage.extent ) ) return nil; CGPoint o = inputimage.extent.origin; CGFloat inputwidth = inputimage.extent.size.width; CGAffineTransform to = CGAffineTransformMakeTranslation ( -o.x, -o.y ); CIImage *result = [inputimage imagebyapplyingtransform:to]; result = [[self mykernel] applywithextent: ]; // same as before CGAffineTransform from = CGAffineTransformMakeTranslation ( o.x, o.y ); } return [result imagebyapplyingtransform:from];

138 Invoking MirrorX Kernel - (CIImage *) outputimage { if ( CGRectIsInfinite ( inputimage.extent ) ) return nil; CGPoint o = inputimage.extent.origin; CGFloat inputwidth = inputimage.extent.size.width; CGAffineTransform to = CGAffineTransformMakeTranslation ( -o.x, -o.y ); CIImage *result = [inputimage imagebyapplyingtransform:to]; result = [[self mykernel] applywithextent: ]; // same as before CGAffineTransform from = CGAffineTransformMakeTranslation ( o.x, o.y ); } return [result imagebyapplyingtransform:from];

139 Invoking MirrorX Kernel - (CIImage *) outputimage { if ( CGRectIsInfinite ( inputimage.extent ) ) return nil; CGPoint o = inputimage.extent.origin; CGFloat inputwidth = inputimage.extent.size.width; CGAffineTransform to = CGAffineTransformMakeTranslation ( -o.x, -o.y ); CIImage *result = [inputimage imagebyapplyingtransform:to]; result = [[self mykernel] applywithextent: ]; // same as before CGAffineTransform from = CGAffineTransformMakeTranslation ( o.x, o.y ); } return [result imagebyapplyingtransform:from];

140 More Complex Warp Kernel Anamorphic stretch

141 More Complex Warp Kernel Anamorphic stretch 1024

142 More Complex Warp Kernel Anamorphic stretch

143 More Complex Warp Kernel Anamorphic stretch

144 More Complex Warp Kernel Anamorphic stretch

145 More Complex Warp Kernel Anamorphic stretch

146 sourcetodest() and desttosource() Invertible functions

147 sourcetodest() and desttosource() Invertible functions f(x) x

148 sourcetodest() and desttosource() Invertible functions f(x) - width/2 width/2 x

149 sourcetodest() and desttosource() Invertible functions f(x) scale = 1 - width/2 width/2 x

150 sourcetodest() and desttosource() Invertible functions f(x) scale = 1 f(xi)==xi - width/2 xi width/2 x

151 sourcetodest() and desttosource() Invertible functions f(x) scale = 1 f(xi)==xi - width/2 xi width/2 x

152 sourcetodest() and desttosource() Invertible functions f(x) scale = 1 f(xi)==xi - width/2 xi width/2 x

153 sourcetodest() and desttosource() Invertible functions f(x) scale = 1 - width/2 width/2 x DOD

154 sourcetodest() and desttosource() Invertible functions f(x) scale = 1 dest x - width/2 src x width/2 x DOD

155 sourcetodest() and desttosource() Invertible functions f(x) scale = 1 dest x src x dest x - width/2 src x width/2 x DOD Kernel and ROI

156 sourcetodest() and desttosource() Invertible functions scale = desiredwidth/inputwidth k = inputwidth/(1.0 - (1.0/scale))

157 sourcetodest() and desttosource() Invertible functions scale = desiredwidth/inputwidth k = inputwidth/(1.0 - (1.0/scale)) sourcetodest (1024) == 1280 desttosource (1280) == 1024

158 Kernel kernel vec2 strech (float center, float k) { vec2 p = destcoord(); return p; }

159 Kernel kernel vec2 strech (float center, float k) { vec2 p = destcoord(); return p; }

160 Kernel kernel vec2 strech (float center, float k) { vec2 p = destcoord(); p.x -= center; return p; }

161 Kernel kernel vec2 strech (float center, float k) { vec2 p = destcoord(); p.x -= center; p.x = p.x / (1.0 + abs(p.x / k)); p.x += center; return p; }

162 ROI Pseudocode r

163 ROI Pseudocode r r

164 ROI Pseudocode r r leftp = r.origin.x

165 ROI Pseudocode r r leftp = r.origin.x

166 ROI Pseudocode r r leftp = r.origin.x leftp = desttosource ( leftp )

167 ROI Pseudocode r r leftp = r.origin.x rightp = r.origin.x + r.size.width leftp = desttosource ( leftp )

168 ROI Pseudocode r r leftp = r.origin.x rightp = r.origin.x + r.size.width leftp = desttosource ( leftp )

169 ROI Pseudocode r r leftp = r.origin.x rightp = r.origin.x + r.size.width leftp = desttosource ( leftp ) rightp = desttosource ( rightp )

170 ROI Pseudocode r r leftp = r.origin.x rightp = r.origin.x + r.size.width leftp = desttosource ( leftp ) rightp = desttosource ( rightp ) newwidth = rightp - leftp r = CGRectMake ( leftp, r.origin.y, newwidth, r.size.height )

171 ROI Region of Interest Re-use kernel equation double desttosource(double x, double center, double k) { } return x;

172 ROI Region of Interest Re-use kernel equation double desttosource(double x, double center, double k) { } return x;

173 ROI Region of Interest Re-use kernel equation double desttosource(double x, double center, double k) { x -= center; x = x / (1.0 + fabs(x / k)); x += center; } return x;

174 ROI Region of Interest Re-use kernel equation double desttosource(double x, double center, double k) { x -= center; x = x / (1.0 + fabs(x / k)); x += center; } return x; CGRect regionof (CGRect r, float center, float k) { double leftp = desttosource (r.origin.x, center, k); double rightp = desttosource (r.origin.x + r.size.width, center, k); return CGRectMake (leftp, r.origin.y, rightp-leftp, r.size.height); }

175 DOD Domain of Definition double sourcetodest (double x, double center, double k) { x -= center; x = x / (1.0 - fabs(x / k)); x += center; } return x;

176 DOD Domain of Definition double sourcetodest (double x, double center, double k) { x -= center; x = x / (1.0 - fabs(x / k)); x += center; } return x; CGRect dodforinputrect (CGRect r, double center, double k) { double leftp = sourcetodest (r.origin.x, center, k); double rightp = sourcetodest (r.origin.x + r.size.width, center, k); return CGRectMake (leftp, r.origin.y, rightp-leftp, r.size.height); }

177 outputimage Method - (CIImage *) outputimage { double inputwidth = inputimage.extent.size.width; double k = inputwidth / ( / [inputscale floatvalue] ); double center = inputimage.extent.origin.x + inputwidth / 2.0; CGRect dod = dodforinputrect (inputimage.extent, center, k); } CIImage * result = [[self mykernel] applywithextent: dod roicallback: ^(int index, CGRect rect) { return regionof(rect, center, k); } inputimage: return result;

178 outputimage Method - (CIImage *) outputimage { double inputwidth = inputimage.extent.size.width; double k = inputwidth / ( / [inputscale floatvalue] ); double center = inputimage.extent.origin.x + inputwidth / 2.0; CGRect dod = dodforinputrect (inputimage.extent, center, k); } CIImage * result = [[self mykernel] applywithextent: dod roicallback: ^(int index, CGRect rect) { return regionof(rect, center, k); } inputimage: return result;

179 outputimage Method - (CIImage *) outputimage { double inputwidth = inputimage.extent.size.width; double k = inputwidth / ( / [inputscale floatvalue] ); double center = inputimage.extent.origin.x + inputwidth / 2.0; CGRect dod = dodforinputrect (inputimage.extent, center, k); } CIImage * result = [[self mykernel] applywithextent: dod roicallback: ^(int index, CGRect rect) { return regionof(rect, center, k); } inputimage: return result;

180 outputimage Method - (CIImage *) outputimage { double inputwidth = inputimage.extent.size.width; double k = inputwidth / ( / [inputscale floatvalue] ); double center = inputimage.extent.origin.x + inputwidth / 2.0; CGRect dod = dodforinputrect (inputimage.extent, center, k); } CIImage * result = [[self mykernel] applywithextent: dod roicallback: ^(int index, CGRect rect) { return regionof(rect, center, k); } inputimage: return result;

181 outputimage Method - (CIImage *) outputimage { double inputwidth = inputimage.extent.size.width; double k = inputwidth / ( / [inputscale floatvalue] ); double center = inputimage.extent.origin.x + inputwidth / 2.0; CGRect dod = dodforinputrect (inputimage.extent, center, k); } CIImage * result = [[self mykernel] applywithextent: dod roicallback: ^(int index, CGRect rect) { return regionof(rect, center, k); } inputimage: return result;

182 customattributes Method + (NSDictionary *)customattributes { kciattributefilterdisplayname Anamorphic Stretch", kciattributefiltercategories : kcicategoryvideo, kcicategoryinterlaced, kcicategorynonsquarepixels, kciattributeslidermin kciattributeslidermax kciattributedefault kciattributeidentity kciattributetype : kciattributetypescalar } };

183 customattributes Method + (NSDictionary *)customattributes { kciattributefilterdisplayname Anamorphic Stretch", kciattributefiltercategories : kcicategoryvideo, kcicategoryinterlaced, kcicategorynonsquarepixels, kciattributeslidermin kciattributeslidermax kciattributedefault kciattributeidentity kciattributetype : kciattributetypescalar } };

184 customattributes Method + (NSDictionary *)customattributes { kciattributefilterdisplayname Anamorphic Stretch", kciattributefiltercategories : kcicategoryvideo, kcicategoryinterlaced, kcicategorynonsquarepixels, kciattributeslidermin kciattributeslidermax kciattributedefault kciattributeidentity kciattributetype : kciattributetypescalar } };

185 customattributes Method + (NSDictionary *)customattributes { kciattributefilterdisplayname Anamorphic Stretch", kciattributefiltercategories : kcicategoryvideo, kcicategoryinterlaced, kcicategorynonsquarepixels, kciattributeslidermin kciattributeslidermax kciattributedefault kciattributeidentity kciattributetype : kciattributetypescalar } };

186 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

187 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

188 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

189 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

190 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

191 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

192 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

193 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

194 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

195 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

196 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

197 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

198 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

199 CIKernel Wrap-Up # Input Images Input Type Access Output Image DOD ROI ClColorKernel 0.. n sample vec4 vec4 YES NO ClWarpKernel 1 destcoord() vec2 vec2 YES YES ClKernel 0.. n sampler sample( ) vec4 YES YES

200 General Kernels CIKernel Tony Chu

201 Different Types of Kernels Color Kernels (CIColorKernel) Warp Kernels (CIWarpKernel) General Kernels (CIKernel)

202 Motivation CIKernel When would you need to write a general kernel?

203 Motivation CIKernel When would you need to write a general kernel? Kernel needs multiple samples of an image

204 Motivation CIKernel When would you need to write a general kernel? Kernel needs multiple samples of an image - e.g., any kind of blur or convolution filter

205 Motivation CIKernel When would you need to write a general kernel? Kernel needs multiple samples of an image - e.g., any kind of blur or convolution filter Kernel contains a dependent texture read

206 Motivation CIKernel When would you need to write a general kernel? Kernel needs multiple samples of an image - e.g., any kind of blur or convolution filter Kernel contains a dependent texture read - e.g., sample from image A used to determine where to sample from image B

207 Basic Principles of General Kernels CIKernel Input Input Image(s) Input Image(s) Output Image Sampler CIKernel CIImage

208 Basic Principles of General Kernels CIKernel Input Input Image(s) Input Image(s) Output Image Sampler CIKernel CIImage

209 Basic Principles of General Kernels kernel vec4 do_nothing (sampler image) { vec2 dc = destcoord(); return sample (image, samplertransform (image, dc)); }

210 Basic Principles of General Kernels kernel vec4 do_nothing (sampler image) { vec2 dc = destcoord(); return sample (image, samplertransform (image, dc)); } kernel vec4 do_nothing (sampler image) { return sample (image, samplercoord (image)); }

211 Basic Principles of General Kernels kernel vec4 do_nothing (sampler image) { vec2 dc = destcoord(); return sample (image, samplertransform (image, dc)); } = kernel vec4 do_nothing (sampler image) { return sample (image, samplercoord (image)); }

212 Basic Principles of General Kernels kernel vec4 do_nothing (sampler image) { vec2 dc = destcoord(); return sample (image, samplertransform (image, dc)); } = kernel vec4 do_nothing (sampler image) { return sample (image, samplercoord (image)); } Why use samplertransform?

213 Basic Principles of General Kernels Destination space vs. Sampler space kernel vec4 do_something (sampler image) { vec2 sc = samplercoord (image); vec2 offset = vec2(0.0, 2.0); return sample (image, sc + offset); }

214 Basic Principles of General Kernels Destination space vs. Sampler space kernel vec4 do_something (sampler image) { vec2 sc = samplercoord (image); vec2 offset = vec2(0.0, 2.0); return sample (image, sc + offset); } y Destination space x

215 Basic Principles of General Kernels Destination space vs. Sampler space kernel vec4 do_something (sampler image) { vec2 sc = samplercoord (image); vec2 offset = vec2(0.0, 2.0); return sample (image, sc + offset); } y y Destination space Sampler space x x

216 Basic Principles of General Kernels Destination space vs. Sampler space kernel vec4 do_something (sampler image) { vec2 sc = samplercoord (image); vec2 offset = vec2(0.0, 2.0); return sample (image, sc + offset); } y y Destination space Sampler space (300, 200) x x

217 Basic Principles of General Kernels Destination space vs. Sampler space kernel vec4 do_something (sampler image) { vec2 sc = samplercoord (image); vec2 offset = vec2(0.0, 2.0); return sample (image, sc + offset); } y y Destination space Sampler space (300, 200) (0.5, 0.5) x x

218 Basic Principles of General Kernels Destination space vs. Sampler space kernel vec4 do_something (sampler image) { vec2 sc = samplercoord (image); vec2 offset = vec2(0.0, 2.0); return sample (image, sc + offset); } y y (0.5, 2.5) Destination space Sampler space (300, 200) (0.5, 0.5) x x

219 Basic Principles of General Kernels Destination space vs. Sampler space kernel vec4 do_something (sampler image) { vec2 sc = samplercoord (image); vec2 offset = vec2(0.0, 2.0); return sample (image, sc + offset); } y y (0.5, 2.5) Destination space Sampler space (300, 200) (0.5, 0.5) x x

220 Basic Principles of General Kernels Destination space vs. Sampler space kernel vec4 do_something (sampler image) { vec2 dc = destcoord(); vec2 offset = vec2(0.0, 2.0); return sample (image, samplertransform (image, dc + offset)); } y y Destination space Sampler space x x

221 Basic Principles of General Kernels Destination space vs. Sampler space kernel vec4 do_something (sampler image) { vec2 dc = destcoord(); vec2 offset = vec2(0.0, 2.0); return sample (image, samplertransform (image, dc + offset)); } y y Destination space Sampler space (300, 200) x x

222 Basic Principles of General Kernels Destination space vs. Sampler space kernel vec4 do_something (sampler image) { vec2 dc = destcoord(); vec2 offset = vec2(0.0, 2.0); return sample (image, samplertransform (image, dc + offset)); } y y Destination space Sampler space 400 (300, 202) 1 (300, 200) x x

223 Basic Principles of General Kernels Destination space vs. Sampler space kernel vec4 do_something (sampler image) { vec2 dc = destcoord(); vec2 offset = vec2(0.0, 2.0); return sample (image, samplertransform (image, dc + offset)); } y y Destination space Sampler space 400 (300, 202) 1 (300, 200) (0.5, 0.505) x x

224 Basic Principles of General Kernels Destination space vs. Sampler space kernel vec4 do_something (sampler image) { vec2 dc = destcoord(); vec2 offset = vec2(0.0, 2.0); return sample (image, samplertransform (image, dc + offset)); } y y Destination space Sampler space 400 (300, 202) 1 (300, 200) (0.5, 0.505) x x

225 Examples CIKernel

226 Motion Blur Kernel requires multiple samples

227 Motion Blur Kernel requires multiple samples Compute the average of N samples along a bi-directional vector

228 Motion Blur Kernel requires multiple samples Compute the average of N samples along a bi-directional vector

229 Motion Blur Kernel requires multiple samples Compute the average of N samples along a bi-directional vector

230 Motion Blur CIKernel kernel vec4 motionblur (sampler image, vec2 velocity) { const int NUM_SAMPLES = 10; // per direction vec4 s = vec4(0.0); vec2 dc = destcoord(), offset = -velocity; for (int i=0; i < (NUM_SAMPLES * 2 + 1); i++) { s += sample (image, samplertransform (image, dc + offset)); offset += velocity / float(num_samples); } } return s / float((num_samples * 2 + 1));

231 Motion Blur CIKernel kernel vec4 motionblur (sampler image, vec2 velocity) { const int NUM_SAMPLES = 10; // per direction vec4 s = vec4(0.0); vec2 dc = destcoord(), offset = -velocity; for (int i=0; i < (NUM_SAMPLES * 2 + 1); i++) { s += sample (image, samplertransform (image, dc + offset)); offset += velocity / float(num_samples); } } return s / float((num_samples * 2 + 1));

232 Motion Blur CIKernel kernel vec4 motionblur (sampler image, vec2 velocity) { const int NUM_SAMPLES = 10; // per direction vec4 s = vec4(0.0); vec2 dc = destcoord(), offset = -velocity; for (int i=0; i < (NUM_SAMPLES * 2 + 1); i++) { s += sample (image, samplertransform (image, dc + offset)); offset += velocity / float(num_samples); } } return s / float((num_samples * 2 + 1));

233 Motion Blur CIKernel kernel vec4 motionblur (sampler image, vec2 velocity) { const int NUM_SAMPLES = 10; // per direction vec4 s = vec4(0.0); vec2 dc = destcoord(), offset = -velocity; for (int i=0; i < (NUM_SAMPLES * 2 + 1); i++) { s += sample (image, samplertransform (image, dc + offset)); offset += velocity / float(num_samples); } } return s / float((num_samples * 2 + 1));

234 Motion Blur CIKernel kernel vec4 motionblur (sampler image, vec2 velocity) { const int NUM_SAMPLES = 10; // per direction vec4 s = vec4(0.0); vec2 dc = destcoord(), offset = -velocity; for (int i=0; i < (NUM_SAMPLES * 2 + 1); i++) { s += sample (image, samplertransform (image, dc + offset)); offset += velocity / float(num_samples); } } return s / float((num_samples * 2 + 1));

235 Motion Blur CIKernel kernel vec4 motionblur (sampler image, vec2 velocity) { const int NUM_SAMPLES = 10; // per direction vec4 s = vec4(0.0); vec2 dc = destcoord(), offset = -velocity; for (int i=0; i < (NUM_SAMPLES * 2 + 1); i++) { s += sample (image, samplertransform (image, dc + offset)); offset += velocity / float(num_samples); } } return s / float((num_samples * 2 + 1));

236 Motion Blur CIFilter subclass - (CIKernel *)mykernel { static CIKernel *kernel = [CIKernel kernelwithstring:source]; return kernel; } - (CIImage *)outputimage { float r = inputradius.floatvalue, a = inputangle.floatvalue; CIVector *velocity = [CIVector vectorwithx:r*cos(a) Y:r*sin(a)]; } return [[self mykernel] applywithextent:dod roicallback:^(int index, CGRect rect) { return regionof(rect,velocity); } velocity] ];

237 Motion Blur CIFilter subclass - (CIKernel *)mykernel { static CIKernel *kernel = [CIKernel kernelwithstring:source]; return kernel; } - (CIImage *)outputimage { float r = inputradius.floatvalue, a = inputangle.floatvalue; CIVector *velocity = [CIVector vectorwithx:r*cos(a) Y:r*sin(a)]; } return [[self mykernel] applywithextent:dod roicallback:^(int index, CGRect rect) { return regionof(rect,velocity); } velocity] ];

238 Motion Blur CIFilter subclass - (CIKernel *)mykernel { kernel vec4 motionblur (sampler image, vec2 velocity) { const int NUM_SAMPLES = 10; // per direction vec4 s = vec4(0.0); vec2 dc = destcoord(), offset = -velocity; for (int i=0; i < (NUM_SAMPLES * 2 + 1); i++) { s += sample (image, samplertransform (image, dc + offset)); offset += velocity / float(num_samples); } return s / float((num_samples * 2 + 1)); } static CIKernel *kernel = [CIKernel kernelwithstring:source]; return kernel; } - (CIImage *)outputimage { float r = inputradius.floatvalue, a = inputangle.floatvalue; CIVector *velocity = [CIVector vectorwithx:r*cos(a) Y:r*sin(a)]; return [[self mykernel] applywithextent:dod roicallback:^(int index, CGRect rect) { return regionof(rect,velocity); } velocity] ]; }

239 Motion Blur CIFilter subclass - (CIKernel *)mykernel { static CIKernel *kernel = [CIKernel kernelwithstring:source]; return kernel; } - (CIImage *)outputimage { float r = inputradius.floatvalue, a = inputangle.floatvalue; CIVector *velocity = [CIVector vectorwithx:r*cos(a) Y:r*sin(a)]; } return [[self mykernel] applywithextent:dod roicallback:^(int index, CGRect rect) { return regionof(rect,velocity); } velocity] ];

240 Motion Blur CIFilter subclass - (CIKernel *)mykernel { static CIKernel *kernel = [CIKernel kernelwithstring:source]; return kernel; } - (CIImage *)outputimage { float r = inputradius.floatvalue, a = inputangle.floatvalue; CIVector *velocity = [CIVector vectorwithx:r*cos(a) Y:r*sin(a)]; } return [[self mykernel] applywithextent:dod roicallback:^(int index, CGRect rect) { return regionof(rect,velocity); } velocity] ];

241 Motion Blur CIFilter subclass - (CIKernel *)mykernel { static CIKernel *kernel = [CIKernel kernelwithstring:source]; return kernel; } - (CIImage *)outputimage { float r = inputradius.floatvalue, a = inputangle.floatvalue; CIVector *velocity = [CIVector vectorwithx:r*cos(a) Y:r*sin(a)]; } return [[self mykernel] applywithextent:dod roicallback:^(int index, CGRect rect) { return regionof(rect,velocity); } velocity] ];

242 Motion Blur DOD extent.size.height extent.origin extent.size.width

243 Motion Blur DOD extent.size.height extent.origin extent.size.width

244 Motion Blur DOD extent.size.height extent.origin extent.size.width

245 Motion Blur DOD extent.size.height extent.origin extent.size.width

246 Motion Blur DOD extent.size.height extent.origin extent.size.width velocity.x

247 Motion Blur DOD extent.size.height extent.origin extent.size.width velocity.x DOD = CGRectInset (inputimage.extent, -abs(velocity.x), -abs(velocity.y));

248 Motion Blur ROI

249 Motion Blur ROI

250 Motion Blur ROI

251 Motion Blur ROI

252 Motion Blur ROI

253 Motion Blur ROI

254 Motion Blur ROI

255 Motion Blur ROI

256 Motion Blur ROI CGRect regionof (CGRect rect, CIVector *velocity) { return CGRectInset (rect, -abs(velocity.x), -abs(velocity.y)); }

257 Motion Blur 2.0

258 Motion Blur 2.0

259 Motion Blur 2.0

260 Motion Blur with Masked Vector Field Kernel contains dependent texture read

261 Motion Blur with Masked Vector Field Kernel contains dependent texture read

262 Motion Blur with Masked Vector Field Kernel contains dependent texture read

263 Motion Blur with Masked Vector Field Kernel contains dependent texture read CIKernel

264 Motion Blur with Masked Vector Field Kernel contains dependent texture read CIKernel

265 Motion Blur with Masked Vector Field Kernel contains dependent texture read CIKernel

266 Motion Blur with Masked Vector Field Kernel contains dependent texture read CIKernel

267 Motion Blur with Masked Vector Field CIKernel

268 Motion Blur with Masked Vector Field CIKernel

269 Motion Blur with Masked Vector Field CIKernel kernel vec4 motionblurwithmask (sampler image, sampler mask, float radius) { // read per-pixel directional vector from mask image first vec2 dir = sample (mask, samplercoord(mask)).rg; dir = dir * ; // de-normalize vector from [0,1] to [-1,+1] vec2 velocity = dir * radius; } return _motionblur (image, velocity);

270 Motion Blur with Masked Vector Field CIKernel vec4 _motionblur (sampler image, vec2 velocity) { } kernel vec4 motionblurwithmask (sampler image, sampler mask, float radius) { // read per-pixel directional vector from mask image first vec2 dir = sample (mask, samplercoord(mask)).rg; dir = dir * ; // de-normalize vector from [0,1] to [-1,+1] // apply regular motion blur effect vec2 velocity = dir * radius; } return _motionblur (image, velocity);

271 Motion Blur with Masked Vector Field CIKernel vec4 _motionblur (sampler image, vec2 velocity) { } kernel vec4 motionblurwithmask (sampler image, sampler mask, float radius) { // read per-pixel directional vector from mask image first vec2 dir = sample (mask, samplercoord(mask)).rg; dir = dir * ; // de-normalize vector from [0,1] to [-1,+1] // apply regular motion blur effect vec2 velocity = dir * radius; } return _motionblur (image, velocity);

272 Motion Blur with Masked Vector Field CIKernel vec4 _motionblur (sampler image, vec2 velocity) { } kernel vec4 motionblurwithmask (sampler image, sampler mask, float radius) { // read per-pixel directional vector from mask image first vec2 dir = sample (mask, samplercoord(mask)).rg; dir = dir * ; // de-normalize vector from [0,1] to [-1,+1] // apply regular motion blur effect vec2 velocity = dir * radius; } return _motionblur (image, velocity);

273 Motion Blur with Masked Vector Field CIKernel vec4 _motionblur (sampler image, vec2 velocity) { } kernel vec4 motionblurwithmask (sampler image, sampler mask, float radius) { // read per-pixel directional vector from mask image first vec2 dir = sample (mask, samplercoord(mask)).rg; dir = dir * ; // de-normalize vector from [0,1] to [-1,+1] // apply regular motion blur effect vec2 velocity = dir * radius; } return _motionblur (image, velocity);

274 Motion Blur with Masked Vector Field CIFilter subclass - (CIImage *)outputimage { float r = inputradius.floatvalue; CGRect DOD = CGRectInset (inputimage.extent, -r, -r); } return [[self mykernel] applywithextent:dod roicallback:^(int index, CGRect rect) { return regionof (index, rect, r); } maskimage, inputradius] ];

275 Motion Blur with Masked Vector Field CIFilter subclass - (CIImage *)outputimage { float r = inputradius.floatvalue; CGRect DOD = CGRectInset (inputimage.extent, -r, -r); } return [[self mykernel] applywithextent:dod roicallback:^(int index, CGRect rect) { return regionof (index, rect, r); } maskimage, inputradius] ];

276 Motion Blur with Masked Vector Field CIFilter subclass - (CIImage *)outputimage { float r = inputradius.floatvalue; CGRect DOD = CGRectInset (inputimage.extent, -r, -r); } return [[self mykernel] applywithextent:dod roicallback:^(int index, CGRect rect) { return regionof (index, rect, r); } maskimage, inputradius] ];

277 Motion Blur with Masked Vector Field ROI for multiple images CGRect regionof (int index, CGRect rect, float radius) { if (index == 0) { return CGRectInset (rect, -radius, -radius); // ROI for input image } else if (index == 1) { return rect; // ROI for mask image } } return CGRectNull; // should not reach here

278 Motion Blur with Masked Vector Field ROI for multiple images CGRect regionof (int index, CGRect rect, float radius) { if (index == 0) { return CGRectInset (rect, -radius, -radius); // ROI for input image } else if (index == 1) { return rect; // ROI for mask image } } return CGRectNull; // should not reach here

279 Motion Blur with Masked Vector Field ROI for multiple images CGRect regionof (int index, CGRect rect, float radius) { if (index == 0) { return CGRectInset (rect, -radius, -radius); // ROI for input image } else if (index == 1) { return rect; // ROI for mask image } } return CGRectNull; // should not reach here

280 Portability of General Kernels OS X and ios Desktop-class kernel type with the same language syntax and semantics as OS X

281 Portability of General Kernels OS X and ios Desktop-class kernel type with the same language syntax and semantics as OS X New built-in filters on ios ported from OS X using general kernels

282 Portability of General Kernels OS X and ios Desktop-class kernel type with the same language syntax and semantics as OS X New built-in filters on ios ported from OS X using general kernels Glass Distortion

283 Portability of General Kernels OS X and ios Desktop-class kernel type with the same language syntax and semantics as OS X New built-in filters on ios ported from OS X using general kernels Glass Distortion Histogram Display

284 Performance Considerations Multiple render passes Input Input Image(s) Input Image(s) Output Image Sampler CIKernel CIImage

285 Performance Considerations Multiple render passes Input Input Image(s) Input Image(s) Output Image Sampler CIKernel CIImage

286 Performance Considerations Multiple render passes Input Input Image(s) Input Image(s) Output Image Sampler CIKernel CIImage Each input image to a CIKernel adds an extra render pass

287 Intermediate Buffers kcicontextworkingformat 8-bit kciformatrgba8 16-bit kciformatrgbah Null Working Space (Color Management Off) Default Working Space (Linear Rec. 709) Needs Linear to srgb Needs 2X Memory

288 Intermediate Buffers kcicontextworkingformat 8-bit kciformatrgba8 16-bit kciformatrgbah Null Working Space (Color Management Off) Default Working Space (Linear Rec. 709) Needs Linear to srgb Needs 2X Memory

289 Intermediate Buffers kcicontextworkingformat 8-bit kciformatrgba8 16-bit kciformatrgbah Null Working Space (Color Management Off) Default Working Space (Linear Rec. 709) Needs Linear to srgb Needs 2X Memory

290 Intermediate Buffers kcicontextworkingformat 8-bit kciformatrgba8 16-bit kciformatrgbah Null Working Space (Color Management Off) Default Working Space (Linear Rec. 709) Needs Linear to srgb Needs 2X Memory

291 Square Kaleidoscope CIKernel?

292 Square Kaleidoscope CIKernel?

293 Square Kaleidoscope CIKernel? CIFilter? = CIKernel

294 Square Kaleidoscope CIKernel? CIFilter? = CIKernel

295 Square Kaleidoscope Better solution CIFilter? =

296 Square Kaleidoscope Better solution CIFilter? =

297 Square Kaleidoscope Better solution CIFilter CIWarpKernel? =

298 Square Kaleidoscope Better solution CIFilter CIWarpKernel? =

299 Square Kaleidoscope Better solution CIFilter CIWarpKernel? = + CIColorKernel

300 Square Kaleidoscope Better solution CIFilter CIWarpKernel? = + CIColorKernel

301 Square Kaleidoscope CIWarpKernel kernel vec2 squarekaleidoscopewarp (vec2 center, float size) { // offset by center and transform to unit square vec2 p = (destcoord() - center) / size; // calculate number of mirror reflections to get to this point float z = abs(floor(p.x)) + abs(floor(p.y)); // reflect this point into unit square space p = abs(mod(p, 2.0) - 1.0); } // transform back to destination space return (p * size) + center;

302 Square Kaleidoscope CIColorKernel kernel vec4 squarekaleidoscopecolor ( sample s, vec2 center, float size) { // offset by center and transform to unit square vec2 p = (destcoord() - center) / size; // calculate number of mirror reflections to get to this point float z = abs(floor(p.x)) + abs(floor(p.y)); // exponential decay float k = pow(0.8, z); } // multiply color sample with decay return vec4(s.rgb * k, s.a);

303 Square Kaleidoscope CIWarpKernel and CIColorKernel CIImage *warpedimage = [warpkernel applywithextent:cgrectinfinite roicallback:^(int index, CGRect rect) { return corerect; } inputimage:inputimage size] ];

304 Square Kaleidoscope CIWarpKernel and CIColorKernel CIWarpKernel CIImage *warpedimage = [warpkernel applywithextent:cgrectinfinite roicallback:^(int index, CGRect rect) { return corerect; } inputimage:inputimage size] ];

305 Square Kaleidoscope CIWarpKernel and CIColorKernel CIWarpKernel CIImage *warpedimage = [warpkernel applywithextent:cgrectinfinite roicallback:^(int index, CGRect rect) { return corerect; } inputimage:inputimage size] ];

306 Square Kaleidoscope CIWarpKernel and CIColorKernel CIWarpKernel CIImage *warpedimage = [warpkernel applywithextent:cgrectinfinite roicallback:^(int index, CGRect rect) { return corerect; } inputimage:inputimage size] ];

307 Square Kaleidoscope CIWarpKernel and CIColorKernel CIWarpKernel CIImage *warpedimage = [warpkernel applywithextent:cgrectinfinite roicallback:^(int index, CGRect rect) { return corerect; } inputimage:inputimage size] ];

308 Square Kaleidoscope CIWarpKernel and CIColorKernel CIWarpKernel CIImage *warpedimage = [warpkernel applywithextent:cgrectinfinite roicallback:^(int index, CGRect rect) { return corerect; } inputimage:inputimage size] ]; CIImage *outputimage = [colorkernel applywithextent:warpedimage.extent center, size] ];

309 Square Kaleidoscope CIWarpKernel and CIColorKernel CIWarpKernel CIColorKernel CIImage *warpedimage = [warpkernel applywithextent:cgrectinfinite roicallback:^(int index, CGRect rect) { return corerect; } inputimage:inputimage size] ]; CIImage *outputimage = [colorkernel applywithextent:warpedimage.extent center, size] ];

310 Square Kaleidoscope CIWarpKernel and CIColorKernel CIWarpKernel CIColorKernel CIImage *warpedimage = [warpkernel applywithextent:cgrectinfinite roicallback:^(int index, CGRect rect) { return corerect; } inputimage:inputimage size] ]; CIImage *outputimage = [colorkernel applywithextent:warpedimage.extent center, size] ];

311 Recommendations

312 Recommendations Write a general kernel only when needed

313 Recommendations Write a general kernel only when needed Write a general kernel initially for rapid prototyping, then try replacing with some combination of warp and color kernels

314 Platform Differences

315 Platform Differences ios OS X Renderers GPU CPU and GPU Control flow in language Yes No Kernel classes CIKernel CIColorKernel CIWarpKernel CIKernel CISampler No Yes DOD CGRect CIFilterShape ROI Block Pointer Selector [CIFilter setdefaults] Automatic Explicit [CIFilter customattributes] Class Method Instance Method

316 What You ve Learned Today

317 What You ve Learned Today How to write Color, Warp, and general kernels

318 What You ve Learned Today How to write Color, Warp, and general kernels DOD and ROI

319 What You ve Learned Today How to write Color, Warp, and general kernels DOD and ROI ROI function is critical for large image support to work correctly and optimally

320 What You ve Learned Today How to write Color, Warp, and general kernels DOD and ROI ROI function is critical for large image support to work correctly and optimally Platform differences

321 More Information Allan Schaffer Graphics and Game Technologies Evangelist Developer Technical Support Apple Developer Forums

322 Related Sessions Introducing the Photos Frameworks Nob Hill Thursday 10:15AM Advances in Core Image Pacific Heights Thursday 2:00PM

323 Labs Core Image Lab Media Lab B Thursday 4:30PM

324