- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Power Efficiency Figure of Merit for Image Sensors
摘要： A new figure of merit (FoM) is developed with a theory, which enables the comparison of power efficiency of different image sensors based only on the pixel array size, frame rate, and total power consumption. The mathematical foundation of the FoM is provided, enabling the application of FoM to a generic image sensor supporting various read-out configurations. The model assumes a nonlinear relationship between the power consumption and operating frequency of building blocks, and the nonlinear factor is numerically derived based on the analytical modeling of image sensors. The FoM is applied to the studies from 1999 to 2018, which clarifies the trend of improvement as well as visualizes several breakthroughs in the development history.
关键词： modeling,CMOS image sensor (CIS),power efficiency,figure of merit (FoM),power consumption
更新于2025-09-23 15:23:52
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CMOS image sensor for high speed and low latency eye tracking
摘要： Eye tracking, or detecting where the user is looking at, is expected as a new type of user interfaces, with including the phenomenon of rapid eye movement, so called saccade. However, real-time tracking of saccade is difficult with the conventional image processing systems for their long processing time and latency against the speed of saccade. In this paper, we describe the design of the CMOS image sensor for eye tracking with high speed and low latency capability, as well as its evaluation results.
关键词： saccade,CMOS image sensor,column parallel architecture,eye tracking
更新于2025-09-23 15:23:52
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The Optical Barcode Detection and Recognition Method Based on Visible Light Communication Using Machine Learning
摘要： Visible light communication (VLC) has developed rapidly in recent years. VLC has the advantages of high confidentiality, low cost, etc. It could be an effective way to connect online to offline (O2O). In this paper, an RGB-LED-ID detection and recognition method based on VLC using machine learning is proposed. Different from traditional encoding and decoding VLC, we develop a new VLC system with a form of modulation and recognition. We create different features for different LEDs to make it an Optical Barcode (OBC) based on a Complementary Metal-Oxide-Semiconductor (CMOS) senor and a pulse-width modulation (PWM) method. The features are extracted using image processing and then support vector machine (SVM) and artificial neural networks (ANN) are introduced into the scheme, which are employed as a classifier. The experimental results show that the proposed method can provide a huge number of unique LED-IDs with a high LED-ID recognition rate and its performance in dark and distant conditions is significantly better than traditional Quick Response (QR) codes. This is the first time the VLC is used in the field of Internet of Things (IoT) and it is an innovative application of RGB-LED to create features. Furthermore, with the development of camera technology, the number of unique LED-IDs and the maximum identifiable distance would increase. Therefore, this scheme can be used as an effective complement to QR codes in the future.
关键词： CMOS image sensor,machine learning,image processing,RGB-LED,visible light communication (VLC)
更新于2025-09-23 15:22:29
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Compact Real-Time Inter-Frame Histogram Builder for 15Bits High-Speed ToF-Imagers based on Single-Photon Detection
摘要： Time-of-flight image sensors based on single-photon detection, i.e. SPADs, require some filtering of pixel readings. Accurate depth measurements are only possible if the jitter of the detector is mitigated. Moreover, the time stamp needs to be effectively separated from uncorrelated noise such as dark counts and background illumination. A powerful tool for this is building a histogram of a number of pixel readings. Future generation of ToF imagers are seeking to increase spatial and temporal resolution along with the dynamic range and frame rate. Under these circumstances, storing the complete histogram for every pixel becomes practically impossible. Considering that most of the information contained by the histogram represents noise, we propose a highly efficient method to store just the relevant data required for ToF computation. This method makes use of the shifted inter-frame histogram (SifH). It requires a memory as low as 128 times smaller than storing the complete histogram if the pixel values are coded on up to 15 bits. Moreover, a fixed 28 words memory is enough to process histograms containing up to 215 bins. In exchange, the overall frame rate only decreases to one half. The hardware implementation of this algorithm is presented. Its remarkable robustness for a low SNR of the ToF estimation is demonstrated by Matlab simulations and FPGA implementation using input data from a SPAD camera prototype.
关键词： shifted inter-frame histogram (SifH),single-photon avalanche-diode (SPAD),real-time time-of-flight (ToF) estimation,ToF image sensor
更新于2025-09-23 15:22:29
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Simplified Vehicle Vibration Modeling for Image Sensor Communication
摘要： Image sensor communication (ISC), derived from visible light communication (VLC) is an attractive solution for outdoor mobile environments, particularly for intelligent transport systems (ITS). In ITS-ISC, tracking a transmitter in the image plane is critical issue since vehicle vibrations make it difficult to select the correct pixels for data reception. Our goal in this study is to develop a precise tracking method. To accomplish this, vehicle vibration modeling and its parameters estimation, i.e., representative frequencies and their amplitudes for inherent vehicle vibration, and the variance of the Gaussian random process representing road surface irregularity, are required. In this paper, we measured actual vehicle vibration in a driving situation and determined parameters based on the frequency characteristics. Then, we demonstrate that vehicle vibration that induces transmitter displacement in an image plane can be modeled by only Gaussian random processes that represent road surface irregularity when a high frame rate (e.g., 1000 fps) image sensor is used as an ISC receiver. The simplified vehicle vibration model and its parameters are evaluated by numerical analysis and experimental measurement and obtained result shows that the proposed model can reproduce the characteristics of the transmitter displacement sufficiently.
关键词： vehicle motion model,vehicle vibration,visible light communication,image sensor communication,road surface irregularity,transmitter displacement
更新于2025-09-23 15:22:29
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Noise Estimation for Image Sensor Based on Local Entropy and Median Absolute Deviation
摘要： Noise estimation for image sensor is a key technique in many image pre-processing applications such as blind de-noising. The existing noise estimation methods for additive white Gaussian noise (AWGN) and Poisson-Gaussian noise (PGN) may underestimate or overestimate the noise level in the situation of a heavy textured scene image. To cope with this problem, a novel homogenous block-based noise estimation method is proposed to calculate these noises in this paper. Initially, the noisy image is transformed into the map of local gray statistic entropy (LGSE), and the weakly textured image blocks can be selected with several biggest LGSE values in a descending order. Then, the Haar wavelet-based local median absolute deviation (HLMAD) is presented to compute the local variance of these selected homogenous blocks. After that, the noise parameters can be estimated accurately by applying the maximum likelihood estimation (MLE) to analyze the local mean and variance of selected blocks. Extensive experiments on synthesized noised images are induced and the experimental results show that the proposed method could not only more accurately estimate the noise of various scene images with different noise levels than the compared state-of-the-art methods, but also promote the performance of the blind de-noising algorithm.
关键词： additive white Gaussian noise,local gray statistic entropy,image sensor,Poisson-Gaussian noise,noise estimation,local median absolute deviation
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE Asian Solid-State Circuits Conference (A-SSCC) - Tainan, Taiwan (2018.11.5-2018.11.7)] 2018 IEEE Asian Solid-State Circuits Conference (A-SSCC) - A 137-μW Area-Efficient Real-Time Gesture Recognition System for Smart Wearable Devices
摘要： Gesture recognition has increasingly become one of the most popular human-machine interaction techniques for smart devices. Existing gesture recognition systems suffer from either excessive power consumption or large size, limiting their applications for ultra-low power IoT and wearable devices. This paper presents an accurate, area-efficient, and ultra-low power real-time gesture recognition system for smart wearable devices. The proposed work utilizes a peak-based gesture classification engine with less memory and a low-resolution and low-power on-chip image sensor for achieving high area efficiency and low power. The feature extraction architecture removes fixed-pattern noises from the low-power on-chip image sensor for accuracy improvement and employs parallelism for recognition speed enhancement. The proposed system requires only 3.2 KB on-chip memory for processing 32x32 pixel data. Measurement results of a test chip fabricated in 65nm CMOS demonstrate that the proposed system consumes 137.0 pW at 0.8 V and 30fps while occupying only 1.78mm2, which achieves the lowest power and smallest area among existing gesture recognition systems.
关键词： system on chip,low power processor,image sensor,wearable devices,gesture recognition,feature extraction
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - Krakow, Poland (2018.10.16-2018.10.18)] 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - Extraction of Disparity Information Using Pixels with Integrated Apertures
摘要： In this paper, extraction of disparity information using pixels with integrated apertures is presented. In general, the aperture of a camera is located over the camera lens. However, we propose the integration of apertures on the pixels of a CMOS image sensor. The integrated apertures are designed and fabricated using a metal layer of the CMOS image sensor process and the parameters including width and offset of the integrated apertures are optimized through optical simulation. The offset of the integrated aperture is defined as the distance between the center of the pixel and the center of the integrated aperture in a unit pixel. The optical simulation is based on a finite-difference time-domain method. Based on the optical simulation, the proposed image sensor with integrated apertures was fabricated using the CMOS image sensor process. The disparity information of the images is extracted using the fabricated image sensor and the performance of this sensor is evaluated through experiments.
关键词： CMOS,image sensor,integrated aperture,disparity information
更新于2025-09-23 15:22:29
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43- and 50-Mp High-Performance Interline CCD Image Sensors
摘要： This paper describes the design and performance of two new high-resolution interline charge-coupled device image sensors for use in industrial, machine vision, and aerial photography applications. These sensors feature 4.5-μm pixels, 4 outputs, fast dump gate, horizontal lateral overflow drain, and vertical electronic shutter. The 43-Mp sensor has a 35-mm optical format and the 50-Mp sensor has a larger format with a 2.175:1 aspect ratio that matches many modern mobile phone displays. This paper discusses the challenges and solutions to manufacture such large sensors with superior image quality such as uniformity, read noise, dark current, smear, transfer gate blooming, lag, and so on.
关键词： dark current,lithography stitching,interline transfer (IT),stepper,multiple outputs,image sensor,large format,charge-coupled device (CCD),smear,Blooming
更新于2025-09-23 15:22:29
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[IEEE 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Kyoto, Japan (2018.7.9-2018.7.13)] 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Recent progress in development of radiation tolerant image sensor with field emitter array
摘要： A prototype image sensor is developed using cadmium telluride-based photodiode and a volcano-structured FEA. Radiation tolerance of each component was tested by irradiating gamma-ray using cobalt-60 source. Gamma-ray tolerance of up to 1.2 MGy was confirmed for both FEA and photodiode.
关键词： Radiation tolerant,Image sensor,Cadmium telluride (CdTe),Field emitter array (FEA)
更新于2025-09-23 15:21:21