php streams - generating the http header

Hi everyone, Back Again :). I tried searching around, but all in vain. My question is that how do i use the php stream to generate my custom header and then write to it the corresponding file? I could get that php_stream *stream need to be created and then php_stream_write needs to be used to write to it. But how do I open the stream? Basically I want to write a file to the browser, say a .png file from my extension. I can not use the header() function of php. And even if i use it, how do i send the png file to the browser. I would prefer not using the header() funcion and write my own header. Any pointers please? Thanking you in advance. Regards, aj http://arjun.notlong.com