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

# noiseReduction()

Reduces noise by sharpening the edges of objects.

## Declaration

```swift
class func noiseReduction() -> any CIFilter & CINoiseReduction
```

## Return Value

Return Value The blurred image.

## Discussion

Discussion This method applies the noise reduction filter to an image. The effect calculates changes in luminance below the noise level and locally blurs the area. Values above the threshold are determined to be edges, and become sharpened. The morphology noise reduction filter uses the following properties: The following code creates a filter that reduces noise in the input image:     func noiseReduction(inputImage: CIImage) -> CIImage? {

let noiseReductionfilter = CIFilter.noiseReduction()         noiseReductionfilter.inputImage = inputImage         noiseReductionfilter.noiseLevel = 0.2         noiseReductionfilter.sharpness = 0.4         return noiseReductionfilter.outputImage     }

## See Also

### Filters

- [bokehBlur()](coreimage/cifilter-swift.class/bokehblur().md)
- [boxBlur()](coreimage/cifilter-swift.class/boxblur().md)
- [discBlur()](coreimage/cifilter-swift.class/discblur().md)
- [gaussianBlur()](coreimage/cifilter-swift.class/gaussianblur().md)
- [maskedVariableBlur()](coreimage/cifilter-swift.class/maskedvariableblur().md)
- [median()](coreimage/cifilter-swift.class/median().md)
- [morphologyGradient()](coreimage/cifilter-swift.class/morphologygradient().md)
- [morphologyMaximum()](coreimage/cifilter-swift.class/morphologymaximum().md)
- [morphologyMinimum()](coreimage/cifilter-swift.class/morphologyminimum().md)
- [morphologyRectangleMaximum()](coreimage/cifilter-swift.class/morphologyrectanglemaximum().md)
- [morphologyRectangleMinimum()](coreimage/cifilter-swift.class/morphologyrectangleminimum().md)
- [motionBlur()](coreimage/cifilter-swift.class/motionblur().md)
- [zoomBlur()](coreimage/cifilter-swift.class/zoomblur().md)