---
title: contentHeadroom
framework: coreimage
role: symbol
role_heading: Instance Property
path: coreimage/ciimage/contentheadroom
---

# contentHeadroom

Returns the content headroom of the image.

## Declaration

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

## Discussion

Discussion If the image headroom is unknown, then the value 0.0 will be returned. If the image headroom is known, then a value greater than or equal to 1.0 will be returned. A value of 1.0 will be returned if the image is SDR. A value greater than 1.0 will be returned if the image is HDR. The image headroom may known when a CIImage is first initialized. If the a CIImage is initialized using: NSURL or NSData : the headroom may be determined by associated metadata or deduced from pixel format or colorSpace information. CGImage : headroom may be determined by CGImageGetHeadroomInfo() or deduced from pixel format or colorSpace information. IOSurface : then the headroom will be determined by kIOSurfaceContentHeadroom. or deduced from pixel format or colorSpace information. CVPixelBuffer : then the headroom will be determined by kCVImageBufferContentLightLevelInfoKey. or deduced from pixel format or colorSpace information. BitmapData : headroom may be deduced from pixel format or colorSpace information. If the image is the result of applying a CIFilter or CIKernel, this method will return 0.0. There are exceptions to this.  Applying a CIWarpKernel`` or certain ``CIFilter-class``  (e.g. CIGaussianBlur, CILanczosScaleTransform, CIAreaAverageand some others)  to an image will result in a ``CIImage`` instance with the samecontentHeadroom` property value.

## See Also

### Instance Properties

- [isOpaque](coreimage/ciimage/isopaque.md)
- [metalTexture](coreimage/ciimage/metaltexture.md)