static void Main(string[] args)
{
byte[] imageData = { 255, 0, 0, 255 };
int size = Marshal.SizeOf(imageData[0]) * imageData.Length;
IntPtr mem = Marshal.AllocHGlobal(size);
Marshal.Copy(imageData,0,mem,4);
Bitmap bmp = new Bitmap(1, 1,0, PixelFormat.Format32bppPArgb,mem);
Marshal.FreeHGlobal(mem);
}