c#Bitmap byte[]Streamファイル相互変換

//byte[]  
public static Bitmap BytesToBitmap(byte[] Bytes)
        {
            MemoryStream stream = null;
            try
            {
                stream = new MemoryStream(Bytes);
                return new Bitmap((Image)new Bitmap(stream));
            }
            catch (ArgumentNullException ex)
            {
                throw ex;
            }
            catch (ArgumentException ex)
            {
                throw ex;
            }
            finally
            {
                stream.Close();
            }
        } 

// byte[] 
        public static byte[] BitmapToBytes(Bitmap Bitmap)
        {
            MemoryStream ms = null;
            try
            {
                ms = new MemoryStream();
                Bitmap.Save(ms, Bitmap.RawFormat);
                byte[] byteImage = new Byte[ms.Length];
                byteImage = ms.ToArray();
                return byteImage;
            }
            catch (ArgumentNullException ex)
            {
                throw ex;
            }
            finally
            {
                ms.Close();
            }
        }
    }

=====================

* Stream   byte[]  
 * - - - - - - - - - - - - - - - - - - - - - - - */
/// <summary>
///   Stream   byte[]
/// </summary>
public byte[] StreamToBytes(Stream stream)
{
    byte[] bytes = new byte[stream.Length];
    stream.Read(bytes, 0, bytes.Length);

    //  
    stream.Seek(0, SeekOrigin.Begin);
    return bytes;
}

/// <summary>
///   byte[]   Stream
/// </summary>
public Stream BytesToStream(byte[] bytes)
{
    Stream stream = new MemoryStream(bytes);
    return stream;
}


/* - - - - - - - - - - - - - - - - - - - - - - - - 
 * Stream    
 * - - - - - - - - - - - - - - - - - - - - - - - */
/// <summary>
///   Stream  
/// </summary>
public void StreamToFile(Stream stream,string fileName)
{
    //   Stream   byte[]
    byte[] bytes = new byte[stream.Length];
    stream.Read(bytes, 0, bytes.Length);
    //  
    stream.Seek(0, SeekOrigin.Begin);

    //   byte[]  
    FileStream fs = new FileStream(fileName, FileMode.Create);
    BinaryWriter bw = new BinaryWriter(fs);
    bw.Write(bytes);
    bw.Close();
    fs.Close();
}

/// <summary>
///   Stream
/// </summary>
public Stream FileToStream(string fileName)
{            
    //  
    FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);
    //   byte[]
    byte[] bytes = new byte[fileStream.Length];
    fileStream.Read(bytes, 0, bytes.Length);
    fileStream.Close();
    //   byte[]   Stream
    Stream stream = new MemoryStream(bytes);
    return stream;
}