Human plays a key role in metaverse and digital twin systems and thus live three-dimensional (3D) human shape reconstruction brings significant improvement for highly accurate anthropomorphic measurements. However, it is still difficult to obtain detailed 3D computational models or “virtual humans” due to the diversity of individual poses and shape deformation. With technical advantages of the metaverse geometric modeling, virtual characters can be created in seconds. Concurrent, tremendous progress has been achieved in 3D modeling technology and larger representative public human datasets have emerged. In this survey, the status quo of 3D body digitization is investigated, and the accompanying processing pipeline is introduced. Specifically, this survey first discusses mainstream 3D scanning technologies for virtual 3D body acquisition. Second, we investigate the status quo of the commonly-used body measurement processing frameworks from four aspects: 1) data acquisition; 2) feature extraction; 3) surface modeling; and 4) landmarking and digital measurements. Finally, through a comparative analysis of prior works, we highlight challenges and new trends of ongoing developments based on insights into the advantages and limitations of existing works.

In this letter, we present a hyperspectral image (HSI) mixed-noise removal method named Moreau-enhanced total variation (TV) regularized local low-rank matrix recovery (LLRMTV). The rank-fixed matrix recovery is first adopted to separate the low-rank clean HSI patches from the sparse noise. Then, a Moreau-enhanced TV regularized image reconstruction strategy is utilized to ensure the piecewise smoothness of the reconstructed image from the low-rank patches. The proposed Moreau-enhanced TV restoration method involves a nonconvex penalty designed to maintain the convexity of the objective function. Moreover, the proposed model is integrated into an augmented Lagrange multiplier (ALM) algorithm to produce final results, leading to a complete HSI restoration framework. Examples of restoration illustrate the improvement over the typical TV regularization.

Effective infrared small target detection is still challenging due to small target sizes and the clutter in the background. Unfortunately, many advanced methods do not perform well in preserving and detecting multi-scale objects in complex scenes. We propose an infrared small targets method to suppress the background and adapt the infrared small targets with different sizes. Based on the singular value analysis in the facet model, we propose a multi-derivative descriptor to enhance the targets and suppress various clutter in the dual derivative channels. In the first-order derivative channel, we design four facet kernels with different directions to enhance and preserve the isotropic small targets and suppress the block clutter. In the second-order derivative channel, we use the facet kernel to enhance the center pixels of targets and suppress the band clutter. In order to adapt to the targets with various sizes, we propose a constrained random walker technique, including an adaptive matching algorithm to extract the local regions of each candidate adaptively based on the constraint of size and shape. The experimental results demonstrate that the proposed method can accurately detect multi-scale small targets in complex scenes, resulting in better detection performance than the state-of-the-art methods.

The fusion of hyperspectral and multispectral images involves integrating high spectral resolution hyperspectral image (HSI) and high spatial resolution multispectral image (MSI) to generate a HSI with high spatial and spectral resolution (HR-HSI). Existing HSI-MSI fusion methods primarily focus on information fusion within the spatial domain; however, few solutions have explored the employment of frequency analysis to enhance spatial resolution, limiting their capability for global perception. In this paper, we propose an efficient and novel paradigm for HSI-MSI fusion through the cross-frequency enhanced spatial-spectral fusion network, named CESFusion, exploring the complementary fusion of information between the spatial and frequency domains. Specifically, we first present the cross-frequency domain fusion module (CFFM) to perform global analysis through the Fourier transform and effectively integrate and enhance the frequency domain information from both HSI and MSI. Subsequently, we propose the spectral modeling module (SpeMM) based on state space model (SMM) to capture long-range spectral dependencies with linear complexity, and integrate it with the spatial residual block-based module (SRM) for joint spatial-spectral feature extraction. Finally, to enable sufficient interaction between the spatial and frequency domains, we adopt the cross-domain interaction module (CDIM), capturing and integrating complementary information from both domains. Moreover, a frequency-based loss function is purposely designed to further improve the restoration of global information. Extensive experiments conducted on both synthetic and real datasets demonstrate the superiority of our CESFusion, as evidenced by both quantitative and qualitative evaluation results.

In this letter, we present a subspace-based nonlocal low-rank tensor approximation framework (SNLRTA) for hyperspectral image (HSI) restoration. The proposed method consists of a subspace learning method to achieve an accurate subspace characterization of HSI and a nonlocal low-rank tensor approximation to take spatial nonlocal self-similarity into consideration. Specifically, the HSI first exploits residual statistics on median filtered image to estimate a robust subspace. Laplacian scale mixture (LSM) modeling is then investigated to model tensor coefficients from overlapping cubes in low-rank subspace. Both the hidden scale parameters and the sparse coefficients therein are adaptively shrink, characterizing the sparsity of similar patches. Meanwhile, the $\ell _{1}$ data fidelity facilitates the implicit detection of outliers after median filtering. Substantiated by extensive experimental results, the proposed method outperforms several state-of-the-art approaches on mixed noise removal, qualitatively and quantitatively.