---
title: "vImageCVImageFormat_SetAlphaHint(_:_:)"
framework: accelerate
role: symbol
role_heading: Function
path: "accelerate/vimagecvimageformat_setalphahint(_:_:)"
---

# vImageCVImageFormat_SetAlphaHint(_:_:)

Sets the alpha hint of a Core Video image format.

## Declaration

```swift
func vImageCVImageFormat_SetAlphaHint(_ format: vImageCVImageFormat, _ alphaIsOne: Int32) -> vImage_Error
```

## Parameters

- `format`: The Core Video image format to update.
- `alphaIsOne`: The new value of the alpha hint.

## Return Value

Return Value kvImageNoError; otherwise, one of the error codes in Data Types and Constants.

## Discussion

Discussion When an image format contains an alpha channel, but the image is fully opaque, set this property to a nonzero value.

## See Also

### Related Documentation

- [alphaIsOpaqueHint](accelerate/vimagecvimageformat/alphaisopaquehint.md)

### Querying and setting the alpha hint

- [vImageCVImageFormat_GetAlphaHint(_:)](accelerate/vimagecvimageformat_getalphahint(_:).md)