C# Bitmap to ByteArray representation

[mmahoi]

Hi there,

I wanted to change the monochrome bitmap to byte array and send the pixel data to the serial thermal printer.

When i convert the bitmap to byte array, the first two byte i get is 13780 instead of 19778 (representation of BM as per bitmap specs). I used the following code as reference:
ImageData = ConvertImageToByteArray(bmp,System.Drawing.Imaging .ImageFormat.Png);

private static byte[] ConvertImageToByteArray(System.Drawing.Image imageToConvert,ImageFormat formatOfImage)
{
byte[] Ret;
using (MemoryStream ms = new MemoryStream())
{
imageToConvert.Save(ms,formatOfImage);
Ret = ms.ToArray();
}
return Ret;
}


if i call the above function as below
ImageData = ConvertImageToByteArray(bmp,System.Drawing.Imaging .ImageFormat.<b>Bmp</b>);
then all the byteArray is filled with 0;

What am i doing wrong? Or is there any other approach for doing this? Any solution and suggestion will be appreciated.