ios – CIAreaMaximum all the time return RGB(255,255,255)


I tried to detect main colour by CIAreaMaximum. However I can solely get the white colour(rgb:255,255,255) in consequence irrespective of no matter image I enter. Do I misunderstand the operate of CIAreaMaximum? Any assist shall be appreciated.

struct ContentView: View {
    let img = UIImage(named: "leaf") ?? UIImage()
    var physique: some View {
        VStack {
            Picture(uiImage: img)
            Textual content("max")
            Colour(uiColor: img.maxColor ?? .systemPink)
                .body(peak: 50)

extension UIImage {
    var maxColor: UIColor? {
        guard let inputImage = CIImage(picture: self) else { return nil }
        let extentVector = CIVector(x: inputImage.extent.origin.x, y: inputImage.extent.origin.y, z: inputImage.extent.dimension.width, w: inputImage.extent.dimension.peak)
        guard let filter = CIFilter(title: "CIAreaMaximum", parameters: [kCIInputImageKey: inputImage, kCIInputExtentKey: extentVector]) else { return nil }
        guard let outputImage = filter.outputImage else { return nil }
        var bitmap = [UInt8](repeating: 0, depend: 4)
        let context = CIContext(choices: [.workingColorSpace: kCFNull as Any])
        context.render(outputImage, toBitmap: &bitmap, rowBytes: 4, bounds: CGRect(x: 0, y: 0, width: 1, peak: 1), format: .RGBA8, colorSpace: nil)
        return UIColor(crimson: CGFloat(bitmap[0])/255, inexperienced: CGFloat(bitmap[1])/255, blue: CGFloat(bitmap[2])/255, alpha: CGFloat(bitmap[3])/255)