Function createCaptchaSync

createCaptchaSync(
    width: number,
    height: number,
    option?: CreateCaptchaOptions,
): CaptchaValueSync

Creates a CAPTCHA image synchronously without async/await requirements.

This function provides the same functionality as createCaptcha() but operates synchronously, making it suitable for use cases where async operations are not desired or possible. Note that background images must be pre-loaded using resolveImage().

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 CaptchaValueSync

Object containing the image buffer and solution text

Example: Basic synchronous generation

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

const { image, text } = createCaptchaSync(300, 100);
fs.writeFileSync('captcha.png', image);
console.log('Solution:', text);

Example: Custom configuration

const { image, text } = createCaptchaSync(400, 150, {
  captcha: {
    text: 'VERIFY',
    size: 55,
    rotate: 20,
    colors: ['#e74c3c', '#f39c12']
  },
  trace: { size: 3, opacity: 0.7 },
  decoy: { total: 30, opacity: 0.25 }
});

Example: With pre-loaded background

import { resolveImage } from 'captcha-canvas';

// Pre-load background image
const background = await resolveImage('./texture.png');

// Generate synchronously
const { image, text } = createCaptchaSync(300, 100, {
  background,
  captcha: { characters: 6, opacity: 0.85 }
});

Example: Non-async context usage

function generateCaptchaForForm() {
  const { image, text } = createCaptchaSync(250, 80, {
    captcha: { characters: 5, size: 35 }
  });
  
  return {
    imageBuffer: image,
    solution: text,
    timestamp: Date.now()
  };
}

Example: Batch generation

function generateMultipleCaptchas(count: number) {
  const captchas = [];
  
  for (let i = 0; i < count; i++) {
    const { image, text } = createCaptchaSync(300, 100);
    captchas.push({ image, text, id: i });
  }
  
  return captchas;
}