🔌 Image2CPP — Arduino / ESP32 Image Converter

Convert images to C++ byte arrays for OLED, e-paper, and TFT displays — 100% in your browser.

A maker-first image-to-C++ converter built for embedded developers. Drop in any PNG/JPG/BMP, choose your display (SSD1306 OLED, Waveshare e-paper, ILI9341 TFT, and more), tune dithering in real time, and copy a ready-to-paste PROGMEM byte array straight into your Arduino, ESP32, STM32, or Raspberry Pi Pico sketch. Everything runs locally — no uploads, no tracking, no limits.

Try it live at pixel.hjlabs.in — no signup, free forever.

🚀 Live Demo · ✨ Features · 🛠 Installation · 📐 Architecture · 💡 Use Cases · 📬 Contact

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🎯 What is this?

Embedded developers working with 128x64 SSD1306 OLEDs or e-paper displays face the same problem every time: "how do I turn this logo PNG into a const uint8_t PROGMEM array that my microcontroller can draw?"

Image2CPP solves it. Drop an image, pick your display spec and orientation, preview the 1-bit dithered output in real time, and copy the generated C/C++ array straight into your sketch. Because it's fully client-side, you can use it on sensitive design files without worrying about them leaving your machine.

The fastest way to get a logo, icon, or splash screen onto a 128x64 OLED — from drag-and-drop to working sketch in 30 seconds.

📸 Screenshot

✨ Features

📟 Display Presets SSD1306 OLED (128x32, 128x64) SH1106 OLED Waveshare e-paper (various sizes) ILI9341 TFT (240x320) ST7789 TFT Generic monochrome / 16-bit RGB565	🎛 Dithering Algorithms Floyd–Steinberg Atkinson Bayer (ordered) Threshold (pure 1-bit) Live preview as you adjust Invert, rotate, scale, crop
💻 Output Formats Arduino PROGMEM byte array Plain C const uint8_t[] Adafruit GFX compatible U8g2 bitmap format RGB565 16-bit for colour TFTs Horizontal / vertical byte orientation	🔒 100% Client-Side No image ever uploaded Works completely offline No tracking, no ads MIT licensed, self-hostable Fast on slow internet / field work

💡 Use Cases

Use Case	Description
Building an ESP32 smart-home dashboard	Convert weather icons and app logos for a 128x64 OLED status screen
Designing a custom Arduino badge / wearable	Rapidly iterate on splash-screen art and see dithering live
Waveshare e-paper projects	Generate 1-bit assets with proper dithering for crisp e-ink rendering
Retro handhelds & PICO-8 style devices	Turn pixel art into ready-to-use C arrays for ILI9341 / ST7789 TFTs
Hackathon prototypes	Skip the toolchain wrestling — just drag, drop, copy, compile

📐 Architecture

┌────────────────────────────────────────┐
│            User's Browser               │
│  ┌─────────────────────────────────┐   │
│  │  Canvas API — image decode      │   │
│  │  Dithering algorithms (JS)      │   │
│  │  Byte-array serializer          │   │
│  └─────────────────────────────────┘   │
└──────────────────┬─────────────────────┘
                   │ Only HTML/CSS/JS served
┌──────────────────▼─────────────────────┐
│        Cloudflare Workers               │
│  ┌─────────────────────────────────┐   │
│  │  Static asset serving (edge)    │   │
│  │  Pageview counter (D1)          │   │
│  └─────────────────────────────────┘   │
└────────────────────────────────────────┘

Tech Stack:

• Runtime: Cloudflare Workers (serves the static bundle at the edge)
• Language: Vanilla JavaScript — no framework, no build step
• Image processing: HTML <canvas> + pure-JS dithering implementations
• Storage: Cloudflare D1 for anonymous pageview analytics only
• Privacy: No image ever leaves the browser, not even to the Worker

🛠 Installation

Prerequisites

• Node.js 18+
• Cloudflare account (free tier works)
• wrangler CLI: npm install -g wrangler

Quick Start

# Clone the repository
git clone https://github.com/hemangjoshi37a/hjlabs.in-image2cpp.git
cd hjlabs.in-image2cpp

# Install dependencies
npm install

# Login to Cloudflare
npx wrangler login

# Run locally
npx wrangler dev

# Deploy to your Cloudflare account
npx wrangler deploy

Environment Setup

1. (Optional) Create a D1 database for pageview stats: npx wrangler d1 create hjlabs-analytics
2. Update wrangler.toml with your Cloudflare account details
3. Point a subdomain CNAME at your deployed Worker

🌐 Part of the hjLabs.in Ecosystem

This is one of 5 free open-source micro-SaaS products in the hjLabs.in ecosystem:

Product	URL	Description
🎨 OG Generator	og.hjlabs.in	Favicon & Open Graph image generator
🛠 JSON Formatter	fmt.hjlabs.in	15 free developer tools (JSON, JWT, Base64, etc)
🖼 Image Enhancer	enhance.hjlabs.in	AI photo enhancer + marketing image generator
⚖️ DPDPA Compliance	compliance.hjlabs.in	India DPDPA 2023 privacy policy generator
🔌 Image2CPP	pixel.hjlabs.in	Convert images to C++ arrays for Arduino/ESP32

Plus the hjLabs.in AI/ML Services consulting site for AI/ML solutions for industrial automation, IoT, and SEO.

🤝 Contributing

Contributions are welcome! Found a bug or have a feature idea? Please open an issue or PR.

1. Fork the repo
2. Create a feature branch (git checkout -b feature/amazing)
3. Commit your changes
4. Push to the branch
5. Open a Pull Request

📄 License

This project is licensed under the MIT License — see the LICENSE file for details.

You're free to use, modify, distribute, and even sell this project. Attribution appreciated but not required.

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📬 Contact

Hemang Joshi — Founder, hjLabs.in

hjLabs.in — Industrial Automation | AI/ML | IoT | SEO Tools

Serving 15+ countries with a 4.9⭐ Google rating

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