---
title: hdrGainMapAsRGB
framework: coreimage
role: symbol
role_heading: Type Property
path: coreimage/ciimagerepresentationoption/hdrgainmapasrgb
---

# hdrGainMapAsRGB

An optional key and value to request the gain map channel to be color instead of monochrome.

## Declaration

```swift
static let hdrGainMapAsRGB: CIImageRepresentationOption
```

## Discussion

Discussion This key affects how the gain map image is calculated from the SDR receiver and the hdrImage image value. The value for this is a Boolean where: True: the gain map is created as a color ratio between the HDR and SDR images. False: the gain map is created as a brightness ratio between the HDR and SDR images. Not specified: the default behavior False.