Effect of cover quantization on steganographic fisher information

摘要

This article presents an extension of the square root law of imperfect steganography to consider the effects of quantization on the steganographic Fisher information. We make the assumption that the cover elements are quantized i.i.d. samples drawn from an underlying continuous-valued ‘precover’ distribution. In the fine quantization limit, the Fisher information exhibits power scaling with an exponent determined jointly by the smoothness of the precover distribution and the properties of the embedding function. This extension is relevant for understanding the effects of pixel color depth and JPEG quality factor on secure payload of imperfect steganography realized using a mutually independent embedding operation.