High Dynamic Range Image Watermarking

High Dynamic Range (HDR) images represent the future format for digital images since they allow more sensitive rendering. However, nowadays special types of preprocessing collectively known as tone mapping operators are needed to adapt HDR images to currently existing displays. Tone mapped images, although of reduced dynamic range, have nonetheless high quality and hence retain some commercial value. In this paper we propose a solution to the problem of HDR watermarking, e.g. for copyright embedding, that should survive tone mapping. Therefore, the requirements imposed on the watermark encompass imperceptibility, a certain degree of security and robustness to tone mapping operators. The proposed watermarking system belongs to the blind, detectable category, it is based on the QIM paradigm and employs a higher order statistic as feature. Preliminary experimental analysis shows positive results; more work is needed and currently underway.