如何在.NET中使用大位图？

Bitmap bitmap = new Bitmap(10000, 10000);

bitmap.SetPixel(5000, 5000, Color.Red);
Color color = bitmap.GetPixel(5000, 5000);

Bitmap bitmap = new Bitmap(10000, 10000);
Rectangle rect = new Rectangle(0, 0, bitmap.Width, bitmap.Height);
BitmapData bitmapData = bitmap.LockBits(rect, ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb);
int bytesPerPixel = Bitmap.GetPixelFormatSize(PixelFormat.Format32bppArgb) / 8;
int stride = bitmapData.Stride;
IntPtr scan0 = bitmapData.Scan0;
byte[] data = new byte[stride * bitmap.Height];
Marshal.Copy(scan0, data, 0, data.Length);
// 修改像素数据
for (int y = 0; y< bitmap.Height; y++)
{
    for (int x = 0; x< bitmap.Width; x++)
    {
        int index = y * stride + x * bytesPerPixel;
        data[index] = 255; // B
        data[index + 1] = 0; // G
        data[index + 2] = 0; // R
        data[index + 3] = 255; // A
    }
}
// 将修改后的像素数据复制回位图
Marshal.Copy(data, 0, scan0, data.Length);
bitmap.UnlockBits(bitmapData);