In order to realize high contrast imaging with portable devices for potential mobile healthcare, we demonstrate a hand-held smartphone based quantitative phase microscope using the transport of ...intensity equation method. With a cost-effective illumination source and compact microscope system, multi-focal images of samples can be captured by the smartphone's camera via manual focusing. Phase retrieval is performed using a self-developed Android application, which calculates sample phases from multi-plane intensities via solving the Poisson equation. We test the portable microscope using a random phase plate with known phases, and to further demonstrate its performance, a red blood cell smear, a Pap smear and monocot root and broad bean epidermis sections are also successfully imaged. Considering its advantages as an accurate, high-contrast, cost-effective and field-portable device, the smartphone based hand-held quantitative phase microscope is a promising tool which can be adopted in the future in remote healthcare and medical diagnosis.
The warhead fragments formed by projectile proximity explosion are easily occluded and coincided at the same time, it is very difficult to identify the spatial position of each warhead fragment, ...which will affect the analysis and research of the launching performance of weapons. To obtain dynamic parameter of each warhead fragment, this article proposes a new measurement method by using two light field cameras with micro‐lens array imaging, establishes the spatial position calculation model of warhead fragment, researches the spatial position recognition algorithm of warhead fragment, gives the calculation function of the depth value of the warhead fragment based on digital refocusing principle of light field camera. According to the depth information of the warhead fragment in the optical imaging region, sets up the recognition model and provides the processing algorithm of multiple warhead fragments occlusion and coincidence. In accordance with the spatial position calculation function of warhead fragment, utilizes the differential method to analyze the testing error. Through simulation and experimental analysis, the results of simulation and contrastive testing show that the proposed method can effectively recognize and distinguish the occlusive warhead fragments, which makes up for the shortcomings of the traditional binocular vision testing method.
We designed a portable Raspberry Pi-based spectrometer, which mainly consists of a white LED acting as the wide-spectrum source, a reflection grating for light dispersion, and a CMOS imaging chip ...aiming at spectral recording. All the optical elements and Raspberry Pi were integrated using 3-D printing structures with a size of 118 mm × 92 mm × 84 mm, and home-built software was also designed for spectral recording, calibration, analysis, and display implemented with a touch LCD. Additionally, the portable Raspberry Pi-based spectrometer was equipped with an internal battery, thus supporting on-site applications. Tested by a series of verifications and applications, the portable Raspberry Pi-based spectrometer could reach a spectral resolution of 0.065 nm per pixel within the visible band and provide spectral detection with high accuracy. Therefore, it can be used for on-site spectral testing in various fields.
A portable Raspberry Pi-based spectrometer with a size of 118 mm × 92 mm × 84 mm and home-built software has been designed. It could reach a high spectral resolution within the visible band and provide spectral detection with high accuracy.
In dynamic scene monocular visual SLAM, it is important to recognize static object imaging features for mapping. The optical flow of noise and the object moving in the same orientations would have ...the same orientations of static feature for two frames image, that would disturb static feature point recognition. Because the translational motion optical flow orientations method judges with optical flow of single feature point and translational motion orientations, it is not reliable for static feature point recognition. Therefore, a 3D motion segmentation combined for static object imaging features recognition is proposed, which clusters the same optical flow of feature points in 3D motion subspace, including orientations and amplitude of translation and rotation. The simulation results show that the proposed static object imaging features recognition method improves the recognition correct rate and reliability of static features. So, it is effective for static object imaging features recognition in dynamic scene mapping.
For the moving state of armored vehicle, the random rendezvous of rotary scanning optical imaging system and armored vehicle will be in an uncertain state, which makes the target information detected ...by the system floated and the reliable target signal hardly obtain. In this article, the target detection radiation characteristic distribution of the system and the calculation method of the geometric parameters of optical scanning in the random rendezvous state are obtained. An optical scanning detection calculation method for air‐ground armored targets is presented under space‐time correlation condition. According to the characteristic of rotary scanning optical imaging system caused by the thermal radiation of armored vehicles, a model of infrared radiation characteristic distribution of armored vehicles is established form the relationship between the system and armored targets. Combining with the established air‐ground rotation optical imaging‐scanning model, the contribution of Infrared Radiation to the optical imaging sensor during the movement of armored vehicles in different states and the calculation function of the output signal of the sensor are given respectively. Through calculation and experiment, it is found that the armored targets can be effectively detected within detection zone that the detection height is less than 35 m, the area of the radiation characteristic area is more than 1 m2 and the detection angle is 20 ° : 40°. The moving direction and contour size of the target can be distinguished by the rendezvous angle difference and the response time of the signal response time of the central.
General target detection system is based on active detection method, which is usually of poor concealment and bulky. In order to improve the concealment and dexterity of airborne detection, an ...airborne infrared scanning imaging system for ground vehicles based on passive infrared detection is proposed. In order to solve the problem of false alarm and false recognition when the rotary airborne multi-element infrared detection is used to identify armored vehicles on the ground, based on the wavelet theory, the infrared signal output from the air to ground rotary detection system is de noised by wavelet. The denoising threshold function suitable for the rotating multi element infrared detection system is constructed. Through calculation analysis and experimental verification, the fours-layer coif wavelet basis function is the best. On the premise of not losing the infrared information of the original armored vehicle target, the output waveform is flat when there is no armored vehicle, and the output waveform is smooth when there is armored vehicle target. It provides a theoretical basis for the later realization of armored vehicle type identification.
The key challenge in RBGT tracking is how to fuse dual‐modality information to build a robust RGB‐T tracker. Motivated by CNN structure for local features, and visual transformer structure for global ...representations, the authors propose a two‐stream hybrid structure, termed CMC2R, to take advantage of convolutional operations and self‐attention mechanisms to lean the enhanced representation. CMC2R fuses local features and global representations under different resolutions through the transformer layer of the encoder block, and the two modalities are collaborated to get contextual information by the spatial and channel self‐attention. The temporal association is performed with the track query, each track query models the entire track of an object, and updated frame‐by‐frame to build the long‐range temporal relation. Experimental results show the effectiveness of the proposed method, and achieve the SOTAs performance.
Part‐MOT, a one‐stage anchor‐free architecture which unifies the object identification representation and detection in one task for visual object tracking is presented. For object representation, a ...position relevant feature is obtained using the center‐ness information, which takes advantage of the anchor‐free ideal to encode the feature map as the instance‐aware embedding. To adapt to the object's movement, the clustering‐based method to get the global instance feature is introduced. This enables this approach more robust to make better tracking decisions. Part‐MOT achieves the state‐of‐the‐art performance on public datasets, with especially strong results for object deformation and movement changes.
Though relatively good effect has been achieved by the image de‐blurring method based on deep learning, the existing methods still suffer from the problem of unclear restoration of the edges. ...Therefore, brain‐inspired image restoration model based on human attention and “fine vision” is proposed to improve the blind restoration quality of the image in this paper according to the response mechanism of the different cerebral cortices for high and low spatial resolutions. The designed brain‐inspired model consists of dual‐channel network available to realize the function of feature merger for low and high resolutions, which is used to extract the image edges with detailed information filtered out. Confirmatory experiment is implemented based on the blurred image in the data set of GOPRO, LIVE and set14. As per the result, the model proposed is available for relatively good restoration of blurred image and super‐resolution, as well as looking results by visual inspection.
The distribution characteristics of a warhead fragment field formed by projectile proximity explosion constitute an important factor that affects the damage of spatial target. In this study, the ...relationship between the warhead fragment spatial parameters and the damaged target was established. Damage efficiency of projectile proximity explosion to target under the intersection condition of multi-posture warhead fragment and damaged target was investigated. Furthermore, by utilizing the relative spatial coordinate transformation relationship between warhead fragment and damaged target a calculation model for damage element hitting damaged target position was established. Moreover, herein the calculation function of the damaged area of the damaged target under different intersection postures was obtained after projectile proximity explosion, and finally the calculation model of the damage probability of the warhead fragment to the damaged target was derived. Through theoretical calculation and experimental analysis, the correlation relationship between the distribution parameters of the warhead fragments and the spatial position coordinates of the damaged target was analyzed. Based on the explosion point and warhead fragment parameters obtained using the multiple screens testing system, and then by using spatial coordinate matrix to carry out the corresponding calculation, the parameters of the system software were provided, the damage results of the target under the follow-up state of projectile proximity explosion were obtained, and the effectiveness and accuracy of the established target damage assessment method were verified.
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