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# softLightBlendMode()

Blurs the colors of two images by calculating luminance.

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

## Return Value

The modified image.

## Discussion

This method applies the soft-light blend mode filter to an image. The effect calculates the brightness of the colors in the background image. Colors that are lighter than 50 percent gray become lighter, while the filter further darkens colors that are darker than 50 percent. The filter then uses the calculated result to create the output image.

The soft-light 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 results in the image becoming slightly darker with more saturation and the colors of the gradient image:

```swift
func softLightBlendMode(inputImage: CIImage, backgroundImage: CIImage) -> CIImage {
    let colorBlendFilter = CIFilter.softLightBlendMode()
    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 a soft-light blend mode filter. The result displays more of the gradient photo’s colors overlaid on the rainbow beach image, resulting in a darker image. ](images/com.apple.coreimage/media-3546420@2x.png)

---

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