spacemudd / webagent-scanner

An open source Web Agent to aid web applications to utilize scanners via TWAIN

What is it about?

Allows your web application to communicate with a scanner and receive scanned images.

Installation

1. Make sure you have Python 2.7 is installed.
2. Make sure cmd pip is recognized, else, add Python to your system's PATH.
3. Download & install the TWAIN python module.
4. Execute pip install image (responsible for serving images)
5. Execute pip install tornado (responsible for opening a web server)
6. Execute pip install wxPython (responsible for the app to become a tray icon)
7. Navigate to the project folder and execute app.py.

Usage

1. In command prompt, navigate to the project's root and run app.py.

2. Make sure app.py is serving.

3. In your web application(s), call a simple Ajax GET request to localhost:8087 (see below section).

API

All communicaction are in HTTPS GET requests format.

/scan

Description

Selects the first scanner the app finds and begins the scanning call.

Request example

$.support.cors = true;

$.ajax({
    crossDomain: true,
    type : "GET",
    url : "https://localhost:8087/scan",
    dataType : "json",
    success : function(response) {
        console.log(response.data) // base64 encoded image
    },
});

Response example

String. Base64 encoded string of a single JPEG image.

/multi-scan

Description

Selects the first scanner the app finds and begin scanning until all papers are scanned.

Request example

$.support.cors = true;

$.ajax({
    crossDomain: true,
    type : "GET",
    url : "https://localhost:8087/multi-scan",
    success : function(response) {
        console.log(response.data.images); // An array of base64 encoded strings.
        console.log('total:' + response.data.total); // Total images scanned.
    },
});

Example response

{
    'images': {
        base64 encoded string,
        base64 encoded string,
        ...
    },
    'total': 10
}

/get-scanners

Description

Gets a list of scanners detected.

Request example

{
    'scanner-name': 'scanner-name',
    'scanner-name1': 'scanner-name1',
    ...
}

How to build

1. Run python setup.py py2exe
2. Once compiled, navigate to dist, and open app.exe.

If you plan to take app.exe somewhere else, it must have the folder 'cert' next to it with the certificate files.

Questions

1. How do I set the scanner?

In app.py, you will find the function setScanner, use that.

2. Can I see a list of the scanners connected?

Call the route /get-scanners.

Reason this repo exists

Often times web-applications need to benefit from connecting to scanners.

It's virtually impossible if we take a direct route to a scanner via DLL located on clients' computers, because web browsers don't have permission to utilize those resources.

Sometimes it is often suggested to use:

1. ActiveX: Allows you to communicate directly with DLLs. It propriety code, limited to IE, and has security problems.

2. Java applets: Communicate directly with DLLs. Except, the support of Java applets is dying. Chrome/FF don't support this anymore.

3. Silverlight / Flash... no.

Solution

Have a 'Web Agent' which acts as a local server that accepts HTTP requests.

Based on the HTTP requests, we call the appropiate DLL or execute commands.

A web agent is a link between the browser and the internals of the computer.

Further read: https://wicg.github.io/webusb/ - Chrome's WebUSB API. This also limited to Chrome.

Roadmap

• Allow user to select which scanner to choose from.
• A GUI for the web agent.
• Web agent can be minimized to tray.
• Allow web agent to be added to the system's startup & be minimized on boot.
• Work on API.

Code documentation style

This project will use Sphinx.

License

This package is open-sourced software licensed under the MIT license.

Credit

saochishti - https://github.com/soachishti/pyScanLib

chmuche - https://github.com/ndp-systemes/pyScanLib (multi-page scan code)