VCode—Pervasive Data Transfer Using Video Barcode

Abstract

In this paper, we describe a novel data transfer scheme that uses the camera in a smart phone as an alternative data channel. The data is encoded as a sequence of 2-D barcode images, displayed on a flat panel display, acquired by the camera, and decoded in real time by the software embedded in device. The decoded data is written to a file. Compared with existing data channels, such as CDMA/GPRS, cables, Bluetooth, and Infrared, our method relies on visual communication and does not require special hardware or data plans. Users only need to point the camera at a monitor displaying the VCode to download. Technical challenges to overcome include correction of perspective distortion, compensation for contrast variation, and efficient implementation of small footprint software into a mobile device. We address these challenges and present our solution in detail. We have implemented a prototype which allows users to download various types of files successfully, including pictures, ring tones and Java games onto camera phones running Symbian and Windows Mobile platforms. We discuss the limitations of our solution and outline future work to overcome these limitations.

Barcode Modulation Method for Data Transmission in Mobile Devices

“…Normally the intensity levels on the LCD goes from 0 to . So values are transformed linearly to this range using the following equation: (4) Thus the average power of is maximized for LCD projection.…”

“…This idea has been implemented in [4] where transmission of data between two cell phones through a series of 2D QR codes is studied, achieving bit rates of under 10 kbps for state of the art mobile devices. Later the idea was further developed in [5] in which a computer monitor and a digital camera are used for transmission and reception with bit rates of more than 14 Mbps achieved in docked transmitter and receiver conditions over distances of up to 4 meters.…”

Dynamic QR Codes for Augmented Reality

“…Liu et al [14] projetaram um sistema para transferência de dados via códigos de barras, denominado VCode. Esse sistema codifica um arquivo qualquer em uma sequência de códigos de barras que são exibidos em algum display.…”