The eLog library was initially developed as a research prototype and later published for lifelogging researchers in 2010 to help them easily analyze heterogenous data and complex visualization. It has been kept growing with the progress of mobile computing environments and recently its UI part is released with GPL v3 license for wider usage. The eLog UI library is optimized for mobile environment and can get easily integrated with existing Web services.

Who We Are

The original work was proposed by Pil Ho and later extended the work with collaboration with 28 researchers around the world who contributed their lifelogs, collaborated for lifelog analysis and share research results to build up an open lifelogging platform for the public. Pil Ho has been keeping the development updating the library following up the progress in mobile computing.


  • Nov. 2014: Change the web page skin using bootstrap.
  • Nov. 2014: Published elog UI library as GPL v3.
  • Oct. 2014: Version up eLog library and documentation.


Data collection and status

This page records the current status of e-log archives with technical analysis.

Data collection


ViconRevue is the wearable digital camera designed to take photos passively without intervention whilst being worn by the user. Based on Microsoft SenseCam technology, Revue is a research tool aimed at researchers as an aid for people with memory loss.


Vicon Revue contains a 1230mAh lithium-ion battery that lasts enough for one-day continuous shot. It is built around a PIC microcontroller. It has:

  • 1GB of flash memory
  • 4KB RAM
  • Many general purpose I/O (GPIO) lines
  • On-chip peripherals. 

Vicon Revue stores VGA resolution (640x480) images as compressed .JPG files on the 1GB flash memory card. The typical image size (around 30KB) allows over 30,000 photos to be stored in the camera.

ViconRevue has the wide-angle lens with indicator lights and buttons for manual shot and privacy pause. It embeds multiple sensors that tell much details on the environment surrounding the user:

  • ACC = 3 axis accelerometer data, the accelerometer triggers the camera but doesn’t get used by the software at this time.
  • TMP = Temperature in degrees C.
  • CLR = Light level, big number (3,000+) = lots of light.
  • BAT = Battery level in millivolts, max is around 41000.
  • MAG = Magnetometer readings in 3 axis. This can be turned into a 'compass' reading but I don’t have any details on this at the moment.
  • PIR = Passive infrared sensor. 0 or 1 where 1 means that there is some moving IR source (typically a person) in view.

Three letter acronyms above are the ID of the sensing records stored in the ViconRevue memory. Records consist of image files and SENSOR.CSV text file. SENSOR.CSV include the timestamped sensing data of image and above sensors.

To get some sample videos composed of pictures captured with Revue, visit ViconRevue YouTube channel.

iPhone 3GS

I use iPhone to capture the location information using MotionX GPS app. See the example below.


Programmed using PHP for GMail IMAP acccess to monitor all email activities.

Phone records

Collecting from the phone bill.

People identification

Currently using PICASA to identify people face and classification from ViconRevue images. I am considering using Face.com open API for automated face recognition.


As of October 29th, 2010 since July 9th, 2010.  

  • ViconRevue Sensing records:1,820,779
  • Images: 327,542
  • GPS points: 32,473
  • Human faces: 7,658
  • Idenfitied people: 126
  • E-mails: 8,337
  • Phone records: 243