# vImageCVImageFormat_GetChromaSiting(_:) Returns the chrominance siting of a Core Video image format. ``` func vImageCVImageFormat_GetChromaSiting(_ format: vImageConstCVImageFormat) -> Unmanaged! ``` ## Parameters `format` The Core Video image format to query. ## Return Value A that describes the positioning of the chrominance samples. ## Discussion 4:2:0 and 4:2:0 YpCbCr image formats that have subsampled chrominance require the position of the chrominance samples relative to the luminance samples. The functions that create Core Video image formats, such as [`vImageCVImageFormat_CreateWithCVPixelBuffer(_:)`](/documentation/Accelerate/vImageCVImageFormat_CreateWithCVPixelBuffer(_:)), return a [`vImageCVImageFormat`](/documentation/Accelerate/vImageCVImageFormat). The following code shows how you create a [`vImageConstCVImageFormat`](/documentation/Accelerate/vImageConstCVImageFormat) representation of a [`vImageCVImageFormat`](/documentation/Accelerate/vImageCVImageFormat) instance to pass to [`vImageCVImageFormat_GetChromaSiting(_:)`](/documentation/Accelerate/vImageCVImageFormat_GetChromaSiting(_:)): ```swift let chromaSiting = withUnsafeBytes(of: cvImageFormat) { bytes in let format = bytes.assumingMemoryBound( to: vImageConstCVImageFormat.self).first! return vImageCVImageFormat_GetChromaSiting(format) } ``` ## See Also [`chromaSiting`](/documentation/Accelerate/vImageCVImageFormat/chromaSiting-swift.property) The chrominance siting of the Core Video image format. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)