Under-display camera (UDC) provides an elegant solution for full-screen smartphones. However, UDC captured images suffer from severe degradation since sensors lie under the display. Although this issue can be tackled by image restoration networks, these networks require large-scale image pairs for training. To this end, we propose a modular network dubbed MPGNet trained using the generative adversarial network (GAN) framework for simulating UDC imaging. Specifically, we note that the UDC imaging degradation process contains brightness attenuation, blurring, and noise corruption. Thus we model each degradation with a characteristic-related modular network, and all modular networks are cascaded to form the generator. Together with a pixel-wise discriminator and supervised loss, we can train the generator to simulate the UDC imaging degradation process. Furthermore, we present a Transformer-style network named DWFormer for UDC image restoration. For practical purposes, we use depth-wise convolution instead of the multi-head self-attention to aggregate local spatial information. Moreover, we propose a novel channel attention module to aggregate global information, which is critical for brightness recovery. We conduct evaluations on the UDC benchmark, and our method surpasses the previous state-of-the-art models by 1.23 dB on the P-OLED track and 0.71 dB on the T-OLED track, respectively. Code is available at Github.

The new trend of full-screen devices encourages us to position a camera behind a screen. Removing the bezel and centralizing the camera under the screen brings larger display-to-body ratio and enhances eye contact in video chat, but also causes image degradation. In this paper, we focus on a newly-defined Under-Display Camera (UDC), as a novel real-world single image restoration problem. First, we take a 4k Transparent OLED (T-OLED) and a phone Pentile OLED (P-OLED) and analyze their optical systems to understand the degradation. Second, we design a novel Monitor-Camera Imaging System (MCIS) for easier real pair data acquisition, and a model-based data synthesizing pipeline to generate UDC data only from display pattern and camera measurements. Finally, we resolve the complicated degradation using learningbased methods. Our model demonstrates a real-time high-quality restoration trained with either real or the synthetic data. The presented results and methods provide good practice to apply image restoration to realworld applications.

We report light collimation from a point source without the space normally needed for fan-out. Rays emerge uniformly from all parts of the surface of a blunt wedge light-guide when a point source of light is placed at the thin end and the source's position determines ray direction in the manner of a lens. A lenticular array between this light-guide and a liquid crystal panel guides light from color light-emitting diodes to designated sub-pixels thereby removing the need for color filters and halving power consumption but we foresee much greater power economies and wider application.

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We have demonstrated a backlight which emits collimated light whose direction can be scanned through 16°. Combined with a high frame rate LCD, this lets us display stereo 3D with no need for glasses.