A novel virtual four-ocular stereo vision system based on single camera for measuring insect motion parameters

A novel virtual four-ocular stereo measurement system based on single high speed camera is proposed for measuring double beating wings of a high speed flapping insect. The principle of virtual monocular system consisting of a few planar mirrors and a single high speed camera is introduced. The stereo vision measurement principle based on optic triangulation is explained. The wing kinematics parameters are measured. Results show that this virtual stereo system not only decreases system cost extremely but also is effective to insect motion measurement.

Portable device for the local three-dimensional deformation measurement using a single camera

The aim of this paper is to establish and validate a portable device for the local three dimensional deformation measurements using a single camera combined with a triangular prism mirror and two mirrors. The mirrors were utilized to convert a single camera into a stereo image system, which views a test object from two different directions and records the surface images of the test specimen on the two halves of the camera sensor in order to achieve a three-dimensional measurement. The proposed system consists of a single camera and the reflection system was integrated into a portable device to achieve a truly portable, low-cost,local three-dimensional deformation measurement, one-time calibration and easy implementation in situ. The optical design and measurement procedures to obtain the three-dimensional(3 D) deformation measurements of the proposed system were described in detail. The efficiency and precision of the proposed system were verified by measuring the displacements of a translated flat plate. As a practical application, the proposed system is used to measure the out-of-plane displacement of an aluminum circular plate with a central load. Moreover, the normal strain measurement of a plastic beam under symmetric four-point bending via an outer loading frame was also presented. The measurement results are in good accordance with the data obtained by strain gauges. The experimental results revealed that the proposed system was practicable and effective for the local three-dimensional deformation measurement. This system well-suited to both laboratory and field condition and will have significant application in the fields of engineering.

Multi-perspective digital image correlation method using a single color camera

A novel 3 D digital image correlation(DIC) system based on a single three charge-couple device(3 CCD) color camera is proposed in this paper. Images from three different perspectives are captured by a 3 CCD camera using a reflective-based pseudo-vision system. These images are then separated by the different CCD channels, and the correlation algorithm for the multi-camera DIC system is adopted to evaluate the images. Compared to the conventional multi-camera DIC system, the proposed system is much more compact. In addition, the proposed system has no loss of spatial resolution, compares to the traditional single camera DIC system. The complex surface measurement ability and the measurement accuracy is significantly improved through the use of the multi-camera DIC algorithm. The principle of the proposed system is described in detail as well as the experimental setup. A series of validation tests are performed, and the results are verified with the commercial 3 D-DIC system.

Test and Evaluation of Aviation Die Tyre Accuracy Based on Industrial Photogrammetry

According to the operational conditions of an aviation module reticule,a measurement mode is proposed,which is based on an industrial photogrammetry system,with matching by a measuring pen.Meanwhile,the factors affecting the accuracy of the measurement have been analyzed and verified by examples.The analysis is described as follows:①Along the optical axis of the camera,the error is larger than the ones in other directions using the“single camera+measuring pen”mode;②By avoiding the error along the optical axis of the camera,the accuracy of the“single camera+measuring pen”mode is better than 0.1 mm when the measuring pen is moving parallel to the optical axis.

Hyperspectral Imaging Based on Compressive Sensing: Determining Cancer Margins in Human Pancreatic Tissue <i>ex Vivo</i>, a Pilot Study

Cancer is the second-leading cause of death in the United State and surgery remains the primary treatment for most solid mass tumors. However, accurately identifying tumor margins in real-time remains a challenge. In this study, the design and testing of hyperspectral imaging (HSI) system based on a single-pixel camera engine is discussed. The primary advantage of a single pixel architecture over traditional scanning HSI techniques is its high sensitivity and potential to function at low light levels. The objective for the imaging system described here is to detect changes in the reflectance spectra of tissue and to use these differences to delineate tumor margins. This paper presents the results of a 19-patient pilot study that assesses the ability of the HSI system to use reflectance imaging to delineate adenocarcinoma tumor margins in human pancreatic tissue imaged ex vivo. Pancreatic tissue excised during pancreatectomy was imaged immediately after being sent to the pathology lab. A pathologist sectioned the tissue and placed samples into standard tissue embedding cassettes. These tissue samples were then imaged using the HSI system. After imaging, the samples were returned to the pathologist for processing and analysis. The HSI was later compared to the histological analysis. The spectral angle mapping (SAM) and support vector machine (SVM) algorithms were used to classify pixels in the HSI images as healthy or unhealthy in order to delineate margins. Good agreement between margins determined via HSI (using both SAM and SVM) and histology/white light imaging was found.