%0 Journal Article %T Contextual Information and Covariance Descriptors for People Surveillance: An Application for Safety of Construction Workers %A Giovanni Gualdi %A Andrea Prati %A Rita Cucchiara %J EURASIP Journal on Image and Video Processing %D 2011 %I Springer %R 10.1155/2011/684819 %U http://dx.doi.org/10.1155/2011/684819