Immersive video allows viewers to freely switch the viewpoints. The intensity of realistic experience greatly relies on the quality of synthesized depth maps. However, there exist distorted regions due to inaccurate depth estimation or compression.

Object detection under low-light surveillance is a crucial problem that less efforts have been made on it. In this paper, we proposed a hybrid method that jointly use enhancement and object detection for the above challenge, namely Dedark+Detection. In this method, the low-light surveillance video is processed by the proposed de-dark method, and the video can thus be converted to appearance under normal lighting condition. This enhancement bring more benefits to the subsequent stage of object detection. After that, an object detection network is trained on the enhanced dataset for practical applications under low-light surveillance. Experiments are performed on 18 low-light surveillance video test sequences, and superior performance can be found when comparing to state-of-the-arts.

Focal stack is an intermediate data representation obtained by projecting 4D light field (LF) in z-dimension. This kind of representation is fundamental for future interactive and immersive visual applications. However, focal stack images are a series of samples focused at varying depths of static scenes, which yields considerable redundancy among them. In this paper, we propose a Gaussian guided inter prediction model to eliminate the visual redundancy. In our work, the effect of the varying focus distance on plenoptic imaging system is characterized by the point spread function (PSF), and we propose a simplified Gaussian-like PSF to fit this characteristic according to the features of focal stack images. After that, Gaussian guided motion estimation and motion compensation are both implemented in this model. Experimental results show that our model can achieve smaller residual distribution. There are 10.33% bit rate saving and 0.397 dB PSNR gain on average in three configurations compared with HEVC anchor. Particularly, it brings about up to 16.60% bit rate saving with 0.649 dB PSNR increment in Low Delay P configuration.

Asymmetric coding methodology for multi-view video plus depth is a promising technique for future three-dimensional and multi-view driven visual applications for its superior coding performance in bandwidth limited conditions. Since the depth video suffers from asymmetric distortions corresponding to viewpoint, it's a challenge in smooth and quality consistent content based interaction. To solve this challenge, we propose a residual learning framework to enhance the quality of compression distorted multi-view depth video. In this work, we exploit the correlation between viewpoints to restore the target viewpoint depth maps by using multi-modality priors, which are depth maps from adjacent viewpoints with better quality and color frames in the same viewpoint. A residual network is designed to fully exploit the contribution from these priors. Experimental results show the superiority of our framework in the quality improvement on both decoded depth video and synthesized virtual viewpoint images.

Light field is the most prospective technology for interactive and immersive visual applications. and light field image is an intermediate data format that demands a large amount of storage space and higher transmission bandwidth. Therefore, compression of light field images is highly desired for further applications. In this paper, we propose a co-saliency guided bit allocation scheme with constraints of consistency among sub-aperture images. Firstly, saliency is jointly detected on color and depth images of sub-aperture by improving our previous model. The obtained pixel-wise co-saliency map is converted into block-wise via K-means clustering. In this way, the saliency weight of each coding tree unit (CTU) can be calculated. Then, target bits of each CTU are initially determined by the weight of each block. The allocation is adjusted dynamically under the guidance of co-saliency map and the image texture complexity. The experimental results show that BD-PSNR of 0.384 dB can be achieved for the salient region at the cost of less than 0.107 dB decrease for the whole image compared to HTM anchor. Moreover, subjective quality of proposed scheme outperforms the anchor for the salient region, and there is no noticeable distortion for non-salient region.

In this paper, we propose a method of illumination attribute coding method for virtual reality broadcasting system. As for the virtual reality content, it is captured with local illumination variations. Our method is motivated by the Phong illumination model, and illumination attribute is extracted from images and then an illumination reference is synthesized with higher correlation to the current image.

The rapid spreading of RGB-D cameras has led to wide applications of 3D videos in both academia and industry, such as 3D entertainment and 3D visual understanding. Under these circumstances, extensive research efforts have been dedicated to RGB-D camera--oriented topics. In these topics, quality promotion of depth videos with the temporal characteristic is emerging and important. Due to the limited exposure time of RGB-D cameras, object movement can easily lead to motion blurs in intensive images, which can further result in obvious artifacts (holes or fake boundaries) in the corresponding depth frames. With regard to this problem, we propose a depth error elimination method based on time series analysis to remove the artifacts in depth images. In this method, we first locate the regions with erroneous depths in intensive images by using motion blur detection based on a time series analysis model. This is based on the fact that the depth image is calculated by intensive color images that are captured synchronously by RGB-D cameras. Then, the artifacts, such as holes or fake boundaries, are fixed by a depth error elimination method. To evaluate the performance of the proposed method, we conducted experiments on 250 images. Experimental results demonstrate that the proposed method can locate the error regions correctly and eliminate these artifacts effectively. The quality of depth video can be improved significantly by using the proposed method.