ARTICLE | doi:10.20944/preprints201711.0021.v1
Subject: Engineering, Control And Systems Engineering Keywords: calibration; binocular vision sensor; unknown-sized elliptical stripe
Online: 2 November 2017 (17:37:06 CET)
Most of the existing calibration methods for binocular stereo vision sensor (BSVS) depend on high-accuracy target with feature points that are difficult to manufacture and costly. In complex light conditions, optical filters are used for BSVS, but they affect imaging quality. Hence, the use of a high-accuracy target with certain-sized feature points for calibration is not feasible under such complex conditions. To solve these problems, a calibration method based on unknown-sized elliptical stripe images is proposed. With known intrinsic parameters, the proposed method adopts the elliptical stripes located on the parallel planes as a medium to calibrate BSVS online. In comparison with the common calibration methods, the proposed method avoids utilizing high-accuracy target with certain-sized feature points. Therefore, the proposed method is not only easy to implement but is a realistic method for the calibration of BSVS with optical filter. Changing the size of elliptical curves projected on the target solves the difficulty of applying the proposed method in different fields of view and distances. Simulative and physical experiments are conducted to validate the efficiency of the proposed method. When the field of view is approximately 400 mm × 300 mm, the proposed method can reach a calibration accuracy of 0.03 mm, which is comparable with that of Zhang’s method.
ARTICLE | doi:10.20944/preprints202310.0444.v1
Subject: Computer Science And Mathematics, Computer Vision And Graphics Keywords: Monocular Vision; Binocular Vision; Forward Projection; Inverse Projection; Displacement Projection
Online: 8 October 2023 (10:19:31 CEST)
A human eye has about 120 million rod cells and 6 million cone cells. This huge number of light sensing cells inside a human eye will continuously produce a huge quantity of visual signals which flow into a human brain for daily processing. However, the real-time processing of these visual signals does not cause any fatigue to a human brain. This fact tells us the truth which is to say that human-like vision processes do not rely on complicated formulas to compute depth, displacement, and colors, etc. On the other hand, a human eye is like a PTZ camera. Here, PTZ stands for pan, tilt and zoom. We all know that in computer vision, each set of PTZ parameters (i.e., coefficients of pan, tilt and zoom) requires a dedicated calibration to determine a camera’s projection matrix. Since there is an infinite number of PTZ parameters which could be produced by a human eye, it is unlikely that a human brain stores an infinite number of calibration matrices for each human eye. Therefore, it is an interesting question for us to answer, which is to say whether simpler formulas of computing depth and displacement exist or not. Moreover, these formulas must be calibration friendly (i.e., easy process on the fly or on the go). In this paper, we disclose an important discovery of a new solution to 3D projection in a human-like binocular vision system. The purpose of doing 3D projection in binocular vision is to undertake forward and inverse transformations (or mappings) between coordinates in 2D digital images and coordinates in a 3D analogue scene. The formulas underlying the new solution are accurate, easily computable, easily tunable (i.e., to be calibrated on the fly or on the go) and could be easily implemented by a neural system (i.e., a network of neurons). Experimental results have validated the discovered formulas.
ARTICLE | doi:10.20944/preprints202112.0349.v2
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: yak; semantic segmentation; binocular vision; body size; weight stimation
Online: 9 March 2022 (10:02:00 CET)
In order to solve the labor-intensive and time-consuming problem in the process of measuring yak body ruler and weight in yak breeding industry in Qinghai Province, a non-contact method for measuring yak body ruler and weight was proposed in this experiment, and key technologies based on semantic segmentation, binocular ranging and neural network algorithm were studied to boost the development of yak breeding industry in Qinghai Province. Main conclusions: (1) Study yak foreground image extraction, and implement yak foreground image extraction model based on U-net algorithm; select 2263 yak images for experiment, and verify that the accuracy of the model in yak image extraction is over 97%. (2) Develop an algorithm for estimating yak body ruler based on binocular vision, and use the extraction algorithm of yak body ruler related measurement points combined with depth image to estimate yak body ruler. The final test shows that the average estimation error of body height and body oblique length is 2.6%, and the average estimation error of chest depth is 5.94%. (3) Study the yak weight prediction model; select the body height, body oblique length and chest depth obtained by binocular vision to estimate the yak weight; use two algorithms to establish the yak weight prediction model, and verify that the average estimation error of the model for yak weight is 10.7% and 13.01% respectively.
ARTICLE | doi:10.20944/preprints201608.0186.v1
Subject: Computer Science And Mathematics, Geometry And Topology Keywords: active vision; the conformal camera; the Riemann sphere; Möbius geometry; complex projective geometry; projective Fourier transform; retinotopy; binocular vision; horopter
Online: 20 August 2016 (11:24:25 CEST)
Primate vision is an active process that constructs a stable internal representation of the 3D world based on 2D sensory inputs that are inherently unstable due to incessant eye movements. We present here a mathematical framework for processing visual information for a biologically-mediated active vision stereo system with asymmetric conformal cameras. This model utilizes the geometric analysis on the Riemann sphere developed in the group-theoretic framework of the conformal camera, thus far only applicable in modeling monocular vision. The asymmetric conformal camera model constructed here includes the fovea’s asymmetric displacement on the retina and the eye’s natural crystalline lens tilt and decentration, as observed in ophthalmological diagnostics. We extend the group-theoretic framework underlying the conformal camera to the stereo system with asymmetric conformal cameras. Our numerical simulation shows that the 1 theoretical horopter curves in this stereo system are conics that well approximate the empirical longitudinal horopters of the primate vision system.
ARTICLE | doi:10.20944/preprints202305.1746.v1
Subject: Computer Science And Mathematics, Computer Vision And Graphics Keywords: improved Yolov5; opencv; urban stagnant water,binocular ranging principle
Online: 25 May 2023 (05:49:48 CEST)
In recent years, since flood disasters have brought immeasurable losses to the city, it is urgent to prevent and solve the flood of stagnant water. Considering the shortage of real-time and accuracy of hydrological analysis, Opencv technology is used in this paper to process the obtained data in real time. For improved Yolov5, BoTNet and GAMAttention Transformer are used to improve Yolov5 to enhance its ability of recognition and prediction to better identify surface gathered water. The prediction rate of the improved Yolov5 is 7.1% higher than that of Yolov7 and 1.7% higher than that of Yolov5.After that, contour preprocessing of the image is carried out through the cropping technology of the identification frame to eliminate relatively unstable factors. The principle of binocular distance measurement is used to measure the three-dimensional coordinates of the actual distance, better constrain the contour proportion of the picture, and then the Opencv technology is used to get the outline of the water, and HSV is combined with better color processing pictures for the identification of the water and contour generation, and the area is obtained to correspond to the corresponding parameters of flood to provide important help in flood prevention and storm drainage.
ARTICLE | doi:10.20944/preprints202310.1745.v1
Subject: Engineering, Civil Engineering Keywords: binocular vision; bridge swivel construction; brace displacement; mark point matching
Online: 26 October 2023 (18:56:36 CEST)
To solve the problem of complex sensor installation and easy damage in contact displacement measurement, a non-contact measurement method of brace displacement in bridge swivel construction based on binocular vision is proposed in this study. Combined with monitoring data in a swivel construction interchange project, binocular vision system was compared and analyzed with the traditional displacement meter and total station. Results showed that force versus displacement variation plots were obtained by binocular visual measurement in the weighing test, the inflection point can be clearly distinguished, and the position of the inflection point was the same as that of the displacement meter; monitoring data of binocular vision measurement and total station were compared and analyzed in the bridge swivel process, the average error was no more than 0.18 mm, the maximum error was no more than 0.42 mm, and the standard deviation was no more than 0.12. The method proposed in this study can be used as an alternative to displacement meter and total station measurement methods in bridge swivel construction, the problem of complex sensor installation and easy damage is solved in brace displacement measurement, equipment and labor costs can be effectively saved.
ARTICLE | doi:10.20944/preprints202104.0282.v1
Subject: Computer Science And Mathematics, Computer Science Keywords: OpenCV stereo-vision; low-cost stereo-vision; do it yourself stereo-vision; stereoscopic binocular vision; binocular vision; do it yourself stereo-vision; practical guide stereo-vision
Online: 12 April 2021 (12:09:38 CEST)
The paper presents an analysis of the latest developments in the field of stereo vision in the low-cost segment, both for prototypes and for industrial designs. We described the theory of stereo vision and presented information about cameras and data transfer protocols and their compatibility with various devices. The theory in the field of image processing for stereo vision processes is considered and the calibration process is described in detail. Ultimately, we presented the developed stereo vision system and provided the main points that need to be considered when developing such systems. The final, we presented software for adjusting stereo vision parameters in real-time in the python language in the Windows operating system.
ARTICLE | doi:10.20944/preprints202304.0204.v1
Subject: Medicine And Pharmacology, Otolaryngology Keywords: Tullio Phenomena; Noise Cancellation Device; Dizziness; Vertical Heterophoria; Third Mobile Window Disorder; Binocular Vision Dysfunction
Online: 11 April 2023 (05:49:05 CEST)
Identifying a vestibular source of pathology in patients complaining of post-traumatic brain injury (TBI) dizziness can be difficult. We describe a possible new method utilizing the reduction of post-TBI symptom (including dizziness) with the use of a noise cancellation device (NCD). This retrospective case series included patients with TBI and dizziness presenting to a binocular vision specialty clinic, who were diagnosed with a vertical heterophoria (VH). If they did not respond adequately to microprism lenses and/or if they experienced hyperacusis, they were evaluated with an NCD. If there was marked reduction of TBI symptoms (including dizziness), the patients were referred to a neuro-otologist for vestibular diagnostic evaluation and treatment. Fourteen patients were identified and found to have abnormalities on vestibular testing consistent with Third Mobile Window Disorder (TMWD). All were treated with a 6-week medical protocol (diuretics, no straining, low sodium/no caffeine diet). Five responded positively, requiring no further treatment. Nine required surgical intervention and responded positively. In conclusion, 14 patients with post-concussive dizziness and VH, a positive response to NCD was associated with abnormal vestibular testing, a diagnosis of TMWD, and symptom reduction/resolution with a medical or surgical approach. The removal of sound resulting in reduction or resolution of vestibular symptoms represents an Inverse Tullio Phenomena.