---
title: premultiplyingAlpha()
framework: coreimage
role: symbol
role_heading: Instance Method
path: coreimage/ciimage/premultiplyingalpha()
---

# premultiplyingAlpha()

Returns a new image created by multiplying the image’s RGB values by its alpha values.

## Declaration

```swift
func premultiplyingAlpha() -> CIImage
```

## Return Value

Return Value An image object representing the result of the operation.

## Discussion

Discussion Premultiplied alpha speeds up the rendering of images, so Core Image filters require that input image data be premultiplied. If you have an image without premultiplied alpha that you want to feed into a filter, use this method before applying the filter.

## See Also

### Creating an Image by Modifying an Existing Image

- [applyingFilter(_:parameters:)](coreimage/ciimage/applyingfilter(_:parameters:).md)
- [applyingFilter(_:)](coreimage/ciimage/applyingfilter(_:).md)
- [transformed(by:)](coreimage/ciimage/transformed(by:).md)
- [transformed(by:highQualityDownsample:)](coreimage/ciimage/transformed(by:highqualitydownsample:).md)
- [cropped(to:)](coreimage/ciimage/cropped(to:).md)
- [oriented(forExifOrientation:)](coreimage/ciimage/oriented(forexiforientation:).md)
- [clampedToExtent()](coreimage/ciimage/clampedtoextent().md)
- [clamped(to:)](coreimage/ciimage/clamped(to:).md)
- [composited(over:)](coreimage/ciimage/composited(over:).md)
- [convertingWorkingSpaceToLab()](coreimage/ciimage/convertingworkingspacetolab().md)
- [convertingLabToWorkingSpace()](coreimage/ciimage/convertinglabtoworkingspace().md)
- [matchedToWorkingSpace(from:)](coreimage/ciimage/matchedtoworkingspace(from:).md)
- [matchedFromWorkingSpace(to:)](coreimage/ciimage/matchedfromworkingspace(to:).md)
- [unpremultiplyingAlpha()](coreimage/ciimage/unpremultiplyingalpha().md)
- [settingAlphaOne(in:)](coreimage/ciimage/settingalphaone(in:).md)