Single-pixel imaging is an alternate imaging technique particularly well-suited to imaging modalities such as hyper-spectral imaging, depth mapping, 3D profiling. However, the single-pixel technique requires sequential measurements resulting in a trade-off between spatial resolution and acquisition time, limiting real-time video applications to relatively low resolutions. Compressed sensing techniques can be used to improve this trade-off. However, in this low resolution regime, conventional compressed sensing techniques have limited impact due to lack of sparsity in the datasets. Here we present an alternative compressed sensing method in which we optimize the measurement order of the Hadamard basis, such that at discretized increments we obtain complete sampling for different spatial resolutions. In addition, this method uses deterministic acquisition, rather than the randomized sampling used in conventional compressed sensing. This so-called ‘Russian Dolls’ ordering also benefits from minimal computational overhead for image reconstruction. We find that this compressive approach performs as well as other compressive sensing techniques with greatly simplified post processing, resulting in significantly faster image reconstruction. Therefore, the proposed method may be useful for single-pixel imaging in the low resolution, high-frame rate regime, or video-rate acquisition.

We propose a self-adaption focal length adjustment method of a compound and human hybrid eye with a non-uniform microlens array model (NUMLA) to reduce defocus aberration by using the liquid lens. The models are deduced and verified through simulations. The method can self-adaptively adjust the focal length according to object distance and image distance. The results show that (1) the RMS spot radii of the traditional uniform microlens array at different rings are 21 μm, 187 μm, 304 μm, 526 μm, and 803 μm. However, those of the NUMLA are 21 μm, 47 μm, 98 μm, 178 μm, and 287 μm, which indicates that the NUMLA can reduce the defocus aberration. (2) When the object distance and the image distance vary, the defocus aberration can be significantly reduced through the adjustment of the focal length, which validates the effectiveness of the proposed method. (3) The volumes of the liquid lens in the cavity at the peripheral rings are larger than that at the central rings. The results are beneficial for providing a simple solution to reduce the defocus aberration of the compound and human hybrid eye.

A compound eye and retina-like combination sensor based on a space-variant curved micro lens array (CMLA) is proposed to simultaneously offer the large FOV characteristic of a compound eye and retina-like feature of a single aperture eye. The mathematical models of the sensor are developed and the structure parameters of the space-variant CMLA are deduced. Modeling verification is carried out and the results show that the whole field of view (FOV) of the sensor is 105° and the optical information loss rate is 0.06 when the sector is 32. Imaging simulations illustrate that the sensor possesses the retina-like property, i.e., logarithmic-polar transformation. Meanwhile, the simulation results indicate that the overlapping angles between the two micro lenses on the adjacent rings can be reduced by decreasing the rings and the blind radius, and increasing the sectors. This work is beneficial for large FOV and time-efficient applications.

Single-pixel imaging techniques extend the time dimension to reconstruct a target scene in the spatial domain based on single-pixel detectors. Structured light illumination modulates the target scene by utilizing multi-pattern projection, and the reflected or transmitted light is measured by a single-pixel detector as total intensity. To reduce the imaging time and capture high-quality images with a single-pixel imaging technique, orthogonal patterns have been used instead of random patterns in recent years. The most representative among them are Hadamard patterns and Fourier sinusoidal patterns. Here, we present an alternative Fourier single-pixel imaging technique that can reconstruct high-quality images with an intensity correlation algorithm using acquired Fourier positive–negative images. We use the Fourier matrix to generate sinusoidal and phase-shifting sinusoid-modulated structural illumination patterns, which correspond to Fourier negative imaging and positive imaging, respectively. The proposed technique can obtain two centrosymmetric images in the intermediate imaging course. A high-quality image is reconstructed by applying intensity correlation to the negative and positive images for phase compensation. We performed simulations and experiments, which obtained high-quality images, demonstrating the feasibility of the methods. The proposed technique has the potential to image under sub-sampling conditions.

To mitigate the conflict between imaging quality and speed, a spatially adaptive retina-like sampling method for 3-D imaging Lidar based on time-of-flight method is proposed. The differences between previous retina-like sampling method and the proposed method are described. Sampling points with dense distribution is for the area of interest while sparse distribution is for the area of uninterest, which obtains high imaging quality while consuming much less data acquisition time. Mathematical models of the spatially adaptive retina-like method are developed, and the key parameters are analyzed. To validate the spatially adaptive retina-like sampling method, we perform situational simulations to compare the proposed method with the previous one. Results demonstrate that the proposed method is capable of decreasing data acquisition time without considerable distortion of the interested target. Furthermore, the proposed method is analyzed under different scenes for single and multiple targets. Results illustrate that the proposed method performs better than the previous method.

Based on the project experience in some shipyard, it is a trivial issue to manage assembly blocks at a shipyard. In order to improve the current status of shipbuilding stockyard scheduling, this study points out difficulties on the block stockyard operations, formalize the assembly block storage location problem with time window constrains on block inbound and block move movement-cost as the objective to be minimized, and five strategies for moving the obstructive blocks are proposed, and genetic algorithm is developed to transport the assembly blocks, the purpose of which is to reduce the number of obstructive blocks and reduce fuel consumption of transporters. At last using the real production data of a shipbuilding factory to analysis the performance of the algorithm and the strategy.

Anomaly detection is hampered by band redundancy and the restricted reconstruction ability of spectral–spatial information in hyperspectral remote sensing. A novel hyperspectral anomaly detection method integrating differential attribute profiles and genetic algorithms (DAPGA) is proposed to sufficiently extract the spectral–spatial features and automatically optimize the selection of the optimal features. First, a band selection method with cross-subspace combination is employed to decrease the spectral dimension and choose representative bands with rich information and weak correlation. Then, the differentials of attribute profiles are calculated by four attribute types and various filter parameters for multi-scale and multi-type spectral–spatial feature decomposition. Finally, the ideal discriminative characteristics are reserved and incorporated with genetic algorithms to cluster each differential attribute profile by dissimilarity assessment. Experiments run on a variety of genuine hyperspectral datasets including airport, beach, urban, and park scenes show that the effectiveness of the proposed algorithm has great improvement with existing state-of-the-art algorithms.

In this paper, focusing on the needs of near-field measurement lighting, a lighting system with high collimation and uniformity is designed, using filament high-heat illuminant as radiation source. The general design idea of dividing the illumination system into “collimating optical cavity” and “homogenizing optical cavity” is put forward. The design process of “collimating optical cavity” is given, and two different structural forms of “homogenizing optical cavity” are analyzed and the design results are given. The lighting effect is obtained by using simulation software, and the established parameters are achieved.