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

# documentEnhancer()

Adjusts an image’s shadows and contrast.

## Declaration

```swift
class func documentEnhancer() -> any CIFilter & CIDocumentEnhancer
```

## Return Value

Return Value The modified image.

## Discussion

Discussion This method applies the document enhancer filter to an image. The effect removes unwanted shadows while whitening the background and enhancing contrast. The filter is commonly used to enhance scanned documents. The document enhancer filter uses the following properties: The following code creates a filter that adds brightness to the input image: func documentEnhancer(inputImage: CIImage) -> CIImage {     let documentEnhancerFilter = CIFilter.documentEnhancer()     documentEnhancerFilter.inputImage = inputImage     documentEnhancerFilter.amount = 4     return documentEnhancerFilter.outputImage! }

## See Also

### Color Effect Filters

- [colorCrossPolynomial()](coreimage/cifilter-swift.class/colorcrosspolynomial().md)
- [colorCube()](coreimage/cifilter-swift.class/colorcube().md)
- [colorCubeWithColorSpace()](coreimage/cifilter-swift.class/colorcubewithcolorspace().md)
- [colorCubesMixedWithMask()](coreimage/cifilter-swift.class/colorcubesmixedwithmask().md)
- [colorCurves()](coreimage/cifilter-swift.class/colorcurves().md)
- [colorInvert()](coreimage/cifilter-swift.class/colorinvert().md)
- [colorMap()](coreimage/cifilter-swift.class/colormap().md)
- [colorMonochrome()](coreimage/cifilter-swift.class/colormonochrome().md)
- [colorPosterize()](coreimage/cifilter-swift.class/colorposterize().md)
- [convertLabToRGB()](coreimage/cifilter-swift.class/convertlabtorgb().md)
- [convertRGBtoLab()](coreimage/cifilter-swift.class/convertrgbtolab().md)
- [dither()](coreimage/cifilter-swift.class/dither().md)
- [falseColor()](coreimage/cifilter-swift.class/falsecolor().md)
- [labDeltaE()](coreimage/cifilter-swift.class/labdeltae().md)
- [maskToAlpha()](coreimage/cifilter-swift.class/masktoalpha().md)