Using Images in Live Activities without exceeding 4kb limit

LiveActivityImage.swift

struct LiveActivityAttributes: ActivityAttributes {
	
	typealias ContentState = LiveActivityState
	
	struct LiveActivityState: Codable, Hashable {
		var activityScore: Int
	}
	
	var activityName: String
	var _image: UIImage?
	weak var image: UIImage? {
		guard let backgroundURL else { return nil }
		return UIImage(contentsOfFile: backgroundURL.relativePath)
	}
	var backgroundURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.willbishop.BigPayloadLiveActivity")?.appending(path: "backgroundImage")
	
	init(activityName: String, image: UIImage? = nil) {
		self.activityName = activityName
		self._image = image
	}

	enum CodingKeys: CodingKey {
		case activityName
	}
	
	func encode(to encoder: Encoder) throws {
		var container = encoder.container(keyedBy: LiveActivityAttributes.CodingKeys.self)
		try container.encode(self.activityName, forKey: .activityName)
		
		//Encoding image to disk separately from Codable encode
		guard let backgroundURL else { return }
		guard let _image else { return }
		guard let ciImage = _image.ciImage ?? CIImage(image: _image) else { return }
		guard let reencodedImageData = UIImage(ciImage: ciImage).jpegData(compressionQuality: 0) else { return }
		try? reencodedImageData.write(to: backgroundURL)
	}
	
	init(from decoder: Decoder) throws {
		let container: KeyedDecodingContainer<LiveActivityAttributes.CodingKeys> = try decoder.container(keyedBy: LiveActivityAttributes.CodingKeys.self)
		self.activityName = try container.decode(String.self, forKey: .activityName)
		//We don't decode the image here as this causes a code 0/1 error in ActivityKit as the size becomes greater than 4kb.
	}
}