# Cap Server

A simple server to manage a collection of bottle caps, including their names, images, and a classifier to recognize them by image.
Works together with the companion app [Caps-iOS](https://christophhagen.de/git/ch/Caps-iOS).
A description of the project is provided [on my website](https://christophhagen.de/projects/software/caps/en.html).

## Overview

The server maintains the cap database of all bottle caps that I've collected so far, and allows me to add new caps, images and classifiers using the associated [iOS App](https://christophhagen.de/git/ch/Caps-iOS).

It currently has the following functions:
- Provide the data (name, id, image count, ...) for all existing caps
- Serve a representative image for each cap, and maintain the image catalog for classifier training
- Add new caps through the iOS App
- Add new images through the app
- Rename caps and change the main image
- Protect the database from changes through token-based authentication
- Host a classifier model to download for offline cap classification
- Upload new classifiers when trained on a different system using CreateML
- Provide a script to train a new classifier on the current image set
- Provide an HTML snippet which can be embedded in a website to show the current cap count ([see here](https://christophhagen.de/projects/software/caps/en.html))
- Provide a webpage showing a grid of all caps, where mosaic images can be created.

## Configuration

The server is configured using a configuration file `config.json` located in the `Resources` folder:

```json
{
    "port" : 6001,
    "maxBodySize" : "2mb",
    "logPath": "\/var\/log\/caps.log",
    "serveFiles": true,
    "writers" : [
        "auth_key_1"
    ]
}
```

The `writers` array contains a list of strings acting as access tokens to restrict operations where data is mutated (adding images, changing information, updating the classifier).

## Mosaic

The server provides a simple web page where visitors can arrange the existing bottle caps in a grid, to create mosaic images from the caps.
It allows loading and saving arrangements locally, and has the option to display the average color of the caps.

You can try it [here](https://christophhagen.de/caps/grid.html).

Note: The data for the mosaic is currently not updated automatically, since Swift on Linux has no built-in tools to create JPGs. The thumbnails are created when a new classifier is trained.

## Classifier training

The main server is running on Linux, which doesn't provide the CreateML framework required for classifier training. 
This has to be done on macOS using the [Caps-Train](https://christophhagen.de/git/ch/Caps-Train) repository.

## Future work
- Create thumbnails on the server using [JPEG](https://github.com/kelvin13/jpeg)