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# init(source:)

Creates a single kernel object.

```
convenience init?(source string: String)
```

## Parameters

`string`

A program in the Core Image Kernel Language that contains a single routine marked using the `kernel` keyword.

## Return Value

A new kernel object. The class of the returned object can be [`CIKernel`](/documentation/CoreImage/CIKernel), [`CIColorKernel`](/documentation/CoreImage/CIColorKernel), or [`CIWarpKernel`](/documentation/CoreImage/CIWarpKernel) depending on the type of routine specified in the Core Image Kernel Language source code string.

## Discussion

The Core Image Kernel Language is a dialect of the OpenGL Shading Language. See [Core Image Kernel Language Reference](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Reference/CIKernelLangRef/Introduction/Introduction.html#//apple_ref/doc/uid/TP40004397) and [Core Image Programming Guide](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Conceptual/CoreImaging/ci_intro/ci_intro.html#//apple_ref/doc/uid/TP30001185) for more details.

## See Also

  [Core Image Programming Guide](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Conceptual/CoreImaging/ci_intro/ci_intro.html#//apple_ref/doc/uid/TP30001185)

  [Core Image Kernel Language Reference](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Reference/CIKernelLangRef/Introduction/Introduction.html#//apple_ref/doc/uid/TP40004397)


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