Local image placeholder service

app.js

// Local image placeholder service
// Usage: <img src="http://localhost:9999/300/400" /> 

var express = require('express'),
    app = express(),
    gm = require('gm');

app.get('/:width/:height', function(request, response){
  var width = request.params.width,
    height = request.params.height,
    fontSize = Math.min( Math.min(width, height) / 4.0, width / 6 ),
    dimensionText = width + " x " + height; 

  gm(width, height, "#157ad3")
    .fontSize(fontSize)
    .fill("#fff")
    .drawText(0, 0, dimensionText, "Center")
    .stream('png')
    .pipe(response);
});

var server = app.listen(9999);