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  "title" : "darkenBlendMode()"
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# darkenBlendMode()

Blends colors from two images while darkening lighter pixels.

```
class func darkenBlendMode() -> any CIFilter & CICompositeOperation
```

## Return Value

The modified image.

## Discussion

This method applies the darken-blend mode filter to an image. The effect targets lighter colors in the background image and darkens them, while darker colors remain unchanged. The result is the sum of the adjusted color values from both images.

The darken-blend mode filter uses the following properties:

- `inputImage`: An image with the type [`CIImage`](/documentation/CoreImage/CIImage).
- `backgroundImage`: An image with the type [`CIImage`](/documentation/CoreImage/CIImage).

The following code creates a filter that darkens the image:

```swift
func darkenBlendMode(inputImage: CIImage, backgroundImage: CIImage) -> CIImage {
    let colorBlendFilter = CIFilter.darkenBlendMode()
    colorBlendFilter.inputImage = inputImage
    colorBlendFilter.backgroundImage = backgroundImage
    return colorBlendFilter.outputImage!
}
```

![The image on the top left shows a beach with multiple palm trees and a rainbow arching across the blue sky.  The image below is a gradient image displaying a gradual color shift from purple to a dark orange. The image on the right shows the output from applying the color darken blend mode filter. The results displays colors from both images and has added darkness.](images/com.apple.coreimage/media-3546416@2x.png)

---

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