What is the best Core Image filter to produce black and white effects?

Question

I am using Core Image and would like to produce a black and white effect on the chosen image.

Ideally I would like to have access to the same sort of options that a

Answer 1

Here is the most liked answer from @Shmidt written as an UIImage extension with a performance update in Swift:

import CoreImage

extension UIImage
{
    func imageBlackAndWhite() -> UIImage?
    {
        if let beginImage = CoreImage.CIImage(image: self)
        {
            let paramsColor: [String : AnyObject] = [kCIInputBrightnessKey: NSNumber(double: 0.0),
                                                     kCIInputContrastKey:   NSNumber(double: 1.1),
                                                     kCIInputSaturationKey: NSNumber(double: 0.0)]
            let blackAndWhite = beginImage.imageByApplyingFilter("CIColorControls", withInputParameters: paramsColor)

            let paramsExposure: [String : AnyObject] = [kCIInputEVKey: NSNumber(double: 0.7)]
            let output = blackAndWhite.imageByApplyingFilter("CIExposureAdjust", withInputParameters: paramsExposure)

            let processedCGImage = CIContext().createCGImage(output, fromRect: output.extent)
            return UIImage(CGImage: processedCGImage, scale: self.scale, orientation: self.imageOrientation)
        }
        return nil
    }
}