UIImage+ResizeCanvas.swift

import UIKit

extension UIImage {
    func resizeCanvas(size canvasSize: CGSize, color canvasColor: UIColor = .clear) -> UIImage {
        let renderer = UIGraphicsImageRenderer(size: canvasSize)
        
        let resizedImage = renderer.image { (context) in
            canvasColor.setFill()
            context.fill(CGRect(origin: .zero, size: canvasSize))
            
            let selfOrigin = CGPoint(
                x: (context.format.bounds.width - self.size.width) / 2,
                y: (context.format.bounds.height - self.size.height) / 2
            )
            self.draw(at: selfOrigin)
        }
        
        return resizedImage
    }
}