An efficient DIBR method based on depth offset mapping (DOM) by calculating the normalized offset between referenced image and shifted image using only an original picture and the corresponding grayscale depth map is proposed to realize 3D display. During the synthesizing progress, 3D image can be obtained directly by the mapping relations of related pixels according to the depth cue from corresponding depth map. Instead of generating virtual view-points in traditional DIBR method, the proposed method has a fast calculation speed and a high synthesizing efficiency which can complete the image rendering based on hardware devices with better iterative performance. In experiments, the speed of synthesizing 3D image is analyzed and a 10-second long video including 240 frames is used to verify the real-time implementation. Results show that the proposed method can realize a real-time rendering of 3D video with 3840×2160 resolution with about 10.68ms per frame for average on a smart Android motherboard (Rockchip RK3399). The proposed system is more portable and a high integration is realized by using RK3399 instead of the off-the-shelf computer hardware (2.2 GHz Eight-core CPU and a GTX-1080 GPU).