CODEWITHSUNDEEP
iosxcodeswift2
Mehdi Haghgoo
Mehdi Haghgoo

Reputation: 3484

How to apply a filter to an image in Image View

I want to create an image filtering app that applies a random filter to an image in an Image View. I followed a 2014 Apple tutorial. As per Xcode errors and warnings, now I have the following code in ViewController.swift. 

import UIKit

class ViewController: UIViewController {


    @IBOutlet weak var photoImageView: UIImageView!

    // Create a place to render the filtered image
    let context = CIContext(options: nil)

    @IBAction func applyFilter(_ sender: Any) {
        // Create an image to filter
        let inputImage = CIImage(image: photoImageView.image!)

        // Create a random color to pass to a filter
        let randomColor = [kCIInputAngleKey: (Double(arc4random_uniform(314)) / 100)]

        // Apply a filter to the image
        let filteredImage = inputImage?.applyingFilter("CIHueAdjust", parameters: randomColor)

        // Render the filtered image
        let renderedImage = context.createCGImage(filteredImage!, from: filteredImage!.extent)

        // Reflect the change back in the interface
        //photoImageView.image = UIImage(CGImage: renderedImage!)
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

enter image description here The code before the last commented statement is successfully built. I had to comment the statement because it gave the error Ambiguous use of init(CGImage). The code has no effect currently. It just shows an Image View and a bar button below it (clicking the button does not do anything). Note that my code is slightly different from that of the tutorial, as the tutorial code seems deprecated. Any ideas why the code does not work?

The following is the code from the original tutorial: 

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var photoImageView: UIImageView!

    // Create a place to render the filtered image
    let context = CIContext(options: nil)

    @IBAction func applyFilter(sender: AnyObject) {

        // Create an image to filter
        let inputImage = CIImage(image: photoImageView.image)

        // Create a random color to pass to a filter
        let randomColor = [kCIInputAngleKey: (Double(arc4random_uniform(314)) / 100)]

        // Apply a filter to the image
        let filteredImage = inputImage.imageByApplyingFilter("CIHueAdjust", withInputParameters: randomColor)

        // Render the filtered image
        let renderedImage = context.createCGImage(filteredImage, fromRect: filteredImage.extent())

        // Reflect the change back in the interface
        photoImageView.image = UIImage(CGImage: renderedImage)

    }

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

Upvotes: 0

Views: 1920

Answers (2)

djromero
djromero

Reputation: 19641

Your code shouldn't build.

Once you fix the core image filter name, try replacing:

photoImageView.image = UIImage(CGImage: renderedImage!)

with:

photoImageView.image = UIImage(cgImage: renderedImage!)
//                             ^
//                             |
//                  attention to capitalization

Upvotes: 1

Amrit Trivedi
Amrit Trivedi

Reputation: 1270

There is typo in core image filter name. Also try to run your code in device.

Upvotes: 0

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