Рисовать в пропорции к PictureBox

Я делал как-то так:

    public Bitmap ResizeImage(Image image, Size desireSize)
    {
        var destRect = new Rectangle(0, 0, desireSize.Width, desireSize.Height);
        var destImage = new Bitmap(desireSize.Width, desireSize.Height, PixelFormat.Format32bppPArgb);
        destImage.SetResolution(image.HorizontalResolution, image.VerticalResolution);
        using (var graphics = Graphics.FromImage(destImage))
        {
            graphics.CompositingMode = CompositingMode.SourceCopy;
            graphics.CompositingQuality = CompositingQuality.HighQuality;
            graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
            graphics.SmoothingMode = SmoothingMode.HighQuality;
            graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
            using (var wrapMode = new ImageAttributes())
            {
                wrapMode.SetWrapMode(WrapMode.TileFlipXY);
                graphics.DrawImage(image, destRect, 0, 0, image.Width, image.Height, GraphicsUnit.Pixel, wrapMode);
            }
        }
        return destImage;
    }