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

# bumpDistortionLinear()

Linearly distorts an image with a concave or convex bump.

## Declaration

```swift
class func bumpDistortionLinear() -> any CIFilter & CIBumpDistortionLinear
```

## Return Value

Return Value The distorted image.

## Discussion

Discussion This method applies the bump distortion linear filter to an image. This effect creates a concave or convex bump to a linear portion of the image. The curvature of the bump is defined by the scale property. A value of 0.0 has no effect, while a positive value creates an outward curvature and a negative value creates an inward curvature. The bump distortion linear filter uses the following properties: The following code creates a filter that results in a vertical bump distorting the image: func bumpDistortionLinear(inputImage: CIImage) -> CIImage {     let filter = CIFilter.bumpDistortionLinear()     filter.inputImage = inputImage     filter.center = CGPoint(x: inputImage.extent.midX, y: inputImage.extent.midY)     filter.radius = 500     filter.scale = 0.2     filter.angle = .pi/2     return filter.outputImage! }

## See Also

### Filters

- [bumpDistortion()](coreimage/cifilter-swift.class/bumpdistortion().md)
- [circleSplashDistortion()](coreimage/cifilter-swift.class/circlesplashdistortion().md)
- [circularWrap()](coreimage/cifilter-swift.class/circularwrap().md)
- [displacementDistortion()](coreimage/cifilter-swift.class/displacementdistortion().md)
- [droste()](coreimage/cifilter-swift.class/droste().md)
- [glassDistortion()](coreimage/cifilter-swift.class/glassdistortion().md)
- [glassLozenge()](coreimage/cifilter-swift.class/glasslozenge().md)
- [holeDistortion()](coreimage/cifilter-swift.class/holedistortion().md)
- [lightTunnel()](coreimage/cifilter-swift.class/lighttunnel().md)
- [ninePartStretched()](coreimage/cifilter-swift.class/ninepartstretched().md)
- [ninePartTiled()](coreimage/cifilter-swift.class/nineparttiled().md)
- [pinchDistortion()](coreimage/cifilter-swift.class/pinchdistortion().md)
- [stretchCrop()](coreimage/cifilter-swift.class/stretchcrop().md)
- [torusLensDistortion()](coreimage/cifilter-swift.class/toruslensdistortion().md)
- [twirlDistortion()](coreimage/cifilter-swift.class/twirldistortion().md)