New Post: Save High Resolution PNG to Disk is very slow

I am really a new user to ImageMagick, please forgive me if a wrote something wrong
I wrote a simple code to convert a 40 Megapixel image from JPEG to PNG, here is the code

            using (MagickImage image = new MagickImage("path/test.jpeg"))
            {
                image.Write("E:/test.png");
            }

These lines of code took 231.959 seconds to execute. I am using the "Magick.NET-7.0.0.0003-Q16-AnyCPU-net40-client" version of ImageMagick.net.
Is there anything wrong with my code? Am I missing something? Or ImageMagick takes this much amount of time for PNG conversion in real?