A sneak peek into the camcorder path
Cherif Ben Zid, Séverine Baudry, Bertrand Chupeau, Gwenaël Doërr · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2013
A number of technologies claim to be robust against content re-acquisition with a camera recorder e.g. water- marking and content ngerprinting. However, the benchmarking campaigns required to evaluate the impact of the camcorder path are tedious and such evaluation is routinely overlooked in practice. Due to the interaction between numerous devices, camcording displayed content modi es the video essence in various ways, including geometric distortions, temporal transforms, non-uniform and varying luminance transformations, saturation, color alteration, etc. It is necessary to clearly understand the di erent phenomena at stake in order to design ef- cient countermeasures or to build accurate simulators which mimic these e ects. As a rst step in this direction, we focus in this study solely on luminance transforms. In particular, we investigate three di erent alterations, namely: (i) the spatial non uniformity, (ii) the steady state luminance response, and (iii) the transient luminance response.