High capacity data hiding with absolute moment block truncation coding image based on interpolation.

Data hiding is a way of hiding secret data on cover-media and it is used for a variety of applications. An important of the data hiding is to conceal the data in a secret way without loss of cover-media. Until now, continuous research on absolute moment block truncation coding based data hiding methods have improved a performance on data concealment and image quality. However, the current absolute moment block truncation coding based data hiding technology has a limitation in deriving a method that significantly surpasses existing performance. In this paper, we propose a new method to overcome this problem. To do this, first the original image is transformed to the cover image using absolute moment block truncation coding and is expanded the image using neighbor average interpolation algorithm. The proposed three data hiding methods are based on the generated cover image. The first method is to directly replace the pixel value, which is a component of each block, with the same secret value. The second method is to replace the pixels to match the secret bits only for the extended pixels in each block of the cover image. The third method is to apply Hamming code to each block to minimize the number of replacement pixels for data hiding. Experimental results show that our method is superior in terms of efficiency compared to traditional absolute moment block truncation coding based data hiding methods.

The effects of 3 weeks of rTMS treatment on P200 amplitude in patients with depression.

Previous studies have reported that repetitive transcranial magnetic stimulation (rTMS) induces neuronal plasticity in the brain. Although event-related potential (ERP) is an exploration tool, the rTMS effects on ERPs in patients with major depression have not been fully explored. We demonstrated that rTMS treatment induces changes in brain function in patients with medication-resistant major depression using the ERP. Eighteen patients with medication-resistant major depression (five males and 13 females) participated in this study. The patients received rTMS treatment for 3 weeks. All patients completed clinical scales, including the Hamilton Depression Rating Scale (HAM-D), Hamilton Anxiety Scale (HAM-A), Beck Depression Inventory (BDI), State-Trait Anxiety Inventory (SAI, TAI), Ruminative Response Scale, Emotion Regulation Questionnaire, and Cognitive Emotion Regulation Questionnaire (CERQ), as well as the ERP auditory oddball task, at their first visit (baseline) and at the 3-week visit (3-weeks). The HAM-D, HAM-A, BDI, SAI, and "blaming others" scale of the CERQ decreased significantly after rTMS treatment. In ERP auditory oddball task, when FP1, FP2, FZ, FCZ, CZ, and PZ channels were analyzed, P200 amplitudes showed a main effect for time of measurement and increased after 3 weeks of rTMS treatment. Standardized low-resolution brain electromagnetic tomography showed significant activation in the left middle frontal gyrus by 3 weeks of rTMS treatment. The results suggest that relatively longer rTMS treatment induces changes in brain function in patients with medication-resistant major depression, which can be identified using ERP.