---
title: "vImageCVImageFormat_GetChromaSiting(_:)"
framework: accelerate
role: symbol
role_heading: Function
path: "accelerate/vimagecvimageformat_getchromasiting(_:)"
---

# vImageCVImageFormat_GetChromaSiting(_:)

Returns the chrominance siting of a Core Video image format.

## Declaration

```swift
func vImageCVImageFormat_GetChromaSiting(_ format: vImageConstCVImageFormat) -> Unmanaged<CFString>!
```

## Parameters

- `format`: The Core Video image format to query.

## Return Value

Return Value A CFString that describes the positioning of the chrominance samples.

## Discussion

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(_:), return a vImageCVImageFormat. The following code shows how you create a vImageConstCVImageFormat representation of a vImageCVImageFormat instance to pass to vImageCVImageFormat_GetChromaSiting(_:): let chromaSiting = withUnsafeBytes(of: cvImageFormat) { bytes in     let format = bytes.assumingMemoryBound(         to: vImageConstCVImageFormat.self).first!          return vImageCVImageFormat_GetChromaSiting(format) }

## See Also

### Related Documentation

- [chromaSiting](accelerate/vimagecvimageformat/chromasiting-swift.property.md)

### Querying and setting the chrominance siting

- [vImageCVImageFormat_SetChromaSiting(_:_:)](accelerate/vimagecvimageformat_setchromasiting(_:_:).md)