Evaluating the Effect of Watermarking on Analysis of Functional Magnetic Resonance Images

fMRI images are a collection of brain MRI-images acquired during a sensory-motor cognitive experiment, and are dedicatedto detect the activated regions of the brain. Information of the fMRI experiment, during which the data has been collected, is one of the rudimentary parts for analyzing the images, usually delivered to the neurologist besides the images. The new method, introduced in this paper, organizes mentioned information into a code frame, and embeds such frame inside the images as a watermark. The suggested method modifies the DCT coefficients of images, to provide a robust embedded code. This code avoids any significant damages in activation detection processes in case of probable failure in extraction. We applied the proposed method in order to embed parameters of experiment into fMRI images of a visual task. Then the effect of unextracted watermark is evaluated on two conventional activation detection procedures (t-test and cross-correlation), indicating trivial changes in the activation maps