---
title: sharpenLuminance()
framework: coreimage
role: symbol
role_heading: Type Method
path: coreimage/cifilter-swift.class/sharpenluminance()
---

# sharpenLuminance()

Applies a sharpening effect to an image.

## Declaration

```swift
class func sharpenLuminance() -> any CIFilter & CISharpenLuminance
```

## Return Value

Return Value The modified image.

## Discussion

Discussion This method applies the sharpen luminance filter to an image. The effect increases image detail by adjusting the luminance of each pixel within the radius property. Sharpening the luminance doesn’t effect the chroma data of each pixel. The bicubic sharpen luminance filter uses the following properties: The following code creates a filter that results in detail from the sign in the image to be more visible: func sharpen (inputImage: CIImage) -> CIImage? {     let sharpenLuminance = CIFilter.sharpenLuminance()     sharpenLuminance.inputImage = inputImage     sharpenLuminance.radius = 10     sharpenLuminance.sharpness = 1     return sharpenLuminance.outputImage! }

## See Also

### Filters

- [unsharpMask()](coreimage/cifilter-swift.class/unsharpmask().md)