A set of filters and utilities for Apple's Core Image framework.

Available on both OS X and iOS.

Involving...

Core Image Filters

Filters

YUCIRGBToneCurve

Adjusts tone response of the R, G, and B channels of an image.

The filter takes in an array of control points that define the spline curve for each color component, or for all three in the composite.

These are stored as

CIVector

NSArray

0

1

The defaults are

[(0,0), (0.5,0.5), (1,1)]

YUCIColorLookup

Uses a color lookup table (LUT) to remap the colors in an image. The default LUT can be found at

Sources/YUCIColorLookupTableDefault.png

This filter may not work well in the default light-linear working color space. Use

kCIContextWorkingColorSpace

CIContext

YUCISurfaceBlur

A bilateral filter. Blurs an image while preserving edges. This filter is almost identical to Photoshop's "Surface Blur" filter.

Useful for creating special effects and for removing noise or graininess. Slow on large

inputRadius

YUCITriangularPixellate

Maps an image to colored triangles.

YUCIFXAA

A basic implementation of FXAA (Fast Approximate Anti-Aliasing).

YUCIHistogramEqualization

Perform a Histogram Equalization on the input image. Internally uses

Accelerate.framework

YUCIReflectedTile

Produces a tiled image from a source image by reflecting pixels over the edges.

YUCICLAHE

Perform a Contrast Limited Adaptive Histogram Equalization on the lightness channel of the input image.

Transitions

YUCICrossZoomTransition

A transition that pushes the

inputImage

inputTargetImage

YUCIFlashTransition

Transitions from one image to another by creating a flash effect.

Generators

YUCIStarfieldGenerator

Generate a starfield image. Animatable by changing the

inputTime

YUCIBlobsGenerator

Generate a image with colorful blobs. Animatable by changing the

inputTime

Utilities

YUCIFilterConstructor

A singleton that conforms to

CIFilterConstructor

Can be used in

+[CIFilter registerFilterName:constructor:classAttributes:]

CIFilter

filterName

CIFilter

[[FilterClass alloc] init]

YUCIFilterPreviewGenerator

Can be used to generate a preview image/gif for a filter. All the preview images/gifs on this page are generated by this utility. For demonstration/testing purposes only, do not use it in your production code.

Next

• [x] Add filter previews to readme.
• [x] AA for triangular pixellate filter.
• [x] CLAHE
• [ ] Write a paper on the implementation of CLAHE.
• [ ] Kuwahara filter

Related Projects

YUCIHighPassSkinSmoothing

An implementation of High Pass Skin Smoothing.

YUCIImageView

An image view for rendering CIImage with Metal/OpenGL/CoreGraphics.

MetalPetal

A image processing framework based on Metal.