captchapng

A numeric captcha generator for Node.js

Features

• Only generate numeric captcha PNG image
• Build-in fonts
• Characters up and down, left and right limits, random displacement
• Full JavaScript

Examples

/**
 * Captcha PNG img generator
 * @Author: George Chan
 * @Email: gchan@21cn.com
 * @Version: 1.0
 * @Date: 2013-08-18
 * @license http://www.opensource.org/licenses/bsd-license.php BSD License
 */

var http = require('http');
var captchapng = require('captchapng');

http.createServer(function (request, response) {
    if(request.url == '/captcha.png') {
        var p = new captchapng(80,30,parseInt(Math.random()*9000+1000)); // width,height,numeric captcha
        p.color(0, 0, 0, 0);  // First color: background (red, green, blue, alpha)
        p.color(80, 80, 80, 255); // Second color: paint (red, green, blue, alpha)

        var img = p.getBase64();
        var imgbase64 = new Buffer(img,'base64');
        response.writeHead(200, {
            'Content-Type': 'image/png'
        });
        response.end(imgbase64);
    } else response.end('');
}).listen(8181);

console.log('Web server started.\n http:\\127.0.0.1:8181\captcha.png');