Time-lapse of user captured video becomes popular in many applications recently, non-uniform sampling and digital video stabilization (VS) are usually two independent steps to keep meaningful contents and provide stabilized output. However, non-uniform sampling may produce large sampling interval and then result in larger motion, this would beyond the stabilization ability of VS and produce unpleasant output. To address this problem, we propose a new auto time-lapse framework, which selects frames not only based on camera motion scenarios, but also refer to the smoothed camera trajectory and considering VS ability according to Field of View (FOV) loss constraint. More specific, we introduce an advanced Markov chain (MC) model, in which smoothed camera trajectory, FOV loss constraint of VS, camera motion scenario, and sampling interval similarity between consecutive frames are encoded as potential functions. Finally, dynamic programming (DP) is employed to find the best non-uniform sampling. Experimental results demonstrate that the proposed method not only achieves pleasant and meaningful non-uniform sampling, but also provides satisfactory stabilization performance. The whole algorithm can work in real time during video recording on mobile device.

Though conventional implants have a capability of pressure regulation, they cannot maintain the intra-ocular pressure (IOP) desired for different patients. To solve these problems, an active glaucoma implant which consists of the valve actuator, pressure sensor, controller, and power supply, has been developed. In this paper, we first analyse of the operation of the conventional implant using a bond graph, and show its defects and limitations of the conventional valve analytically. Next, we design and analyze an electromagnetically driven valve actuator composed of a membrane, air-core solenoid, permanent magnet, and covering frame. To save the electrical power for operating the valve actuator, appropriate actuating methods are suggested and an optimal design of the valve actuator is carried out. Finally, using simulations, the possibility of the proposed valve actuator is investigated.