An image acquisition device compresses a media signal representative of a scene based on a sensing matrix that is a determined by a sensing matrix template and a set of template parameters. The image acquisition device provides the compressed media signal to a receiver and selectively provides a specification of a subset of the set of template parameters to the receiver. The receiver extracts one or more scene descriptors representative of one or more portions of the scene from the compressed media signal using the sensing matrix template without knowledge of the template parameters that are not included in the subset. The template parameters that are not included in the subset are not received by the receiver.