在c#.net中如何在不降低图像质量的情况下调整图像大小？

using System.Drawing;

public Image ResizeImage(Image originalImage, int newWidth, int newHeight)
{
    // 创建一个新的Bitmap对象，并设置宽度和高度
    Bitmap resizedImage = new Bitmap(newWidth, newHeight);

    // 创建一个Graphics对象，用于绘制调整大小后的图像
    using (Graphics graphics = Graphics.FromImage(resizedImage))
    {
        // 设置绘制质量，以保持图像质量不变
        graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
        graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
        graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;

        // 绘制调整大小后的图像
        graphics.DrawImage(originalImage, 0, 0, newWidth, newHeight);
    }

    return resizedImage;
}

Image originalImage = Image.FromFile("原始图像路径");
int newWidth = 800;
int newHeight = 600;

Image resizedImage = ResizeImage(originalImage, newWidth, newHeight);

// 保存调整大小后的图像
resizedImage.Save("调整大小后的图像路径");