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

# maskedVariableBlur()

Blurs a specified portion of an image.

## Declaration

```swift
class func maskedVariableBlur() -> any CIFilter & CIMaskedVariableBlur
```

## Mentioned in

Selectively Focusing on an Image

## Return Value

Return Value The blurred image.

## Discussion

Discussion This method applies the masked variable blur to an image. The effect blurs the image in an area defined by the mask image. The mask image contains shades of grey that define the strength of the blur. Black colors in the mask cause no blurring, and white colors cause maximum blur. The masked variable blur filter uses the following properties: The following code creates a filter that adds a blur to the bottom of the input image: func maskedVariableBlur(inputImage: CIImage) -> CIImage {     let filter = CIFilter.maskedVariableBlur()     filter.inputImage = inputImage     // Create a mask that goes from white to black vertially.     let mask = CIFilter.smoothLinearGradient()     mask.color0 = CIColor.white     mask.color1 = CIColor.black     mask.point0 = CGPoint(x: 0, y: 0)     mask.point1 = CGPoint(x:0, y: inputImage.extent.height)     filter.mask = mask.outputImage     filter.radius = 25     return filter.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)
- [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)
- [noiseReduction()](coreimage/cifilter-swift.class/noisereduction().md)
- [zoomBlur()](coreimage/cifilter-swift.class/zoomblur().md)