Recent development of autostereoscopic displays demands the synthesis of more virtual views in wider baseline, an inevitable trend for future 3DTV systems. However, current standard file formats, e.g. multi-view coding (MVC) and image plus depth, encounter challenging problems to meet the request. Therefore, we propose a new file format, called reduced depth stereo image (RDSI), which saves the color and depth images of the left view and the disoccluded regions in the right view. Based on RDSI, rendering virtual images from parallel viewpoints along the baseline can be simplified as view interpolation that is not only very efficient but also consistent in disocclusion regions. Through experiments on both simulated and real data, we demonstrate the superior performance with several quantitative assessments for the adopted file format and the rendering algorithm. The results suggest RDSI as a better choice to meet the demands for the online synthesis of many virtual views in wide baseline for advanced autostereoscopic displays.