Digital image indexing using secret sharing schemes: a unified framework for single-sensor consumer electronics

This paper introduces a color filter array (CFA) image indexing approach for cost-effective consumer electronics with image capturing capability. Using a secret sharing technique, the proposed method indexes captured images directly in the single sensor digital camera, mobile phone and pocket device by embedding metadata information in the CFA domain. The metadata are used to determine ownership, capturing device identification numbers, and to provide time and location information. Additional semantic information could be added in the metadata by the end-user through the mobile phone´s or pocket device´s keyboard. After the metadata are embedded to the CFA image, the subsequent demosaicking step reconstructs a full color RGB image with excellent visual quality. The metadata information can be extracted from the CFA images. Alternatively, it can be recovered by the demosaicked images in personal image databases using PC software commonly available by camera manufacturers or with conventional public image database tools. The uniqueness and efficiency of the proposed approach are demonstrated here by employing a common Bayer CFA based imaging pipeline, however, the approach is suitable for other, non-Bayer CFA patterns, as well.