Contents

areaMaximumAlpha()

Finds the pixel with the highest alpha value.

Declaration

class func areaMaximumAlpha() -> any CIFilter & CIAreaMaximumAlpha

Return Value

A 1 x 1 size image containing the pixel with the maximum alpha value.

Discussion

This filter returns the pixel with highest alpha value in the region defined by extent.

The area maximum alpha filter uses the following properties:

inputImage

An image with the type CIImage.

extent

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

The following code creates a filter that results in a single pixel image containing the pixel with the highest alpha value:

func areaMaximumAlpha(inputImage: CIImage) -> CIImage {
    let filter = CIFilter.areaMaximumAlpha()
    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