<!--
{
  "documentType" : "article",
  "framework" : "CoreVideo",
  "identifier" : "/documentation/CoreVideo/image-buffer-chroma-subsampling-constants",
  "metadataVersion" : "0.1.0",
  "role" : "collectionGroup",
  "title" : "Image Buffer Chroma Subsampling Constants"
}
-->

# Image Buffer Chroma Subsampling Constants

Constants that indicate the original format of subsampled data in the image buffer before conversion to 422/2vuy format.

## Discussion

Use the [`kCVImageBufferChromaSubsamplingKey`](/documentation/CoreVideo/kCVImageBufferChromaSubsamplingKey) key to attach one of these values to the image buffer.

> Note:
> To use thse constants, ensure that the image buffer data was converted to 4:2:2 format using simple pixel replication.

## Topics

### Constants

[`let kCVImageBufferChromaSubsampling_420: CFString`](/documentation/CoreVideo/kCVImageBufferChromaSubsampling_420)

A key that indicates the original chroma-subsampled data used 4:2:0 formatting.

[`let kCVImageBufferChromaSubsampling_422: CFString`](/documentation/CoreVideo/kCVImageBufferChromaSubsampling_422)

A key that indicates the original chroma-subsampled data used 4:2:2 formatting.

[`let kCVImageBufferChromaSubsampling_411: CFString`](/documentation/CoreVideo/kCVImageBufferChromaSubsampling_411)

A key that indicates the original chroma-subsampled data used 4:1:1 formatting.


---

Copyright &copy; 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)