choice of technology

In the design process one of the main choice was which technology rely on to retrieve information from the Internet and to visualize it. In a project heavily based on technology the tool is plays a major part in user experience.
The project needed a tool that can be used in a supermarkets, can recognize products, access the Internet and display information in a visual form.

Microsoft media cart was discarder because it is bound to supermarkets ownership, this makes independent information hard to access. A supermarket owned "smart trolley" rises also privacy issues, FoodTracer project is heavily based on the collection of shopping information, the protection of personal data was one of the main issues during the design process.

A personal device such as mobile phone appeared as the best choice to preserve privacy. Other benefits of using a mobile phone are the wide diffusion and people confidence in using them. It also gives a perceived simplicity deriving from the familiarity with the device.

For what concern product recognition, supermarkets relies on optical barcodes. Barcodes require special scanners to be read and they are often hidden on the packaging. They do not provide the immediacy of interaction needed by the project.
RFID was discarded because its invisibility makes difficult to determine from which product the information comes from in a context where hundreds of products seek for attention.

Standard barcodes on the back label of wine bottles.

Finally d-touch was chosen, d-touch is a visual marker recognition system.
D-touch markers can be read in real time by a mobile phone and they can be designed with a certain degree of freedom, that gave the possibility to nicely integrate them on the front label of food packaging. Having a marker "hidden" in the front label gives users the perception of interacting with the product instead of the need to look for an intrusive barcode, often situated on the back label.
Moreover, the use of a camera makes interaction easier than barcode scanners or RFID readers because it can be compared to the already known action of taking a picture with a digital camera.

Example of d-touch visual marker used in the project