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# vImageCVImageFormat_SetUserData(_:_:_:)

Sets the user data of a Core Video image format.

```
func vImageCVImageFormat_SetUserData(_ format: vImageCVImageFormat, _ userData: UnsafeMutableRawPointer!, _ userDataReleaseCallback: ((vImageCVImageFormat?, UnsafeMutableRawPointer?) -> Void)!) -> vImage_Error
```

## Parameters

`format`

The Core Video image format to update.

`userData`

The new user data for the format.

`userDataReleaseCallback`

The callback the system calls when it releases the [`vImageCVImageFormat`](/documentation/Accelerate/vImageCVImageFormat) instance or overwrites the `userData` pointer.

## Return Value

[`kvImageNoError`](/documentation/Accelerate/kvImageNoError); otherwise, one of the error codes in <doc://com.apple.documentation/documentation/Accelerate/data-types-and-constants>.

## Discussion

---

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