With the development of cloud computing, high-capacity reversible data hiding in an encrypted image (RDHEI) has attracted increasing attention. The main idea of RDHEI is that an image owner encrypts a cover image, and then a data hider embeds secret information in the encrypted image. With the information hiding key, a receiver can extract the embedded data from the hidden image; with the encryption key, the receiver reconstructs the original image. In this paper, we can embed data in the form of random bits or scanned documents. The proposed method takes full advantage of the spatial correlation in the original images to vacate the room for embedding information before image encryption. By jointly using Sudoku and Arnold chaos encryption, the encrypted images retain the vacated room. Before the data hiding phase, the secret information is preprocessed by a halftone, quadtree, and S-BOX transformation. The experimental results prove that the proposed method not only realizes high-capacity reversible data hiding in encrypted images but also reconstructs the original image completely.

Surveillance systems focus on the image itself, mainly from the perspective of computer vision, which lacks integration with geographic information. It is difficult to obtain the location, size, and other spatial information of moving objects from surveillance systems, which lack any ability to couple with the geographical environment. To overcome such limitations, we propose a fusion framework of 3D geographic information and moving objects in surveillance video, which provides ideas for related research. We propose a general framework that can extract objects’ spatial–temporal information and visualize object trajectories in a 3D model. The framework does not rely on specific algorithms for determining the camera model, object extraction, or the mapping model. In our experiment, we used the Zhang Zhengyou calibration method and the EPNP method to determine the camera model, YOLOv5 and deep SORT to extract objects from a video, and an imaging ray intersection with the digital surface model to locate objects in the 3D geographical scene. The experimental results show that when the bounding box can thoroughly outline the entire object, the maximum error and root mean square error of the planar position are within 31 cm and 10 cm, respectively, and within 10 cm and 3 cm, respectively, in elevation. The errors of the average width and height of moving objects are within 5 cm and 2 cm, respectively, which is consistent with reality. To our knowledge, we first proposed the general fusion framework. This paper offers a solution to integrate 3D geographic information and surveillance video, which will not only provide a spatial perspective for intelligent video analysis, but also provide a new approach for the multi-dimensional expression of geographic information, object statistics, and object measurement.

The sensor drift problem is objective and inevitable, and drift compensation has essential research significance. For long-term drift, we propose a data preprocessing method, which is different from conventional research methods, and a machine learning framework that supports online self-training and data analysis without additional sensor production costs. The data preprocessing method proposed can effectively solve the problems of sign error, decimal point error, and outliers in data samples. The framework, which we call inertial machine learning, takes advantage of the recent inertia of high classification accuracy to extend the reliability of sensors. We establish a reasonable memory and forgetting mechanism for the framework, and the choice of base classifier is not limited. In this paper, we use a support vector machine as the base classifier and use the gas sensor array drift dataset in the UCI machine learning repository for experiments. By analyzing the experimental results, the classification accuracy is greatly improved, the effective time of the sensor array is extended by 4–10 months, and the time of single response and model adjustment is less than 300 ms, which is well in line with the actual application scenarios. The research ideas and results in this paper have a certain reference value for the research in related fields.