Contents

areaAverage()

Returns a 1 x 1 pixel image that contains the average color for the region of interest.

Declaration

class func areaAverage() -> any CIFilter & CIAreaAverage

Return Value

A 1 x 1 pixel image containing the average color for the region of interest.

Discussion

This filter calculates the average color of the area defined by extent and creates a 1 x 1 pixel image with the result. The filter processes each color component (red, green, blue, alpha) of the input image independently.

The area average filter uses the following properties:

inputImage

The CIImage containing the image you want to process.

extent

A CGRect that specifies the region of the image that you want to process.

The following code creates a filter that calculates the average color of a 500 x 500 set of pixels from the center of the image:

func averageArea(inputImage: CIImage) -> CIImage {
    let filter = CIFilter.areaAverage()
    filter.inputImage = inputImage
    filter.extent = CGRect(
        x: inputImage.extent.width/2-250,
        y: inputImage.extent.height/2-250,
        width: 500,
        height: 500)
    return filter.outputImage!
}

[Image]

See Also

Filters