Camera view usage of binary infrared sensors for activity recognition

A ceiling sensor system is reported in this study to recognize different activities of multiple persons in the home environment. The sensors output binary sequences by which we know the existence/nonexistence of persons under the sensors. A short-period average of the binary response is shown to be regarded as a pixel value of a top view camera, but the camera-like view is more advantage in the sense of preserving privacy. Using the ”pixel values” as features, support vector machine (SVM) classifier succeeded to recognize eight activities of five subjects at average recognition rate of 80.10%. This accuracy is not sufficient in general but surprisingly high with such low-level information.