[Swift] iOS Change background color of UIImage

UIImage+withBackground.swift

//
//  UIImage+withBackground.swift
//
//  Created by 홍경표 on 2021/04/12.
//

import UIKit

extension UIImage {
    func withBackground(color: UIColor, opaque: Bool = true) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(size, opaque, scale)
        
        guard let context = UIGraphicsGetCurrentContext(),
              let image = cgImage else { return self }
        
        let rect = CGRect(origin: .zero, size: size)
        context.setFillColor(color.cgColor)
        context.fill(rect)
        context.concatenate(CGAffineTransform(a: 1, b: 0, c: 0, d: -1, tx: 0, ty: size.height))
        context.draw(image, in: rect)
        
        return UIGraphicsGetImageFromCurrentImageContext() ?? self
    }
}