using (MemoryStream memoryStream = new MemoryStream())
{
    Image controlImage = new Bitmap(pageImage.Width, pageImage.Height);

    using (Graphics graphics = Graphics.FromImage(controlImage))
    {
        graphics.Clear(Color.White);
        graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
        graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;

        pageImage.DrawToBitmap((Bitmap)controlImage, new Rectangle(0, 0, pageImage.Width, pageImage.Height));
    }

    controlImage.Save(memoryStream, ImageFormat.Png);
    File.WriteAllBytes(originalLocation, memoryStream.ToArray());
}

using (MemoryStream memoryStream = new MemoryStream())
{
    Image controlImage = new Bitmap(pageImage.Width, pageImage.Height);

    using (Graphics graphics = Graphics.FromImage(controlImage))
    {
        graphics.Clear(Color.White);
        graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
        graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;

        pageImage.DrawToBitmap((Bitmap)controlImage, new Rectangle(0, 0, pageImage.Width, pageImage.Height));
    }

    controlImage.Save(memoryStream, ImageFormat.Png);
    File.WriteAllBytes(originalLocation, memoryStream.ToArray());
}

private void PageImage_MouseUp(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        isDrawing = false;

        //MemoryStream ms = new MemoryStream();
        pageImage.Image?.Dispose();
        drawingBitmap.Save("C:\\test.png"); //pageImage.ImageLocation);

        
    }
}

private void PageImage_MouseUp(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        isDrawing = false;

        //MemoryStream ms = new MemoryStream();
        pageImage.Image?.Dispose();
        drawingBitmap.Save("C:\\test.png"); //pageImage.ImageLocation);

        
    }
}