- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Pattern Reconstructability in Fully Parallel Thinning
摘要： It is a challenging topic to perform pattern reconstruction from a unit-width skeleton, which is obtained by a parallel thinning algorithm. The bias skeleton yielded by a fully-parallel thinning algorithm, which usually results from the so-called hidden deletable points, will result in the dif?culty of pattern reconstruction. In order to make a fully-parallel thinning algorithm pattern reconstructable, a newly-de?ned reconstructable skeletal pixel (RSP) including a thinning ?ag, iteration count, as well as reconstructable structure is proposed and applied for thinning iteration to obtain a skeleton table representing the resultant thin line. Based on the iteration count and reconstructable structure associated with each skeletal pixel in the skeleton table, the pattern can be reconstructed by means of the dilating and uniting operations. Embedding a conventional fully-parallel thinning algorithm into the proposed approach, the pattern may be over-reconstructed due to the in?uence of a biased skeleton. A simple process of removing hidden deletable points (RHDP) in the thinning iteration is thus presented to reduce the effect of the biased skeleton. Three well-known fully-parallel thinning algorithms are used for experiments. The performances investigated by the measurement of reconstructability (MR), the number of iterations (NI), as well as the measurement of skeleton deviation (MSD) con?rm the feasibility of the proposed pattern reconstruction approach with the assistance of the RHDP process.
关键词： skeleton,image processing,reconstructable skeletal pixel (RSP),thinning,hidden deletable point (HDP),pattern reconstruction
更新于2025-09-23 15:21:21
-
Variety Identification of Raisins Using Near-Infrared Hyperspectral Imaging
摘要： Different varieties of raisins have different nutritional properties and vary in commercial value. An identification method of raisin varieties using hyperspectral imaging was explored. Hyperspectral images of two different varieties of raisins (Wuhebai and Xiangfei) at spectral range of 874–1734 nm were acquired, and each variety contained three grades. Pixel-wise spectra were extracted and preprocessed by wavelet transform and standard normal variate, and object-wise spectra (sample average spectra) were calculated. Principal component analysis (PCA) and independent component analysis (ICA) of object-wise spectra and pixel-wise spectra were conducted to select effective wavelengths. Pixel-wise PCA scores images indicated differences between two varieties and among different grades. SVM (Support Vector Machine), k-NN (k-nearest Neighbors Algorithm), and RBFNN (Radial Basis Function Neural Network) models were built to discriminate two varieties of raisins. Results indicated that both SVM and RBFNN models based on object-wise spectra using optimal wavelengths selected by PCA could be used for raisin variety identification. The visualization maps verified the effectiveness of using hyperspectral imaging to identify raisin varieties.
关键词： object-wise,pixel-wise,support vector machine,near-infrared hyperspectral imaging,raisins
更新于2025-09-23 15:21:21
-
[IEEE 2019 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) - Ottawa, ON, Canada (2019.7.8-2019.7.12)] 2019 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) - Simulation of quantum light sources using the self-consistently coupled Schr??dinger-Poisson-Drift-Diffusion-Lindblad syste
摘要： A very-large-scale integration capable of extracting motion features from moving images in real time has been developed employing row-parallel and pixel-parallel architectures based on the digital pixel sensor technology. Directional edge filtering of input images is carried out in row-parallel processing to minimize the chip real estate. To achieve a real-time response of the system, a fully pixel-parallel architecture has been explored in adaptive binarization of filtered images for essential feature extraction as well as in their temporal integration and derivative operations. As a result, self-speed-adaptive motion feature extraction has been established. The chip was designed and fabricated in a 65-nm CMOS technology and used to build an object detection system. Motion-sensitive target image localization was demonstrated as an illustrative example.
关键词： parallel architecture,digital pixel sensor (DPS),Block-readout scheme,motion feature extraction (MFE),vision chip
更新于2025-09-23 15:21:01
-
Single-pixel 3D reconstruction via a high-speed LED array
摘要： Three-dimensional reconstruction can be performed in many ways, among which photometric stereo is an established and intensively investigated method. In photometric stereo, geometric alignment or pixel-matching between two-dimensional images under different illuminations is crucial to the accuracy of three-dimensional reconstruction, and the dynamic of the scene makes the task difficult. In this work, we propose a single-pixel three-dimensional reconstructioning system utilizing structured illumination, which is implemented via a high-speed LED array. By performing 500kHz structured illumination and capturing the reflected light intensity with detectors at different spatical locations, two-dimensional images of different shadows with 64×64 pixel resolution are reconstructed at 122 frame per second. Three-dimensional profiles of the scene are further reconstructed using the surface gradients derived by photometric stereo algorithm, achieving a minimum accuracy of 0.50 mm. Chromatic three-dimensional imaging via an RGB LED array is also performed at 40 frame per second. The demonstrated system significantly improves the dynamic performance of the single-pixel three-dimensional reconstruction system, and offers potential solutions to many applications, such as fast three- dimensional inspection.
关键词： 3D reconstruction,LED array,single-pixel imaging
更新于2025-09-23 15:21:01
-
Operation and performance of microhexcavity pixel detector in gas discharge and avalanche mode
摘要： The Microhexcavity Panel (??Hex) is a novel gaseous micropattern particle detector comprised of a dense array of close-packed hexagonal pixels, each operating as an independent detection unit for ionizing radiation. It is a second generation detector derived from plasma panel detectors and microcavity detectors. The ??Hex is under development to be deployed as a scalable, fast timing (ns) and hermetically sealed gaseous tracking detector with high rate (> 100KHz∕cm2) capability. The devices reported here were fabricated as 16 × 16 pixel arrays of 2 mm edge-to-edge, 1 mm deep hexagonal cells embedded in a thin, 1.4 mm glass–ceramic wafer. Cell walls are metalized cathodes, connected to high voltage bus lines through conductive vias. Anodes are small, 457 μm diameter metal discs screen printed on the upper substrate. The detectors are filled with an operating gas to near 1 atm and then closed with a shut-off valve. They have been operated in both avalanche mode and gas discharge devices, producing mV to volt level signals with about 1 to 3 ns rise times. Operation in discharge mode is enabled by high impedance quench resistors on the high voltage bus at each pixel site. Results indicate that each individual pixel behaves as an isolated detection unit with high single pixel intrinsic efficiency to both ??s from radioactive sources and to cosmic ray muons. Continuous avalanche mode operation over several days at hit rates over 300 KHz∕cm2 with no gas flow have been observed. Measurements of pixel isolation, timing response, efficiency, hit rate and rate stability are reported.
关键词： Gas based radiation detectors,Particle detectors,Pixel detectors
更新于2025-09-23 15:21:01
-
Heavily Irradiated 65-nm Readout Chip With Asynchronous Channels for Future Pixel Detectors
摘要： This paper discusses the main results relevant to the characterization of an analog front-end processor designed in view of experiments with unprecedented particle rates and radiation levels at the high-luminosity Large Hadron Collider (HL-LHC). The front-end channel presented in this paper is part of the CHIPIX65-FE0 prototype, a readout application-speci?ed integrated circuit designed in a 65-nm CMOS technology in the frame of the CERN RD53 collaboration. The prototype integrates a 64 × 64 pixel matrix, divided into two 32 × 64 submatrices, featuring squared pixels with 50-μm pitch, embodying two analog front-end architectures based on synchronous and asynchronous hit discriminators. This paper is focused on the characterization of the array with asynchronous channels, before and after exposure to ionizing doses up to 630 Mrad(SiO2) of X-rays. The analog chain takes a per-channel area close to 1000 μm2, with a power dissipation of around 5 μW. The mean value of the equivalent noise charge, not signi?cantly affected by radiation, is close to 100 electrons with no sensor connected to the front end. The threshold dispersion before irradiation is 55 electrons, for a tuned threshold of 600 electrons, with a moderate increase after irradiation. In-pixel analog-to-digital conversion, based on the time-over-threshold technique, is not appreciably in?uenced by the radiation as well. The assessed performance guarantees sub-1000 electrons stable threshold operations, which is a mandatory feature for highly ef?cient readout chips at the HL-LHC.
关键词： pixel readout,Analog front ends,electronic noise,CMOS processes,ionizing radiation effects
更新于2025-09-23 15:21:01
-
Teleoperation system for a mobile robot arm with visual servomechanism based on turning radius determination using angle information of image
摘要： This paper considers the development of a teleoperation system for a mobile robot arm with visual servo mechanism. The robot to be operated mainly consists of a mobile robot and a robot arm with USB camera. The robot is teleoperated according to the control command which is generated by combining the manual operation with the autonomous control via the vision system based on the USB camera images. In this paper, a control method of determining the turning radius of the mobile robot is proposed based on the angle information of image corresponding to the error of a target position from the reference one. To evaluate the proposed teleoperation system, experiments of pressing a button were conducted by using an actual robot. It was verified from the experimental results that sufficiently high success rate of teleoperation could be obtained by the proposed method.
关键词： Angle-pixel characteristics,Turning radius,Teleoperation,Visual servo,Mobile robot
更新于2025-09-23 15:21:01
-
A new method of mark detection for software-based optical mark recognition
摘要： Software optical mark recognition (SOMR) is the process whereby information entered on a survey form or questionnaire is converted using specialized software into a machine-readable format. SOMR normally requires input fields to be completely darkened, have no internal labels, or be filled with a soft pencil, otherwise mark detection will be inaccurate. Forms can also have print and scan artefacts that further increase the error rate. This article presents a new method of mark detection that improves over existing techniques based on pixel counting and simple thresholding. Its main advantage is that it can be used under a variety of conditions and yet maintain a high level of accuracy that is sufficient for scientific applications. Field testing shows no software misclassification in 5695 samples filled by trained personnel, and only two misclassifications in 6000 samples filled by untrained respondents. Sensitivity, specificity, and accuracy were 99.73%, 99.98%, and 99.94% respectively, even in the presence of print and scan artefacts, which was superior to other methods tested. A separate direct comparison for mark detection showed a sensitivity, specificity, and accuracy respectively of 99.7%, 100.0%, 100.0% (new method), 96.3%, 96.0%, 96.1% (pixel counting), and 99.9%, 99.8%, 99.8% (simple thresholding) on clean forms, and 100.0%, 99.1%, 99.3% (new method), 98.4%, 95.6%, 96.2% (pixel counting), 100.0%, 38.3%, 51.4% (simple thresholding) on forms with print artefacts. This method is designed for bubble and box fields, while other types such as handwriting fields require separate error control measures.
关键词： Software optical mark recognition,pixel counting,mark detection,print and scan artefacts,simple thresholding
更新于2025-09-23 15:21:01
-
Analysis and Design of a CMOS Ultra-High-Speed Burst Mode Imager with In-Situ Storage Topology Featuring In-Pixel CDS Amplification
摘要： This paper presents an in-situ storage topology for ultra-high-speed burst mode imagers, enabling low noise operation while keeping a high frame depth. The proposed pixel architecture contains a 4T pinned photodiode, a correlated double sampling (CDS) amplification stage, and an in-situ memory bank. Focusing on the sampling noise, the system level trade-off of the proposed pixel architecture is discussed, showing its advantages on the noise, power, and scaling capability. Integrated with an AC coupling CDS stage, the amplification is obtained by exploiting the strong capacitance to the voltage relation of a single NMOS transistor. A comprehensive noise model is developed for optimizing the trade-off between the area and noise. As a proof-of-concept, a prototype imager with a 30 μm pixel pitch was fabricated in a CMOS 130 nm technology. A 108-cell memory bank is implemented allowing dense layout and parallel readout. Two types of CDS amplification stages were investigated. Despite the limited memory capacitance of 10 fF/cell, the photon transfer curves of both pixel types were measured over different operation speeds up to 20 Mfps showing a noise performance of 8.4 e?.
关键词： burst mode,million frames per second,ultra-high-speed imaging,in-pixel amplification,in-situ storage,image sensors
更新于2025-09-23 15:21:01
-
25 Gb/s Directly Modulated Widely Tunable 1.3 ??m Dual Wavelength DFB Laser for THz Communication
摘要： This paper presents a readout integrated circuit called UFXC32k, designed for hybrid pixel semiconductor detectors used in X-ray imaging applications. The UFXC32k integrated circuit, designed in a CMOS 130 nm process, contains about 50 million transistors in the area of 9.64 mm × 20.15 mm. The core of the IC is a matrix of 128 × 256 square-shaped pixels of 75 μm pitch. Each pixel contains a charge sensitive ampli?er, a shaper, two discriminators, and two 14-bit ripple counters. The analog front-end electronics allow processing of sensor signals of both polarities (holes and electrons). The UFXC32k chip is bump-bonded to a pixel silicon sensor and is fully characterized using X-ray radiation. The measured equivalent noise charge for the standard settings is equal to 123 e? rms (for the peaking time of 40 ns) and each pixel dissipates 26 μW. Thanks to the use of trim blocks working in each pixel independently, an effective off- set spread calculated to the input is only 9 e? rms with a gain spread of 2%. The maximum count rate per pixel depends mainly on effective CSA feedback resistance. Dead time in the front end can be set as low as 85 ns. In the continuous readout mode, a user can select the number of bits read out from each pixel to optimize the UFXC32k frame rate, e.g., for a readout of 2 bits/pixel with 200 MHz clock, the frame rate is equal to 23 kHz.
关键词： X-ray imaging,pixel detectors,Matching,single photon counting
更新于2025-09-23 15:19:57