Subtitle Region Selection of S3D Images in Consideration of Visual Discomfort and Viewing Habit

Abstract

Subtitles, serving as a linguistic approximation of the visual content, are an essential element in stereoscopic advertisement and the film industry. Due to the vergence accommodation conflict, the stereoscopic 3D (S3D) subtitle inevitably causes visual discomfort. To meet the viewing experience, the subtitle region should be carefully arranged. Unfortunately, very few works have been dedicated to this area. In this article, we propose a method for S3D subtitle region selection in consideration of visual discomfort and viewing habit. First, we divide the disparity map into multiple depth layers according to the disparity value. The preferential processed depth layer is determined by considering the disparity value of the foremost object. Second, the optimal region and coarse disparity value for S3D subtitle insertion are chosen by convolving the selective depth layer with the mean filter. Specifically, the viewing habit is considered during the region selection. Finally, after region selection, the disparity value of the subtitle is further modified by using the just noticeable depth difference (JNDD) model. Given that there is no public database reported for the evaluation of S3D subtitle insertion, we collect 120 S3D images as the test platform. Both objective and subjective experiments are conducted to evaluate the comfort degree of the inserted subtitle. Experimental results demonstrate that the proposed method can obtain promising performance in improving the viewing experience of the inserted subtitle.