gm graphicsmagick i don't want to save

im using graphicsmagick for node.js

all i want to do is create graphics server side and spit it out as a png image client side something like:

socket.emit('my_image',{'buffer':buffer});

then i could add 'data:image/png;base64,'+buffer

I have managed to save an image i created with rectangles but saving takes a long time!!

I don't want to save the image as this seems to take ages and i really don't need to keep this image, it just needs to be done server side.

my problem is that i am failing to grasp the correct use of streams/buffers...

gm = require('gm');
require('gm-buffer');

var image=gm(37,37,"#FFF");



for(var r = 0; r < cells.length ; ++r){
    var row = cells[r];
    for(var c = 0; c <= row.length ; ++c){
      var fill= row[c] ? '#000' : '#fff';
      image.drawRectangle((c-num)*num,(r)*num,(c)*num,(r+num)*num).fill(fill)
        //image.buffer(function(err,buf){console.log(buf);});
        //.stream('png')
        //.pipe(writeStream);
        //console.dir(image);
      }}
/*image.toBuffer(function(err,buffer){
    if(err){console.log(err);}else{
      socket.emit('my_image',{'buffer':buffer});
      console.dir(buffer);//<buffer > ???
      }
    });*/


//
//this is all i can get to work but its dead slow (takes nearly 5 minutes!?)
//


image.write('/home/engine/public_html/test.png',function(err){
    if(err){console.log(err);}else{
    //socket.emit('my_image',{'img':image});
    }});