# AudioImage

AudioImage is a powerful web-based tool for Audio Spectrogram Art and Digital Steganography, powered by a Flask backend and Svelte 5 frontend. It transforms audio into visual art and allows for secure, invisible file embedding.

## Features

*   **Process Visualizer**: A real-time, interactive visualization page that lets you watch and hear the transformation process. 
    *   **Live Waveform**: See the audio signal rendered as a glowing, real-time oscilloscope.
    *   **Step-by-Step Reveal**: Watch the spectrogram and steganographic image being constructed layer by layer.
*   **Audio Art Generation**: Convert MP3/AAC audio files into high-resolution visual spectrograms using Python's `librosa` and `matplotlib`.
    *   **GPU Acceleration**: Automatically uses `torchaudio` and CUDA if available for lightning-fast processing.
*   **Steganography Hider**: Hide secret audio or image files inside a "host" PNG image effectively using LSB (Least Significant Bit) encoding.
*   **Universal Decoder**: Decode any image created with AudioImage to retrieve the original hidden files.
*   **Secure & Private**: All processing happens locally on your server; files are cleaned up automatically.

## Requirements

*   Python 3.12+
*   Node.js & npm (or Bun)
*   CUDA-enabled GPU (optional, for faster spectrogram generation)

## Installation

1.  **Backend Setup**:
    ```bash
    cd server
    python3 -m venv venv
    source venv/bin/activate
    pip install -r requirements.txt
    ```

    *Optional for GPU support:*
    ```bash
    pip install torch torchaudio --index-url https://download.pytorch.org/whl/cu118
    ```
    *(Adjust CUDA version as needed)*

2.  **Frontend Setup**:
    ```bash
    # Root directory
    npm install
    npm run build
    ```

## Running the Application

1.  Start the Flask server (which serves the frontend):
    ```bash
    cd server
    source venv/bin/activate
    python app.py
    ```
2.  Open your browser to `http://127.0.0.1:5000`.

## Architecture

*   **Frontend**: SvelteKit (SPA mode), Svelte 5 Runes, TailwindCSS.
    *   Uses **Server-Sent Events (SSE)** for real-time progress streaming.
    *   **Canvas API** & **Web Audio API** for the visualizer.
*   **Backend**: Flask, NumPy, PIL, Librosa, PyTorch (optional).
*   **Integration**: Flask serves the static Svelte build for a unified deployment experience.

## Usage Notes

*   **Supported Audio**: MP3, AAC, WAV, FLAC.
*   **Supported Images**: PNG (host/stego).
*   **Visualizer**: Visit the `/visualizer` page or click the link in the header to see the magic happen in real-time.