Digital Video Acquisition Research Articles

Digital Video Acquisition and Optimization Techniques for Effective Animal Tracking in Behavioral Ecotoxicology.

Behavioral phenotypic analysis is an emerging and increasingly important toolbox in aquatic ecotoxicology. In this regard digital video recording has recently become a standard in obtaining behavioral data. Subsequent analysis requires applications of specialized software for detecting and reconstructing animal locomotory trajectories as well as extracting quantitative biometric endpoints associated with specific behavioral traits. Despite some profound advantages for behavioral ecotoxicology, there is a notable lack of standardization of procedures and guidelines that would aid in consistently acquiring high-quality digital videos. The latter are fundamental for using animal tracking software successfully and to avoid issues such as identification switching, incorrect interpolation, and low tracking visibility. Achieving an optimized tracking not only saves user time and effort to analyze the results but also provides high-fidelity data with minimal artifacts. In the present study we, for the first time, provide an easily accessible guide on how to set up and optimize digital video acquisition while minimizing pitfalls in obtaining the highest-quality data for subsequent animal tracking. We also discuss straightforward digital video postprocessing techniques that can be employed to further enhance tracking consistency or improve the videos that were acquired in otherwise suboptimal settings. The present study provides an essential guidebook for any aquatic ecotoxicology studies that utilize digital video acquisition systems for evaluation of behavioral endpoints. Environ Toxicol Chem 2022;41:2342-2352. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Deep Recurrent Neural Network with Multi-Scale Bi-directional Propagation for Video Deblurring

The success of the state-of-the-art video deblurring methods stems mainly from implicit or explicit estimation of alignment among the adjacent frames for latent video restoration. However, due to the influence of the blur effect, estimating the alignment information from the blurry adjacent frames is not a trivial task. Inaccurate estimations will interfere the following frame restoration. Instead of estimating alignment information, we propose a simple and effective deep Recurrent Neural Network with Multi-scale Bi-directional Propagation (RNN-MBP) to effectively propagate and gather the information from unaligned neighboring frames for better video deblurring. Specifically, we build a Multi-scale Bi-directional Propagation (MBP) module with two U-Net RNN cells which can directly exploit the inter-frame information from unaligned neighboring hidden states by integrating them in different scales. Moreover, to better evaluate the proposed algorithm and existing state-of-the-art methods on real-world blurry scenes, we also create a Real-World Blurry Video Dataset (RBVD) by a well-designed Digital Video Acquisition System (DVAS) and use it as the training and evaluation dataset. Extensive experimental results demonstrate that the proposed RBVD dataset effectively improve the performance of existing algorithms on real-world blurry videos, and the proposed algorithm performs favorably against the state-of-the-art methods on three typical benchmarks. The code is available at https://github.com/XJTU-CVLAB-LOWLEVEL/RNN-MBP.

Extended 3D-PTV for direct measurements of Lagrangian statistics of canopy turbulence in a wind tunnel

Direct estimation of Lagrangian turbulence statistics is essential for the proper modeling of dispersion and transport in highly obstructed canopy flows. However, Lagrangian flow measurements demand very high rates of data acquisition, resulting in bottlenecks that prevented the estimation of Lagrangian statistics in canopy flows hitherto. We report on a new extension to the 3D Particle Tracking Velocimetry (3D-PTV) method, featuring real-time particle segmentation that outputs centroids and sizes of tracer particles and performed on dedicated hardware during high-speed digital video acquisition from multiple cameras. The proposed extension results in four orders of magnitude reduction in data transfer rate that enables to perform substantially longer experimental runs, facilitating measurements of convergent statistics. The extended method is demonstrated through an experimental wind tunnel investigation of the Lagrangian statistics in a heterogeneous canopy flow. We observe that acceleration statistics are affected by the mean shear at the top of the canopy layer and that Lagrangian particle dispersion at small scales is dominated by turbulence in the wake of the roughness elements. This approach enables to overcome major shortcomings from Eulerian-based measurements which rely on assumptions such as the Taylor’s frozen turbulence hypothesis, which is known to fail in highly turbulent flows.

Research on Video Remote Transmission Technology Based on FPGA

In order to solve the problem of remote transmission technology of high speed digital video in the application process, this paper takes FPGA technology as the core, uses the optical fiber communication, Camera link interface technology, and high-speed serial parallel conversion and so on to provide a technical proposal of a high-speed digital video remote transmission. First of all, this paper overall designs the remote transmission technology of digital video, and then designs its hardware circuit and system control logic, focuses on the specific design of digital video acquisition, high-speed data caching and decoding, data sending and receiving and analog camera data. Finally, the debugging and testing of the experimental transmission technology of the remote digital video are carried out, mainly for the single board debugging, analog transmission experiment, and video transmission experiment, in which the debugging results show that the FPGA minimum system meets the requirements. Transmitting and receiving communication circuit and serial communication circuit of Camera link are correct; high-speed serial parallel conversion chip and SFP peripheral circuit are stable and reliable; simulation experiments show that in the process of image transmission, the pixel clock, line effective, field effective; and the sequence of image data is controlled reasonably, which can well achieve image transmission. The video transmission experiment results show that the transmission technology designed can achieve the remote transmission of digital video.

Defeating Camcorder Piracy by Temporal Psychovisual Modulation

We present a new video projection technique to defeat camcorder piracy in movie theaters using the newly emerged display paradigm of temporal psychovisual modulation. The technique exploits the difference in image formation mechanisms between human eyes and digital cameras: in the human visual system, images are formed via continuous integration of the light field, whereas digital video acquisition is based on discrete sampling of light sensors. A movie frame is decomposed into multiple so-called shale frames such that, when these shale frames are displayed at a frame rate higher than 60 Hz, the human viewers will experience normal movie presentation without any noticeable artifacts, but the video frames captured by camcorders will contain severe, highly objectionable artifacts, depriving the pirated video contents of any commercial values.

A real-time system for acquisition and display of B-scan ophthalmic ultrasound images

Purpose: To present a new real-time system for acquisition and display of B-scan ophthalmic ultrasound images.Method: Firstly, the super video graphics array (SVGA) digital signal was acquired from the front-end of video graphics array (VGA) connector and then was transmitted to static random access memory and universal serial bus (USB) chip controlled by field-programmable gate array (FPGA). Secondly, the image-data (from SVGA signal) were encoded to reduce errors during transmission. Finally, the image-data were decoded by personal computer (PC) software to display and process.Result: This system made the B-scan ultrasound images transmit in real-time with a speed of 71 Mb s−1 and made the images display clearly.Conclusion: This study explored the feasibility of real-time transmission and display of B-scan ultrasound images with USB. Furthermore, it is indicated that digital video acquisition can transmit images with high fidelity and high speed, and can make the images easy to store and process.

A MAP Estimator for Simultaneous Superresolution and Detector Nonunifomity Correction

During digital video acquisition, imagery may be degraded by a number of phenomena including undersampling, blur, and noise. Many systems, particularly those containing infrared focal plane array (FPA) sensors, are also subject to detector nonuniformity. Nonuniformity, or fixed pattern noise, results from nonuniform responsivity of the photodetectors that make up the FPA. Here we propose a maximuma posteriori (MAP) estimation framework for simultaneously addressing undersampling, linear blur, additive noise, and bias nonuniformity. In particular, we jointly estimate a superresolution (SR) image and detector bias nonuniformity parameters from a sequence of observed frames. This algorithm can be applied to video in a variety of ways including using a moving temporal window of frames to process successive groups of frames. By combining SR and nonuniformity correction (NUC) in this fashion, we demonstrate that superior results are possible compared with the more conventional approach of performing scene-based NUC followed by independent SR. The proposed MAP algorithm can be applied with or without SR, depending on the application and computational resources available. Even without SR, we believe that the proposed algorithm represents a novel and promising scene-based NUC technique. We present a number of experimental results to demonstrate the efficacy of the proposed algorithm. These include simulated imagery for quantitative analysis and real infrared video for qualitative analysis.

Synchronous recording and review of oesophageal manometry and video fluoroscopy using a portable manometry recorder and PC with integrated digital video acquisition

We present the technical details of a new system for the synchronous recording and review of a combined oesophageal manometry and video fluoroscopic barium swallow examination. The system developed uses a portable manometry recorder and personal computer (PC) with an integrated digital video acquisition system. These are controlled using software to enable the real time capture of digital video and manometric data throughout the combined examination. The recorded pressure waveforms can then be synchronously displayed on a screen with the recorded digital video of the fluoroscopic barium swallow. This new tool enables both comparative measurement and detailed analysis of the relationship between visualized bolus transport and pressure measurements. It provides for a deeper understanding and improved clinical assessment of complex motility disorders over those obtained when these two modalities are applied separately. The system is easily incorporated into a clinical radiology suite and it is both user and patient friendly. It uses readily available computer hardware together with multimedia software and is a comparatively economical addition to the radiology suite with the manometry analysis available fulfilling the criteria laid down by the Clinical Associates Group of the British Society of Gastroenterology. Keywords: clinical environment, JPEG, oesophageal manometry, multimedia, real time system, synchronization