kCGImageDestinationPreserveGainMap
A Boolean value that indicates whether to include a HEIF-embedded gain map in the image data.
Declaration
let kCGImageDestinationPreserveGainMap: CFStringDiscussion
The value of this key must be a CFBoolean value. The default value is kCFBooleanFalse. If you scale the destination image using the kCGImageDestinationImageMaxPixelSize key, the destination also scales the gain map.
See Also
Configuring the Image Behaviors
kCGImageDestinationLossyCompressionQualitykCGImageDestinationBackgroundColorkCGImageDestinationDateTimekCGImageDestinationEmbedThumbnailkCGImageDestinationImageMaxPixelSizekCGImageDestinationMetadatakCGImageDestinationMergeMetadatakCGImageDestinationOptimizeColorForSharingkCGImageDestinationOrientationkCGImageMetadataShouldExcludeGPSkCGImageMetadataShouldExcludeXMP