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

# lineOverlay()

Creates an image that resembles a sketch of the outlines of objects.

## Declaration

```swift
class func lineOverlay() -> any CIFilter & CILineOverlay
```

## Return Value

Return Value The modified image.

## Discussion

Discussion This method applies the line overlay filter to an image. The effect creats a sketch that outlines the edges of the image in black, leaving the non-outlined portion of the image transparent. The line overlay filter uses the following properties: The following code creates a filter that results in a monochrome image with lines outlining the edges of objects: func lineOverlay(inputImage: CIImage) -> CIImage {     let lineOverlay = CIFilter.lineOverlay()     lineOverlay.inputImage = inputImage     lineOverlay.nrNoiseLevel = 0.07     lineOverlay.nrSharpness = 0.71     lineOverlay.edgeIntensity = 1     lineOverlay.threshold = 0.1     lineOverlay.contrast = 50.00     return lineOverlay.outputImage! }

## See Also

### Filters

- [blendWithAlphaMask()](coreimage/cifilter-swift.class/blendwithalphamask().md)
- [blendWithBlueMask()](coreimage/cifilter-swift.class/blendwithbluemask().md)
- [blendWithMask()](coreimage/cifilter-swift.class/blendwithmask().md)
- [blendWithRedMask()](coreimage/cifilter-swift.class/blendwithredmask().md)
- [bloom()](coreimage/cifilter-swift.class/bloom().md)
- [cannyEdgeDetector()](coreimage/cifilter-swift.class/cannyedgedetector().md)
- [comicEffect()](coreimage/cifilter-swift.class/comiceffect().md)
- [coreMLModel()](coreimage/cifilter-swift.class/coremlmodel().md)
- [crystallize()](coreimage/cifilter-swift.class/crystallize().md)
- [depthOfField()](coreimage/cifilter-swift.class/depthoffield().md)
- [edges()](coreimage/cifilter-swift.class/edges().md)
- [edgeWork()](coreimage/cifilter-swift.class/edgework().md)
- [gaborGradients()](coreimage/cifilter-swift.class/gaborgradients().md)
- [gloom()](coreimage/cifilter-swift.class/gloom().md)
- [heightFieldFromMask()](coreimage/cifilter-swift.class/heightfieldfrommask().md)