---
title: CIKeystoneCorrectionHorizontal
framework: coreimage
role: symbol
role_heading: Protocol
path: coreimage/cikeystonecorrectionhorizontal
---

# CIKeystoneCorrectionHorizontal

The properties you use to configure a keystone correction horizontal filter.

## Declaration

```swift
protocol CIKeystoneCorrectionHorizontal : CIFourCoordinateGeometryFilter
```

## Topics

### Instance Properties

- [focalLength](coreimage/cikeystonecorrectionhorizontal/focallength.md)

## Relationships

### Inherits From

- [CIFilterProtocol](coreimage/cifilterprotocol.md)
- [CIFourCoordinateGeometryFilter](coreimage/cifourcoordinategeometryfilter.md)

## See Also

### Related Documentation

- [keystoneCorrectionHorizontal()](coreimage/cifilter-swift.class/keystonecorrectionhorizontal().md)

### Protocols

- [CIBicubicScaleTransform](coreimage/cibicubicscaletransform.md)
- [CIEdgePreserveUpsample](coreimage/ciedgepreserveupsample.md)
- [CIFourCoordinateGeometryFilter](coreimage/cifourcoordinategeometryfilter.md)
- [CIKeystoneCorrectionCombined](coreimage/cikeystonecorrectioncombined.md)
- [CIKeystoneCorrectionVertical](coreimage/cikeystonecorrectionvertical.md)
- [CILanczosScaleTransform](coreimage/cilanczosscaletransform.md)
- [CIPerspectiveCorrection](coreimage/ciperspectivecorrection.md)
- [CIPerspectiveRotate](coreimage/ciperspectiverotate.md)
- [CIPerspectiveTransform](coreimage/ciperspectivetransform.md)
- [CIPerspectiveTransformWithExtent](coreimage/ciperspectivetransformwithextent.md)
- [CIStraighten](coreimage/cistraighten.md)