# twotwothree

**Converts 2D images into 3D-looking, stylized shaded images (anime / cel-shaded presets).**

---

## Overview

`twotwothree` is a small Rust command-line tool that analyzes an input image to compute a depth map, normals, edges, and ambient occlusion, then applies stylized shading to produce a 3D-looking output image. It ships with an **anime** preset for quick stylized results and also exposes parameters to tune depth and shading.

Built with: **Rust**, `image`, `nalgebra`, `clap`, `anyhow`.

---

## Quickstart

Build (release recommended):

```bash
cargo build --release
```

Run CLI (example):

```bash
cargo run --release -- input.png output.png
```

After a successful run you'll see:

> Saved: ./out/output.png

### Web Server & UI

Run the HTTP server:

```bash
cargo run --bin server --release
```

Then open **http://localhost:3000/demos/223/** in your browser:
- **Upload**: Convert images with adjustable anime preset, depth scale, and gamma
- **Gallery**: Browse publicly shared conversions
- **Contact**: Find contact info and GitHub link
- **Dark Mode**: Toggle light/dark theme (persisted in localStorage)

---

## Usage

Basic CLI:

```text
Usage: twotwothree <INPUT> <OUTPUT> [OPTIONS]

Args:
  <INPUT>    Input image file (png, jpeg, ...)
  <OUTPUT>   Output image file (png recommended)

Options:
  --anime <bool>          Anime preset (default: true)
  --depth-scale <float>   Depth scale modifier (used when --anime=false, default: 1.0)
  --depth-gamma <float>   Depth gamma (used when --anime=false, default: 1.0)
  -h, --help              Print help information
  -V, --version           Print version
```

Notes:
- The `--anime` preset chooses conservative depth/gamma values for a stylized look. To customize depth values, disable the preset with `--no-anime` or `--anime false` and pass `--depth-scale` / `--depth-gamma`.

Example (disable anime and increase depth):

```bash
cargo run --release -- input.png output.png --no-anime --depth-scale 1.5 --depth-gamma 1.2
```

---

## Examples & Tips

- Use high-resolution inputs for better detail in the computed depth map.
- The tool writes a PNG (and other formats supported by the `image` crate) to the specified output path.
- The algorithm applies shading, rim lighting, ambient occlusion, edge enhancement, and optional cel shading — tweak parameters in code if you want custom effects.

---

## Internals

- `compute_depth_map` converts pixel brightness (and alpha) into a depth buffer, with optional "bulge" toward the image center to suggest camera projection.
- `compute_normals`, `compute_edge_strength`, and `compute_ambient_occlusion` prepare shading data.
- `apply_shading` composes ambient, diffuse, specular, rim effects, saturation and bloom to produce the final color.

---

## Roadmap

- Improve performance (parallelize more work / optimize memory).
- Add unit/integration tests and example-based visual tests.
- Add API documentation for `/api/convert` and `/api/upload` endpoints.

---

## License

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

---