Extract Image artwork from MP3 audio data as PNG

Question

I have an image coming in as a JPEG. I need to assign the UIImageView with this data as a png. How can I convert the data to be a PNG by using

.pngData()

My transparent image is showing a white background because it comes in as a JPEG but I need it to come in as a PNG.

@IBOutlet weak var mainCenterIcon: UIImageView!

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
           }
        }

if your intent is to just get the metadata and initialize an UIImage you can check this post https://stackoverflow.com/a/30244852/2303865 — Leo Dabus, Jan 07 '21 at 23:48
I have just checked and the artwork data is indeed a jpeg image — Leo Dabus, Jan 08 '21 at 00:05
Yes, this is my problem with transparent images. How can I convert to PNG when retireving. — husharoonie, Jan 08 '21 at 00:15
Actually there is no JPEG transparent images. I can show you how to extract the artwork (UIImage) from an URL if you would like to — Leo Dabus, Jan 08 '21 at 00:15
Exactly, I have to covert to png because the images showing a background. — husharoonie, Jan 08 '21 at 00:16

Leo Dabus · Accepted Answer · 2021-03-09T20:54:11.093

If you need to convert the artwork data from JPEG to PNG you just need to initialize an UIImage object and get its png data representation. AFAIK there is no way to add transparent background to a JPEG image. Anyway this is how I would convert from JPEG to PNG data:

import MediaPlayer

extension Collection where Element == AVMetadataItem {
    var artwork: UIImage? {
        first { $0.commonKey == .commonKeyArtwork }?.dataValue?.image
    }
}

extension Data {
    var image: UIImage? { UIImage(data: self) }
}

extension AVPlayerItem {
    var artwork: UIImage? { asset.metadata.artwork }
}

extension URL {
    var playerItem: AVPlayerItem { .init(url: self) }
}

let url = Bundle.main.url(forResource: "songName", withExtension: "mp3")!
url.playerItem.artwork // w 600 h 600
if let pngData = url.playerItem.artwork?.pngData() {
    pngData  // 605082 bytes
}

Extract Image artwork from MP3 audio data as PNG

1 Answers1