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Day 54 - Instafilter, part 4...Applying filters...Error: "Thread 1: Exception: "[<CITwirlDistortion 0x600002ccea00> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key inputIntensity."

Forums > 100 Days of Swift

I seem to be getting this error for some of my filters. Not all of them.

The crash occures when I choose an image and then select one of these filter types:

  • bump distortion
  • gaussian blur
  • pixellate
  • twirl distortion

I've checked the documentation for deprecated values, but I am not seeing any changes... probably something small I'm not seeing?

import CoreImage
import UIKit

class ViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    @IBOutlet var imageView: UIImageView!
    @IBOutlet var intensity: UISlider!
    var currentImage: UIImage!

    var context: CIContext!
    var currentFilter: CIFilter!

    override func viewDidLoad() {
        super.viewDidLoad()

        title = "YACIFP"
        navigationItem.rightBarButtonItem = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(importPicture))

        context = CIContext()
        currentFilter = CIFilter(name: "CISepiaTone")
    }

    @objc func importPicture() {
        let picker = UIImagePickerController()
        picker.allowsEditing = true
        picker.delegate = self
        present(picker, animated: true)
    }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        guard let image = info[.editedImage] as? UIImage else { return }
        dismiss(animated: true)
        currentImage = image

        let beginImage = CIImage(image: currentImage)
        currentFilter.setValue(beginImage, forKey: kCIInputImageKey)
        applyProcessing()
    }

    @IBAction func changeFilter(_ sender: UIButton) {
        let ac = UIAlertController(title: "Choose filter", message: nil, preferredStyle: .actionSheet)
        ac.addAction(UIAlertAction(title: "CIBumpDistortion", style: .default, handler: setFilter))
        ac.addAction(UIAlertAction(title: "CIGaussianBlur", style: .default, handler: setFilter))
        ac.addAction(UIAlertAction(title: "CIPixellate", style: .default, handler: setFilter))
        ac.addAction(UIAlertAction(title: "CISepiaTone", style: .default, handler: setFilter))
        ac.addAction(UIAlertAction(title: "CITwirlDistortion", style: .default, handler: setFilter))
        ac.addAction(UIAlertAction(title: "CIUnsharpMask", style: .default, handler: setFilter))
        ac.addAction(UIAlertAction(title: "CIVignette", style: .default, handler: setFilter))
        ac.addAction(UIAlertAction(title: "Cancel", style: .cancel))

        if let popOverController = ac.popoverPresentationController {
            popOverController.sourceView = sender
            popOverController.sourceRect = sender.bounds
        }

        present(ac, animated: true)
    }

    func setFilter(action: UIAlertAction) {
        // make sure we have a valid image before continuing!
        guard currentImage != nil else { return }

        // safely read the alert action's title
        guard let actionTitle = action.title else { return }

        currentFilter = CIFilter(name: actionTitle)

        let beginImage = CIImage(image: currentImage)
        currentFilter.setValue(beginImage, forKey: kCIInputImageKey)

        applyProcessing()
    }

    @IBAction func save(_ sender: Any) {
        guard let image = imageView.image else { return }
        UIImageWriteToSavedPhotosAlbum(image, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)
    }

    @IBAction func intensityChanged(_ sender: Any) {
        applyProcessing()
    }

    func applyProcessing() {
        let inputKeys = currentFilter.inputKeys

        if inputKeys.contains(kCIInputIntensityKey) { currentFilter.setValue(intensity.value, forKey: kCIInputIntensityKey) }
        if inputKeys.contains(kCIInputRadiusKey) { currentFilter.setValue(intensity.value * 200, forKey: kCIInputRadiusKey) }
        if inputKeys.contains(kCIInputScaleKey) { currentFilter.setValue(intensity.value * 10, forKey: kCIInputScaleKey) }
        if inputKeys.contains(kCIInputCenterKey) { currentFilter.setValue(CIVector(x: currentImage.size.width / 2, y: currentImage.size.height / 2), forKey: kCIInputCenterKey) }

        guard let image = currentFilter.outputImage else { return }

        currentFilter.setValue(intensity.value, forKey: kCIInputIntensityKey)

        if let cgimg = context.createCGImage(image, from: image.extent) {
            let processedImage = UIImage(cgImage: cgimg)
            imageView.image = processedImage
        }
    }

    @objc func image(_ image: UIImage, didFinishSavingWithError error: Error?, contextInfo: UnsafeRawPointer) {
        if let error = error {
            let ac = UIAlertController(title: "Save error", message: error.localizedDescription, preferredStyle: .alert)
            ac.addAction(UIAlertAction(title: "OK", style: .default))
        } else {
            let ac = UIAlertController(title: "Saved!", message: "Your altered image has been saved to your photos", preferredStyle: .alert)
            ac.addAction(UIAlertAction(title: "OK", style: .default))
            present(ac, animated: true)
        }
    }

}

3      

Hi there! I suspect the issue in the function for applying filters

func applyProcessing() {
        let inputKeys = currentFilter.inputKeys

        if inputKeys.contains(kCIInputIntensityKey) { currentFilter.setValue(intensity.value, forKey: kCIInputIntensityKey) }
        if inputKeys.contains(kCIInputRadiusKey) { currentFilter.setValue(intensity.value * 200, forKey: kCIInputRadiusKey) }
        if inputKeys.contains(kCIInputScaleKey) { currentFilter.setValue(intensity.value * 10, forKey: kCIInputScaleKey) }
        if inputKeys.contains(kCIInputCenterKey) { currentFilter.setValue(CIVector(x: currentImage.size.width / 2, y: currentImage.size.height / 2), forKey: kCIInputCenterKey) }

        guard let image = currentFilter.outputImage else { return }

        currentFilter.setValue(intensity.value, forKey: kCIInputIntensityKey) // <- this line overrides previous filters you set, so if you remove this it should solve the issue

        if let cgimg = context.createCGImage(image, from: image.extent) {
            let processedImage = UIImage(cgImage: cgimg)
            imageView.image = processedImage
        }
    }

3      

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