How to filter images using Core Image and CIFilter
Core Image is the one of the most powerful frameworks available to iOS developers: it makes hardware-accelerated image manipulation ridiculously easy, which means you get to add powerful graphical effects to your apps and games with very little work.
Most of the work is done by choosing the right CIFilter. Apple's official documentation goes into great detail about the various filters you can use, and you can also read Hacking with Swift project 13 for a hands-on tutorial showing off various effects. The code below applies a 50% sepia tone effect to an image:
let inputImage = UIImage(named: "taylor-swift")!
let context = CIContext(options: nil)
if let currentFilter = CIFilter(name: "CISepiaTone") {
let beginImage = CIImage(image: inputImage)
currentFilter.setValue(beginImage, forKey: kCIInputImageKey)
currentFilter.setValue(0.5, forKey: kCIInputIntensityKey)
if let output = currentFilter.outputImage {
if let cgimg = context.createCGImage(output, from: output.extent) {
let processedImage = UIImage(cgImage: cgimg)
// do something interesting with the processed image
}
}
}Available from iOS 5.0 – see Hacking with Swift tutorial 13
Did this solution work for you? Please pass it on!
Other people are reading…
- How to create a PDF417 barcode
- How to loop audio using AVAudioPlayer and numberOfLoops
- How to play videos using AVPlayerViewController
- How to desaturate an image to make it black and white
- How to turn on the camera flashlight to make a torch
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
