Trabajar con imagenes en .net C#

public byte[] ImageArray(Image objImage)
{
string sTempFile = Path.GetTempFileName();
FileStream fileStream = new FileStream(sTempFile, FileMode.OpenOrCreate, FileAccess.ReadWrite);
objImage.Save(fileStream, System.Drawing.Imaging.ImageFormat.Png);
fileStream.Position = 0;
int _Length = Convert.ToInt32(fileStream.Length);
byte[] bytes = new byte[_Length];
fileStream.Read(bytes, 0, _Length);
fileStream.Close();
return bytes;
}
public Image GetImage(byte[] byteArray)
{
if (byteArray == null) return null;
MemoryStream memoryStream = new MemoryStream(byteArray);
Bitmap _bitmap = null;
try
{
_bitmap = new Bitmap(memoryStream);
}
catch (Exception ex)
{
new ArgumentException(ex.Message);
}
return _bitmap;
}