Measurement of Small-Slope Free-Form Optical Surfaces with the Modified Phase Retrieval

In this paper, we demonstrate the use of the modified phase retrieval as a method for application in the measurement of small-slope free-form optical surfaces. This technique is a solution for the measurement of small-slope free-form optical surfaces, based on the modified phase retrieval algorithm, whose essence is that only two defocused images are needed to estimate the wave front with an accuracy similar to that of the traditional phase retrieval but with less image capturing and computation time. An experimental arrangement used to measure the small-slope free-form optical surfaces using the modified phase retrieval is described. The results of these experiments demonstrate that the modified phase retrieval method can achieve measurements comparable to those of the standard interferometer.

Dermoscopy as a diagnostic tool to differentiate between tinea pedis and plantar psoriasis

<p><strong>Background</strong>: Clinical differentiation between tinea pedis and plantar psoriasis may sometimes be challenging, with consequent diagnostic delays and unnecessary therapies; in such cases histopathological analysis helps to differentiate the 2 conditions. In this study we used a dermoscope as a non-invasive tool to investigate the significance of specific dermoscopic features and to improve their non-invasive differentiation.</p><p><strong>Methods:</strong> A clinical diagnosis of plantar psoriasis/tinea pedis was made on basis of accepted literature and proved by histopathology. Image capturing was performed using a dermoscope. Based on combination of history, clinical, and dermoscopic examination conclusive diagnosis with specific dermoscopic features for each disease was achieved.</p><p><strong>Results:</strong> The 15 patients of biopsy proven tinea pedis and 17 patients of biopsy proven plantar psoriasis were selected. We found that the presence of whitish powdery scales located in the furrows with apparently uninvolved skin in between was significant in tinea pedis whereas the presence of silvery white scales on a pinkish red erythematous background with regularly distributed red dots was significant in plantar psoriasis.</p><p><strong>Conclusions:</strong> Dermoscopy showed significant patterns in tinea pedis and plantar psoriasis due to their well-known different histological and physio pathological background, with white diffuse scales reflecting the dry and hyperkeratotic nature of plantar psoriasis and the red dots signifying the pin point blood vessels seen clinically as Auspitz sign. The peculiar scaling in tinea pedis might result from the predilection of dermatophytes to proliferate in moist environment, such as the furrows.</p>

Means and Methods of Efficiency Estimation of Video Stream Transmission Based on GigE Vision Technology Using Application Processor

The paper investigates the possibility of efficient implementation of a GigE Vision compatible video stream source on a computing platform based on a system-on-a-chip with general-purpose ARM processor cores. In particular, to implement the aforementioned video source, a proprietary prototype of a GigE Vision compatible camera was developed based on the Raspberry Pi 4 single-board computer. This computing platform was chosen due to its widespread use and wide community support. The software part of the camera is implemented using the Video4Linux and Aravis libraries. The first library is used for the primary image capturing from a video sensor connected to a single board computer. The second library is intended for forming and transmission of video stream frames compatible with GigE Vision technology over the network. To estimate the delays in the transmission of a video stream over an Ethernet channel, a methodology based on the Precise Time Protocol (PTP) has been proposed and applied. During the experiments, it was found that the software implementation of a GigE Vision compatible camera on single-board computers with general-purpose processor cores is quite promising. Without additional optimization, such an implementation can be successfully used to transmit small frames (with a resolution of up to 640 × 480 pixels), giving a delay less than 10 ms. At the same time, some additional optimizations may be required to transmit larger frames. Namely, a MTU (maximum transmission unit) size value plays the crucial role in latency formation. Thus, to implement a faster camera, it is necessary to select a platform that supports the largest possible MTU (unfortunately, it turned out that it is not possible with Raspberry Pi 4, as it supports relatively small MTU size of up to 2000 bytes). In addition, the image format conversion procedure can noticeably affect the delay. Therefore, it is highly desirable to avoid any frame processing on the transmitter side and, if it is possible, to broadcast raw images. If the conversion of the frame format is necessary, the platform should be chosen so that there are free computing cores on it, which will permit to distribute all necessary frame conversions between these cores using parallelization techniques.

A Domain Adaptive Person Re-Identification Based on Dual Attention Mechanism and Camstyle Transfer

Due to the variation in the image capturing process, the difference between source and target sets causes a challenge in unsupervised domain adaptation (UDA) on person re-identification (re-ID). Given a labeled source training set and an unlabeled target training set, this paper focuses on improving the generalization ability of the re-ID model on the target testing set. The proposed method enforces two properties at the same time: (1) camera invariance is achieved through the positive learning formed by unlabeled target images and their camera style transfer counterparts; and (2) the robustness of the backbone network feature extraction is improved, and the accuracy of feature extraction is enhanced by adding a position-channel dual attention mechanism. The proposed network model uses a classic dual-stream network. Comparative experimental results on three public benchmarks prove the superiority of the proposed method.

Bridging the Gap between Ophthalmology and Emergency Medicine in Community-Based Emergency Departments (EDs): A Neuro-Ophthalmology Guide for ED Practitioners

Coordination of care for patients with neuro-ophthalmic disorders can be very challenging in the community emergency department (ED) setting. Unlike university- or tertiary hospital-based EDs, the general ophthalmologist is often not as familiar with neuro-ophthalmology and the examination of neuro-ophthalmology patients in the acute ED setting. Embracing image capturing of the fundus, using a non-mydriatic camera, may be a game-changer for communication between ED physicians, ophthalmologists, and tele-neurologists. Patient care decisions can now be made with photographic documentation that is then conveyed through HIPAA-compliant messaging with accurate and useful information with both ease and convenience. Likewise, external photos of the anterior segment and motility are also helpful. Finally, establishing clinical and imaging guidelines for common neuro-ophthalmic disorders can help facilitate complete and appropriate evaluation and treatment.

Technical feasibility on reception of VHRR signals from Kalpana-1 satellite in the event of contingency with the existing operational ground receiving system

National Satellite Meteorological Center (NSMC), of India Meteorological Department is performing the vital role of receiving signals of meteorological data transmitted by KALPANA-1/INSAT series of national satellites and processing the data to generate various meteorological products for monitoring meteorological, environmental and climatological conditions. The satellite signals are currently being received through a 7.5 m diameter parabolic dish antenna installed at INSAT Earth Station of IMD located at Mausam Bhawan Complex, New Delhi. In this study an attempt has been made to receive and process the VHRR signals of KALPANA-1 through a smaller (3.8m) diameter parabolic dish antenna available at earth station .The link calculations have been made to show extra 2 db margin what is theoretically required and it will be sufficient for image capturing. We had also compared the result with existing 7.5m diameter antenna and observe that quality of satellite pictures received with 3.8m diameter antenna are also equally good. The purpose of this study is to keep in operational readiness a backup antenna for the reception of KALPANA-1 in the event of any unforseen contingency with the existing 7.5m diameter parabolic dish antenna, using the existing infrastructure of IMD.

Coronavirus Spread Limitation Using Detective Smart System

Given the circumstances the world is going through due to the novel coronavirus (Covid-19); this paper proposes a new smart system that aims to reduce the spread of the virus. The proposed Covid-19 containment system is designed to be installed outside hospitals and medical centers. Additionally, it works at night as well as at daylight. The system is based on Deep Learning applied to pedestrian temperature data sets that are collected using thermal cameras. The data set is primarily of temperature of pedestrians around medical centers. The thermal cameras are paired with conventional cameras for image capturing and cross referencing the target pedestrian with an existing central database (Big Data). If target is positive, the system sends a text message to the potentially infected person's cell phone upon recognition. The advisory sent text may contain useful information such as the nearest testing or isolation facility. This proposed system is assumed to be linked with the bigger network of the country’s Covid-19 response efforts. The simulation results reveal that the system can achieve an average precision of 90% fever detection among pedestrians.

Virtual Crime Scene Investigation and Evidence Protection

This paper presents the recreation of crime scenes through Virtual Reality for crime investigation and evidence storage. 3D image capturing and processing techniques are used to render fully-immersive Virtual Reality environment for investigators to work with. Cloud database and Blockchain technology for evidence storage are explained. The different levels of views on such virtual crime scenes and evidence storage are also expounded.