Beck-View Digitalize

Digitise Super 8 films with Python, OpenCV, ReactiveX, and the Adafruit FT232H Breakout Board.

Project Summary

This application is designed to digitalize Super 8 films. A modified Super 8 projector is equipped with a USB camera mounted in front of its lens. When a frame is positioned and at rest, an opto-coupler sends a signal to an Adafruit FT232H Microcontroller, which triggers the USB camera to capture the frame. The captured image is then processed using OpenCV.

The captured images can be reassembled into a movie with Beck-View-Movie.

Image: By Joergsam - Own work, CC BY-SA 3.0, Wikimedia Commons

ToDo

• Add pictures and description of modified projector

The circuit diagram:

The FT232H board connects via USB-C to a computer. It transmits opto-coupler signals to the computer, where OpenCV controls the USB camera and processes images.

• OK1 (GPIO C2): Synchronizes image capture
• OK2 (GPIO C3): Signals end of film
• LED (GPIO C1): Lights up while processing an image

With some adaptions this application can also be used for other purposes, such as taking pictures with a USB camera when a button is pressed, or at specified intervals (timelapse), or when triggered by a sensor.

You can reassemble the captured images into a movie with Beck-View-Movie.

Project Installation

Prerequisites

Ensure the FT232H Breakout Board is connected via USB to your computer.

Tools

Python 3 and pip must be installed. Upgrade pip to the latest version:

pip3 install --upgrade pip

Installation Steps

1. Clone the Repository:

   git clone https://github.com/JuPfu/beck-view-digitalize.git
   cd beck-view-digitalize

2. Install Dependencies:

pip install -r requirements.txt

Additional Manual Installation Steps

1. Set the environment variable BLINKA=1 for your operating system (refer to the Blinka installation instructions).
2. Driver installation
   • For Windows, install the FT232H driver by means of Zadig.
   • For macOS, install the libusb library via brew.

The next chapters give some background about the libraries used and some detailed installation instructions in case of problems.

Detailed Installation Instructions

BLINKA

Blinka is a pip-installable Python library that runs on desktop Python. It supports USB adapter boards like the FT232H Adafruit breakout board, allowing hardware operations like GPIO, I2C, and SPI through USB connections.

Ensure the environment variable BLINKA is set correctly. Follow the platform-specific Blinka installation instructions.

PyFtdi for FT232H

PyFtdi aims at providing a user-space driver for popular FTDI devices, implemented in pure Python language. Supported FTDI devices include the FT232H Adafruit Breakout board.

In case of problems install PyFTDI for your platform using the PyFtdi Documentation.

Fix Driver with Zadig (Windows)

To fix the FT232H driver on Windows, use Zadig.

For troubleshooting, refer to the Arduino Help Center.

libusb for macOS

Install libusb using Homebrew:

brew install libusb

Verify the installation with:

brew ls libusb

Expected output:

/usr/local/Cellar/libusb/1.0.26/include/libusb-1.0/libusb.h
/usr/local/Cellar/libusb/1.0.26/lib/libusb-1.0.0.dylib
/usr/local/Cellar/libusb/1.0.26/lib/pkgconfig/libusb-1.0.pc
/usr/local/Cellar/libusb/1.0.26/lib/ (2 other files)
/usr/local/Cellar/libusb/1.0.26/share/libusb/ (9 files)

Validation

Taking a Photograph with a Press of a Button

An easy way to test the application without a modified Super V8 projector at hand is to use the simple circuit shown in the following images. Attach the FT232H Breakout board to a USB port of your computer. When starting the program supply the device number of your camera via the -d option. At the moment you have to guess the device id. Start with 0 (default if no device id is specified) and increment the device id by 1 until the preferred USB camera is activated. Eligible cameras are the builtin camera of your notebook, a connected USB-camera or on macOS an IPhone can also be selected, if in the same Wi-Fi.

Ensure everything is set up correctly by taking an image. Each pressing of the left button simulates a signal of an opto-coupler. The Ft232hConnector class receives the signal and sends it to your computer. The DigitizeVideo class handles the streams of signals. On each signal from the FT232H microcontroller the configured USB-camera is requested to take a picture. A press on the right button (end of film) terminates the program.

Contributing

1. Fork the Repository
2. Create a Feature Branch:

   git checkout -b feature/your-feature

3. Commit Changes:

   git commit -m 'Add some feature'

4. Push to the Branch:

   git push origin feature/your-feature

5. Open a Pull Request

License

This project is licensed under the MIT License. See the LICENSE file for details.

Acknowledgements

• Thanks to the contributors of OpenCV, ReactiveX, and Adafruit for their libraries and support.

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Follow these instructions to set up and use the Beck-View Digitalize application for digitizing Super 8 films or other image capture projects. Happy digitizing!