png transparent image metadata coming with white background

Question

The metadata is pulling a transparent png image from a url. However the UIImageView is not coming in as transparent and has a white background.

Is there a work around this issue?

Perhaps .pngData()

@IBOutlet weak var mainCenterIcon: UIImageView!

func initAudioPlayer() {
        
        let url = URL(string: activeAudioURL) 
        let playerItem:AVPlayerItem = AVPlayerItem(url: url!)
        player = AVPlayer(playerItem: playerItem)
        
        //MetaData to recieve album artwork
        let metadataList = playerItem.asset.metadata
        
        
        for item in metadataList {

            guard let key = item.commonKey?.rawValue, let value = item.value else{
                continue
            }

           switch key {
           case "artwork" where value is Data : mainCenterIcon.image = UIImage(data: value as! Data)
            default:
              continue
           }
        }
    }

score 2 · Accepted Answer · answered Dec 18 '20 at 08:07

I have found a solution:

extension UIImage {
    func imageByMakingWhiteBackgroundTransparent() -> UIImage? {

        let image = UIImage(data: self.jpegData(compressionQuality: 1.0)!)!
        let rawImageRef: CGImage = image.cgImage!

        let colorMasking: [CGFloat] = [222, 255, 222, 255, 222, 255]
        UIGraphicsBeginImageContext(image.size);

        let maskedImageRef = rawImageRef.copy(maskingColorComponents: colorMasking)
        UIGraphicsGetCurrentContext()?.translateBy(x: 0.0,y: image.size.height)
        UIGraphicsGetCurrentContext()?.scaleBy(x: 1.0, y: -1.0)
        UIGraphicsGetCurrentContext()?.draw(maskedImageRef!, in: CGRect.init(x: 0, y: 0, width: image.size.width, height: image.size.height))
        let result = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return result

    }

}

To call the function:

mainCenterIcon.image = UIImage(data: value as! Data)
mainCenterIcon.image = mainCenterIcon.image!.imageByMakingWhiteBackgroundTransparent()

reference: Original Post

score 1 · Answer 2 · answered Dec 18 '20 at 05:28

1

You have to set the image background to clear color and the opaque flag to false.

Use this two:

imageView.backgroudColor = UIColor.clear
imageView.isOpaque = false

answered Dec 18 '20 at 05:28

Massimo Pavanel

754
8
7

This did not work. White background still appears. – husharoonie Dec 18 '20 at 05:36
As far as I know and use every day PNG are natively transparent managed by Xcode. Sometimes happens that some png have some issues that need to force his background in transparent mode. So I think that there is something in your PNG. Take a look on this https://imgur.com/a/CNqFGHP – Massimo Pavanel Dec 18 '20 at 05:50

png transparent image metadata coming with white background

2 Answers2