The IResponse::BinaryWrite method writes data to the HTTP output without converting Unicode characters to ANSI. For more information, see the BinaryWrite method of the Response object.
HRESULT BinaryWrite(
VARIANT varBuffer //VARIANT containing the data as a SAFEARRAY
);
This method writes the specified information to the current HTTP output without any character conversion. This method is useful for writing nonstring information, such as binary data, required by a custom application.