int i = 0;
foreach (var item in list)
{
    Bitmap bmp = new Bitmap(32, 32);
    BitmapData bData = bmp.LockBits(new Rectangle(new Point(), bmp.Size), ImageLockMode.WriteOnly,
        PixelFormat.Format1bppIndexed);
    Marshal.Copy(item.bytes, 0, bData.Scan0, item.bytes.Length);
    bmp.UnlockBits(bData);
    i++;
    bmp.Save("C:\rr\r" + i + ".bmp");
    bmp.Dispose();
}