boona13

boona13 / image-extender

Public

Seamlessly extend any image in any direction with AI. Open-source web app powered by Gemini via OpenRouter, with Poisson-blended seams and best-of-3 variant picker.

github.comboona13image-extender ai gemini image-generation nano-banana nextjs
17
6
89% credibility
Found May 30, 2026 at 17 stars -- GitGems finds repos before they trend. Get early access to the next one.
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AI Analysis
TypeScript
AI Summary

Image Extender is a free, browser-based creative studio that uses AI to help game developers create complete 2D art sets. It can extend any image in any direction using smart blending, and it includes four specialized workspaces for building parallax backgrounds, seamless tile textures, character sprite animations, and decoration props. Everything stays consistent across an entire project because the AI shares a common scene brief across all assets. Users bring their own AI service key (stored only in their browser), and all processing happens through a simple server proxy. The app exports game-ready files in formats compatible with popular engines like Unity, Godot, and Phaser.

How It Works

1
💡 Discover the tool

You hear about a free web tool that can extend any image in any direction using AI — and it also builds complete game art sets from the same studio.

2
🖼️ Open the app in your browser

You visit the website, and it opens as a clean creative studio. On first visit, it asks for an AI service key — you get one for free from openrouter.ai, paste it in once, and it's stored safely in your browser forever.

3
🎨 Choose your creative mode

You pick from five workspaces: Extender (outpaint any image), Parallax (build scrolling backgrounds), Tiles (create seamless platformer textures), Sprites (animate characters), or Props (design decorations).

4
Work on any asset type
🏔️
Build parallax backgrounds

Create multi-layer scrolling scenes with Sky, Far, Mid, and Near layers. Preview them moving at different speeds, auto-extend to your target width, and export everything as a ZIP ready for your game engine.

🧱
Generate tile sets

Describe a material like mossy stone or red brick, and the AI creates all 13 tiles (body, edges, corners) in one pass so everything matches perfectly. Preview how they fit together, then export.

🧍
Animate a character

Describe your character once, lock in the look, then generate walk, run, jump, attack, and more — all in one consistent style. Play back the animation and export sprite sheets.

🌿
Design decorations

Build an endless library of transparent props like rocks, mushrooms, and plants. Each batch adds 8 new items that match your existing style.

5
✨ Refine with AI feedback

For tiles and sprites, an AI reviewer checks your work and tells you if anything needs fixing — then you regenerate just what needs adjusting, keeping everything else intact.

6
📦 Export for your game engine

Download individual images, packed atlases, or ZIP bundles with manifest files — everything organized and ready to drop straight into Unity, Godot, Phaser, or Tiled.

🎮 Your game art is ready

You have a complete set of matching assets — backgrounds, tiles, characters, and decorations — all built from the same creative vision, ready to build your game.

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AI-Generated Review

What is image-extender?

Image-extender is an open-source web app that uses AI to seamlessly extend images in any direction. Built with Next.js and TypeScript, it connects to Google's Gemini models through OpenRouter to generate new image content that blends invisibly with the original using Poisson image editing. Beyond basic outpainting, the app ships as a mini game-art studio with dedicated workspaces for parallax backgrounds, 2D platformer tile sets, character sprite animations, and decoration props.

Why is it gaining traction?

The core outpainting tool stands out with its best-of-3 variant picker and mathematically invisible seams, letting you extend a 1024x1024 portrait into a cinematic wide shot in a few clicks. Game developers are drawn to the specialized pipelines: generate a complete 13-tile autotile set in one AI call, produce 8-frame sprite animations with a two-pass anchor-to-sheet workflow, or build infinite parallax backgrounds with auto-extend and tileable loop healing. The BYOK model means no accounts or logins, just paste your OpenRouter key once and go.

Who should use this?

Indie game developers building 2D platformers will get the most value from the tile, sprite, and parallax studios. Photographers and designers who need to expand images beyond their original framing will appreciate the straightforward click-to-extend workflow and art style presets. Anyone experimenting with AI outpainting will find it a useful free alternative to closed platforms, provided they're comfortable providing their own API key.

Verdict

This is a genuinely useful tool with thoughtful engineering behind its game-art pipelines, but with only 17 stars and a 0.9% credibility score, it's early-stage software with limited community validation. Worth trying for the specific use cases it targets, but don't bet a production workflow on it without testing thoroughly first.

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