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# morphologyMinimum()

Blurs a circular area by reducing contrasting pixels.

```
class func morphologyMinimum() -> any CIFilter & CIMorphologyMinimum
```

## Return Value

The blurred image.

## Discussion

This method applies the morphology minimum filter to an image. The effect targets a circular section of the image, calculating the median color values to find colors that make up more than half the working area. Using this calculation, the effect reduces the pixels with contrasting colors to take up less of the working area. The effect is then repeated throughout the image.

The morphology minimum filter uses the following properties:

- `radius`: A `float` representing the area of effect as an <doc://com.apple.documentation/documentation/Foundation/NSNumber>.
- `inputImage`: A [`CIImage`](/documentation/CoreImage/CIImage) representing the input image to apply the filter to.

The following code creates a filter that adds a blur that adds darkness to the input image:

```swift
    func morphologyMinimum(inputImage: CIImage) -> CIImage? {

        let morphologyMinimumFilter = CIFilter.morphologyMinimum()
        morphologyMinimumFilter.inputImage = inputImage
        morphologyMinimumFilter.radius = 5
        return morphologyMinimumFilter.outputImage
    }
```

![Two photographs of a beach at sunset with multiple palm trees. The photo on the left is clear and crisp. In the photo on the right, a morphology minimum blur has been applied, making the image hazy and the edges of the palm trees darker and less distinct.](images/com.apple.coreimage/media-3544966@2x.png)

---

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