相关疑难解决方法(0)

如何使用OpenGL ES 2.0着色器执行以下图像处理任务？

• 色彩空间变换(RGB/YUV/HSL/Lab)
• 旋转的图像
• 转换为草图
• 转换成油画

根据文档,它应该支持模糊,请注意"在iOS 5.0及更高版本中可用":

CIFilter类参考

但根据该设备,它不会:

[CIFilter filterNamesInCategory:kCICategoryBlur];

没有回报.

根据以下内容,我的iPhone和模拟器上只有这些过滤器可用(它们都运行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

我想知道将照片转换成铅笔画的步骤是什么.人们通常建议:

1. 反转图像(使负面)
2. 应用高斯模糊
3. 通过线性闪避或颜色闪避来混合上面的图像.

请参见此处:将图像转换为铅笔草图

还有其他方法吗？我特别感兴趣的是强调铅笔笔触的方法,比如iPhone App:Snap和Sketch

对于如何开始的任何建议,我将非常感激.