WPFイメージコントロールSource:Byte[],BitmapImage相互変換

FileStream fs = new FileStream(filepath, FileMode.Open, FileAccess.Read);
byte[] desBytes = new byte[fs.Length];
fs.Read(desBytes, 0, desBytes.Length);
fs.Close();  

public static BitmapImage ByteArrayToBitmapImage(byte[] byteArray) 
{ 
    BitmapImage bmp = null;  
    try 
    { 
        bmp = new BitmapImage(); 
        bmp.BeginInit(); 
        bmp.StreamSource = new MemoryStream(byteArray); 
        bmp.EndInit(); 
    } 
    catch 
    { 
        bmp = null; 
    }  
    return bmp; 
}

public static byte[] BitmapImageToByteArray(BitmapImage bmp) 
{ 
    byte[] byteArray = null;  
    try 
    { 
        Stream sMarket = bmp.StreamSource;  
        if (sMarket != null && sMarket.Length > 0) 
        { 
            // ， Position Stream ， 0。 
            sMarket.Position = 0; 

            using (BinaryReader br = new BinaryReader(sMarket)) 
            { 
                byteArray = br.ReadBytes((int)sMarket.Length); 
            } 
        } 
    } 
    catch 
    { 
        //other exception handling 
    }  
    return byteArray; 
}

WriteableBitmap wb = new WriteableBitmap(img.Source as BitmapSource);// Image WriteableBitmap 
byte[] b = Convert.FromBase64String(GetBase64Image(wb));// byte