调整图像大小，同时保持纵横比

大家好，我从互联网上下载了一张图像，需要将其大小调整为其大小的 1/4，同时保留其纵横比。关于如何最简单地做到这一点有什么想法吗？

WebRequest requestPic = WebRequest.Create(imageURL);
WebResponse responsePic = requestPic.GetResponse();
Image webImage = Image.FromStream(responsePic.GetResponseStream());

// Need to resize image here

Random rand = new Random();
string imageName = string.Format("{0:x}{1:x}", DateTime.Now.Ticks, rand.Next(0, 60400000));
if (webImage != null)
{
     webImage.Save(string.Format("c:\\{0}.jpg", imageName));
}

谢谢你！

Image thumb = image.GetThumbnailImage(image.Width / 2, image.Height / 2, null, IntPtr.Zero);
image.Dispose();