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

# toneCurve()

Alters an image’s tone curve according to a series of data points.

## Declaration

```swift
class func toneCurve() -> any CIFilter & CIToneCurve
```

## Return Value

Return Value The modified image.

## Discussion

Discussion This method applies the tone curve filter to an image. The effect calculates the adjustment of the tone curve by the sum of the red, green, and blue color values with the point value properties specified. The tone curve filter uses the following properties: The following code creates a filter that adds brightness to the input image: func toneCurve(inputImage: CIImage) -> CIImage {     let toneCurveFilter = CIFilter.toneCurve()     toneCurveFilter.inputImage = inputImage     toneCurveFilter.point0 = CGPoint(x: 0, y: 0)     toneCurveFilter.point1 = CGPoint(x: 0.22, y: 0.25)     toneCurveFilter.point2 = CGPoint(x: 0.4, y: 0.5)     toneCurveFilter.point3 = CGPoint(x: 0.65, y: 0.75)     toneCurveFilter.point4 = CGPoint(x: 1, y: 1)     return toneCurveFilter.outputImage! }

## See Also

### Filters

- [colorAbsoluteDifference()](coreimage/cifilter-swift.class/colorabsolutedifference().md)
- [colorClamp()](coreimage/cifilter-swift.class/colorclamp().md)
- [colorControls()](coreimage/cifilter-swift.class/colorcontrols().md)
- [colorMatrix()](coreimage/cifilter-swift.class/colormatrix().md)
- [colorPolynomial()](coreimage/cifilter-swift.class/colorpolynomial().md)
- [colorThreshold()](coreimage/cifilter-swift.class/colorthreshold().md)
- [colorThresholdOtsu()](coreimage/cifilter-swift.class/colorthresholdotsu().md)
- [depthToDisparity()](coreimage/cifilter-swift.class/depthtodisparity().md)
- [disparityToDepth()](coreimage/cifilter-swift.class/disparitytodepth().md)
- [exposureAdjust()](coreimage/cifilter-swift.class/exposureadjust().md)
- [gammaAdjust()](coreimage/cifilter-swift.class/gammaadjust().md)
- [hueAdjust()](coreimage/cifilter-swift.class/hueadjust().md)
- [linearToSRGBToneCurve()](coreimage/cifilter-swift.class/lineartosrgbtonecurve().md)
- [sRGBToneCurveToLinear()](coreimage/cifilter-swift.class/srgbtonecurvetolinear().md)
- [temperatureAndTint()](coreimage/cifilter-swift.class/temperatureandtint().md)