---
title: contentAverageLightLevel
framework: coreimage
role: symbol
role_heading: Instance Property
path: coreimage/ciimage/contentaveragelightlevel
---

# contentAverageLightLevel

Returns the content average light level of the image.

## Declaration

```swift
var contentAverageLightLevel: Float { get }
```

## Discussion

Discussion If the image average light level is unknown, then the value 0.0 will be returned. If the image headroom is known, then a value greater than or equal to 0.0 will be returned. The image average light level may known when a CIImage is first initialized. If the a CIImage is initialized with a: CGImage : then the headroom will be determined by CGImageGetContentAverageLightLevel(). CVPixelBuffer : then the headroom will be determined by kCVImageBufferContentLightLevelInfoKey. If the image is the result of applying a CIFilter or CIKernel, this property will return 0.0. There are exceptions to this.  Applying a CIWarpKernel or certain CIFilter (e.g. CIGaussianBlur, CILanczosScaleTransform, CIAreaAverage and some others) to an image will result in a CIImage instance with the same contentAverageLightLevel property value.