Unable to upload picture when sending as Base64 String

I am trying to send an image to our asp.net webservice from android.Here is my sample code :

// Getting image from Gallery

Uri selectedImage = data.getData();
String[] filePathColumn = { MediaStore.Images.Media.DATA };

Cursor cursor = getContentResolver().query(selectedImage,
filePathColumn, null, null, null);
cursor.moveToFirst();

int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
picturePath = cursor.getString(columnIndex);

cursor.close();

/* BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 4;*/

thumbnail = (BitmapFactory.decodeFile(picturePath));
img_photo.setImageBitmap(thumbnail);



// converting imag into base64 string

img_photo.buildDrawingCache();
Bitmap bm = img_photo.getDrawingCache();

ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.PNG, 100, baos); // bm is the bitmap

byte[] photo = baos.toByteArray();
System.out.println("this is byte array" + bytearray);

String temp_base =Base64.encodeToString(photo,Base64.NO_WRAP);

// calling webservice

SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);

request.addProperty("CarID", SellCarDetailView.sellcardetails_carid);
request.addProperty("pic",temp_base);
System.out.println("this is piccontent" +temp_base);
try {

SoapSerializationEnvelope soapEnvelope = new SoapSerializationEnvelope(
SoapEnvelope.VER11);
soapEnvelope.encodingStyle = SoapEnvelope.ENC;
// new MarshalBase64().register(soapEnvelope);
soapEnvelope.dotNet = true;
soapEnvelope.setOutputSoapObject(request);
HttpTransportSE aht = new HttpTransportSE(URL);
//AndroidHttpTransport aht = new AndroidHttpTransport(URL);
aht.call(SOAP_ACTION, soapEnvelope);

// SoapObject response = (SoapObject)envelope.getResponse();
SoapPrimitive response = (SoapPrimitive) soapEnvelope.getResponse();
String temp3 = response.toString();

Log.v("TAG", temp3);

} catch (Exception e) {
e.printStackTrace();
}


How ever i am getting "invalid parameter" at web service end.

// Asp.net code

[ScriptMethod(UseHttpGet = false, ResponseFormat = ResponseFormat.Xml)]
[WebMethod(EnableSession = true)]
public string UploadPictureByCarIDFromAndroid(string CarID, string make, string model, string year, string UserID, string pic, string AuthenticationID, string CustomerID, string SessionID)
{

string bStatus = "Failed";
MobileBL objMobile = new MobileBL();
UsedCarsInfo objCarPicInfo = new UsedCarsInfo();

try
{
try
{
if (AuthenticationID == ConfigurationManager.AppSettings["AppleID"].ToString())
{
objCarPicInfo.Carid = Convert.ToInt32(CarID);
byte[] picContent = Convert.FromBase64String(pic);
// byte[] picContent = Base64.decode(pic);
MemoryStream ms = new MemoryStream(picContent, 0,picContent.Length); // getting "invalid length"
ms.Write(picContent, 0, picContent.Length);
Bitmap oBitmap1 = new Bitmap(ms);// getting "invalid length" error here
// System.Drawing.Image image = System.Drawing.Image.FromStream(ms, true);




}
}
catch (Exception ex)
{

}

}
catch (Exception ex)
{
}


return bStatus;
}