Activity Recognition using Visual Tracking and RFID

Summary:

In this paper, authors have presented the use of computer vision and RFID information for capturing the activity of the subject. Using the standard methods based on skin color based segmentation, they obtain the skinny region (hands face). By using the information about the area of the bounding box, they recognize the hands and track them.

All the objects are having a RFID tag which is read through a RFID reader. The RFID reader consists of an antenna which emits the enery that is used by the RFID tag to get charged. The RFID antenna is periodically switched off during which, the capacitor in the RFID tag looses charge which communicates the ID of the Tag back to the reader by modulation of the energy. The authors have modified the above mentioned mechanism is modified in which the reader is provided with the aditional capability of capturing the voltage values emitted by the RFID tags.

Since the tag would receive maximum signal when it is normal to the antenna field. The variation in the energy received and emitted can be used to capture the orientation information about the ibject being manipulated by the user.

In a nut shell:

RFID tag is used to capture if the object is being manipulated by the user or not and what is the object being manipulated.

Computer Vision is used to obtain the position of the hand. If they are close to the object being manipulated (measured through RFID), it is said that user is approaching the object.


Tracking his hands along with the orientation information from the RFID tags is used to recognize activity. As an example they have shown the activity of a subject in a retail store environment.


Discussion:

This is really a nice and novice method of recognizing activity and may be it can be helpful in Dr Hammond's favorite "wokshop saw" activity also . But my concerns are:

1. If RFID can provide a good estimate of the distance.
2. If they are unaffected by presence of other magnetic devices in the proximity.


Over all it is a nice approach and as discussed in the class is a nice and cheap direction to look at for future research.