This paper presents an end-to-end neural mapping method for camera localization, encoding a whole scene into a grid of latent codes, with which a Transformer-based auto-decoder regresses 3D coordinates of query pixels. State-of-the-art camera localization methods require each scene to be stored as a 3D point cloud with per-point features, which takes several gigabytes of storage per scene. While compression is possible, the performance drops significantly at high compression rates. NeuMap achieves extremely high compression rates with minimal performance drop by using 1) learnable latent codes to store scene information and 2) a scene-agnostic Transformer-based auto-decoder to infer coordinates for a query pixel. The scene-agnostic network design also learns robust matching priors by training with large-scale data, and further allows us to just optimize the codes quickly for a new scene while fixing the network weights. Extensive evaluations with five benchmarks show that NeuMap outperforms all the other coordinate regression methods significantly and reaches similar performance as the feature matching methods while having a much smaller scene representation size. For example, NeuMap achieves 39.1% accuracy in Aachen night benchmark with only 6MB of data, while other compelling methods require 100MB or a few gigabytes and fail completely under high compression settings. The codes are available at https://github.com/Tangshitao/NeuMap.

We present a novel method for reconstructing clothed humans from a sparse set of, e.g., 1–6 RGB images. Despite impressive results from recent works employing deep implicit representation, we revisit the volumetric approach and demonstrate that better performance can be achieved with proper system design. The volumetric representation offers significant advantages in leveraging 3D spatial context through 3D convolutions, and the notorious quantization error is largely negligible with a reasonably large yet affordable volume resolution, e.g., 512. To handle memory and computation costs, we propose a sophisticated coarse-to-fine strategy with voxel culling and subspace sparse convolution. Our method starts with a discretized visual hull to compute a coarse shape and then focuses on a narrow band nearby the coarse shape for refinement. Once the shape is reconstructed, we adopt an image-based rendering approach, which computes the colors of surface points by blending input images with learned weights. Extensive experimental results show that our method significantly reduces the mean point-to-surface (P2S) precision of state-of-the-art methods by more than 50% to achieve approximately 2mm accuracy with a 512 volume resolution. Additionally, images rendered from our textured model achieve a higher peak signal-to-noise ratio (PSNR) compared to state-of-the-art methods.

This paper presents a neural network to estimate a detailed depth map of the foreground human in a single RGB image. The result captures geometry details such as cloth wrinkles, which are important in visualization applications. To achieve this goal, we separate the depth map into a smooth base shape and a residual detail shape and design a network with two branches to regress them respectively. We design a training strategy to ensure both base and detail shapes can be faithfully learned by the corresponding network branches. Furthermore, we introduce a novel network layer to fuse a rough depth map and surface normals to further improve the final result. Quantitative comparison with fused `ground truth' captured by real depth cameras and qualitative examples on unconstrained Internet images demonstrate the strength of the proposed method.

Abstract Since indoor scenes are frequently changed in daily life, such as re‐layout of furniture, the 3D reconstructions for them should be flexible and easy to update. We present an automatic 3D scene update algorithm to indoor scenes by capturing scene variation with RGBD cameras. We assume an initial scene has been reconstructed in advance in manual or other semi‐automatic way before the change, and automatically update the reconstruction according to the newly captured RGBD images of the real scene update. It starts with an automatic segmentation process without manual interaction, which benefits from accurate labeling training from the initial 3D scene. After the segmentation, objects captured by RGBD camera are extracted to form a local updated scene. We formulate an optimization problem to compare to the initial scene to locate moved objects. The moved objects are then integrated with static objects in the initial scene to generate a new 3D scene. We demonstrate the efficiency and robustness of our approach by updating the 3D scene of several real‐world scenes.

By utilizing the dataset provided by 3DLife/Huawei Challenge of ACM Multimedia, we propose a refreshing application that automatically evaluates player's energy consumption in gaming scenarios by a model with tracked skeleton, which may help users to know their exercise effects and even diet or reduce their weights. We develop a program to compute the energy consumption in real time by analyzing data captured from Microsoft Kinect, and also give a cue in the dynamic interaction. We model 3D human skeleton by joining different body parts with 15 nodes, and decompose player action into rigid body motions of these parts. Amount of energy consumed in the action is calculated as the sum of powers required to overcome gravity of each part. Experimental results show that instantaneous and total energy consumption of different dancers can be stably calculated. The hardware system is based on low-price Kinect, and easily accepted by users. The proposed application also provides a quantitative approach which help users to control their dining and exercise intensity.