Function createCaptcha

createCaptcha(
    width: number,
    height: number,
    option?: CreateCaptchaOptions,
): CaptchaValue

Creates a CAPTCHA image asynchronously with automatic security features.

This is the simplest way to generate a CAPTCHA with sensible defaults and automatic security features including decoy characters, trace lines, and random text generation. The function handles the complete generation process and returns both the image and solution.

Parameters

width: number
Width of the CAPTCHA image in pixels
height: number
Height of the CAPTCHA image in pixels
option: CreateCaptchaOptions = {}
Optional configuration for customizing CAPTCHA appearance and security

Returns CaptchaValue

Object containing the image promise and solution text

Example: Quick CAPTCHA generation

import { createCaptcha } from 'captcha-canvas';
import fs from 'fs';

const { image, text } = createCaptcha(300, 100);
const buffer = await image;

fs.writeFileSync('captcha.png', buffer);
console.log('Solution:', text);

Example: Custom text and styling

const { image, text } = createCaptcha(400, 150, {
  captcha: {
    text: 'HELLO',
    size: 60,
    colors: ['#e74c3c', '#3498db', '#27ae60']
  }
});

Example: Enhanced security configuration

const { image, text } = createCaptcha(350, 120, {
  captcha: { characters: 8, size: 45 },
  trace: { color: '#95a5a6', size: 4, opacity: 0.8 },
  decoy: { total: 50, opacity: 0.3, size: 18 }
});

Example: With background image

import { resolveImage } from 'captcha-canvas';

const background = await resolveImage('./noise-pattern.jpg');
const { image, text } = createCaptcha(300, 100, {
  background,
  captcha: { opacity: 0.9 } // Make text more visible over background
});

Example: Web server integration

app.get('/captcha', async (req, res) => {
  const { image, text } = createCaptcha(300, 100);
  
  // Store solution in session for verification
  req.session.captchaSolution = text;
  
  const buffer = await image;
  res.type('png').send(buffer);
});