Research of Centroid Extraction for Feature Point Based on FPGA

2011 ◽  
Vol 50-51 ◽  
pp. 799-805
Author(s):  
Bing Li ◽  
Xiao Hong Liu ◽  
Wen Jing Wu

This paper focuses on the centroid extraction algorithm of feature point. We present a recognition algorithm to identify the feature point and extract centroid. This algorithm can extract the centroid of the feature point from the complex background by scanning the original image only one time. We design a hardware architecture and implement it based on FPGA. Experimental results show that it can extract the centroid coordinates exactly from the complex background in real time with low-cost hardware resources.

2011 ◽  
Vol 403-408 ◽  
pp. 570-576
Author(s):  
Yang Liu ◽  
Xiao Bo Lu

In this paper, a real-time fog detection method using a low cost b&w camera is presented. This method is based on gray histograms which would show the correspondence relationship between the gray value and the number of the pixels. Compared with foggy-free images, we notice some characteristics of foggy images, and these characteristics are also reflected in their gray histograms. Using the data from a gray histogram and a series of thresholds, we can detect whether the original image is under fog conditions. Moreover, we divide the weather conditions into three fog levels. Some experimental results and conclusions about this work are presented.


Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1662 ◽  
Author(s):  
Siyuan Liang ◽  
Weilong Zhu ◽  
Feng Zhao ◽  
Congyi Wang

With the rapid development of microelectromechanical systems (MEMS) technology, low-cost MEMS inertial devices have been widely used for inertial navigation. However, their application range is greatly limited in some fields with high precision requirements because of their low precision and high noise. In this paper, to improve the performance of MEMS inertial devices, we propose a highly efficient optimal estimation algorithm for MEMS arrays based on wavelet compressive fusion (WCF). First, the algorithm uses the compression property of the multiscale wavelet transform to compress the original signal, fusing the compressive data based on the support. Second, threshold processing is performed on the fused wavelet coefficients. The simulation result demonstrates that the proposed algorithm performs well on the output of the inertial sensor array. Then, a ten-gyro array system is designed for collecting practical data, and the frequency of the embedded processor in our verification environment is 800 MHz. The experimental results show that, under the normal working conditions of the MEMS array system, the 100 ms input array data require an approximately 75 ms processing delay when employing the WCF algorithm to support real-time processing. Additionally, the zero-bias instability, angle random walk, and rate slope of the gyroscope are improved by 8.0, 8.0, and 9.5 dB, respectively, as compared with the original device. The experimental results demonstrate that the WCF algorithm has outstanding real-time performance and can effectively improve the accuracy of low-cost MEMS inertial devices.


Author(s):  
Li-Chuan Chang ◽  
Yen-Sung Chen ◽  
Rung-Wen Liou ◽  
Chih-Hung Kuo ◽  
Chia-Hung Yeh ◽  
...  

2013 ◽  
Vol 284-287 ◽  
pp. 3178-3183 ◽  
Author(s):  
Chun Wei Lu ◽  
Chih Lung Lin ◽  
Kuo Chin Fan ◽  
Hsu Yung Cheng ◽  
Chang Jung Juan

This paper presents a reliable and robust palmprint verification approach using palmprint feature point number (FPN). The feature verified by support vector machine (SVM). It has the advantages of capturing palm images in peg-less scenarios and by a low cost and low-resolution (100dpi) digital scanner. The low-resolution images lead a less database size. There are 4800 palmprint images were collected from 160 persons to verify the validity of the proposed approach and the results are satisfactory with 98.30% classification correct rate (CCR). Experimental results demonstrate that the proposed approach is feasible and effective in palmprint verification. Our findings will help to extend palmprint verification technologies to security access control systems.


2021 ◽  
Author(s):  
Linghui Xu ◽  
Jiansong Chen ◽  
Fei Wang ◽  
Yuting Chen ◽  
Wei Yang ◽  
...  

Abstract Background: Pathological gaits of children may lead to terrible diseases, such as osteoarthritis or scoliosis. By monitoring the gait pattern of a child, proper therapeutic measures can be recommended to avoid the terrible consequence. However, low-cost systems for pathological gait recognition of children automatically have not been on market yet. Our goal was to design a low-cost gait-recognition system for children with only pressure information.Methods: In this study, we design a pathological gait-recognition system (PGRS) with an 8 × 8 pressure-sensor array. An intelligent gait-recognition method (IGRM) based on machine learning and pure plantar pressure information is also proposed in static and dynamic sections to realize high accuracy and good real-time performance. To verifying the recognition effect, a total of seventeen children were recruited in the experiments wearing PGRS to recognize three pathological gaits (toe in, toe out, and flat) and normal gait. Children are asked to walk naturally on level ground in the dynamic section or stand naturally and comfortably in the static section. The evaluation of the performance of recognition results included stratified 10-fold cross-validation with recall, precision, and a time cost as metrics.Results: The experimental results show that all of the IGRMs have been identified with a practically applicable degree of average accuracy either in the dynamic or static section. Experimental results indicate that the IGRM has 92.41% and 97.79% recognition accuracy respectively in the static and dynamic sections. And we find methods in the static section have less recognition accuracy due to the unnatural gesture of children when standing.Conclusions: In this study, a low-cost PGRS has been verified and realize feasibility, highly average precision, and good real-time performance of gait recognition. The experimental results reveal the potential for the computer supervision of non-pathological and pathological gaits in the plantar-pressure patterns of children and for providing feedback in the application of gait-abnormality rectification.


2021 ◽  
Vol 33 (4) ◽  
pp. 147-162
Author(s):  
Aleksey Yur'evich Yakushev ◽  
Yury Vital'evich Markin ◽  
Stanislav Alexandrovich Fomin ◽  
Dmitry Olegovich Obydenkov ◽  
Boris Vladimirovich Kondrat’ev

One of the most common ways documents leak is taking a picture of document displayed on the screen. For investigation of such cases data leakage prevention technologies including screen watermarking are used. The article gives short review on the problem of screen shooting watermarking and the existing research results. A novel approach for watermarking text images displayed on the screen is proposed. The watermark is embedded as slight changes in luminance into the interline spacing of marked text. The watermark is designed to be invisible for human eye but still able to be detected by digital camera. An algorithm for extraction of watermark from the screen photo is presented. The extraction algorithm doesn’t need the original image of document for successful extraction. The experimental results show that the approach is robust against screen-cam attacks, that means that the watermark stays persistent after the process of taking a photo of document displayed on the screen. A criterion for watermark message extraction accuracy without knowledge about the original message is proposed. The criterion represents the probability that the watermark was extracted correctly.


Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1176
Author(s):  
Joohyuk Yum ◽  
Jin-Sung Kim ◽  
Hyuk-Jae Lee

This paper proposes a new ASIFT hardware architecture that processes a Video Graphics Array (VGA)-sized (640 × 480) video in real time. The previous ASIFT accelerator suffers from low utilization because affine transformed images are computed repeatedly. In order to improve hardware utilization, the proposed hardware architecture adopts two schemes to increase the utilization of a bottleneck hardware module. The first is a prior anti-aliasing scheme, and the second is a prior down-scaling scheme. In the proposed method, 1 × 1 and 0.5 × 1 blurred images are generated and they are reused for creating various affine transformed images. Thanks to the proposed schemes, the utilization drop by waiting for the affine transform is significantly decreased, and consequently, the operation speed is increased substantially. Experimental results show that the proposed ASIFT hardware accelerator processes a VGA-sized video at the speed of 28 frames/s, which is 1.36 times faster than that of previous work.


2012 ◽  
Vol 562-564 ◽  
pp. 119-122 ◽  
Author(s):  
Ji Li Lu ◽  
Ming Xing Lin

In this paper, we present a design of a real-time computer vision system for polyurethane plate cutting line positioning and defects detection. The main defect of polyurethane plate is uneven texture which doesn’t meet the product requirements. We translate the original image to gray image and find the points with strongest gray as the cutting line, extract feathers and detect defects. The experimental results show that it is easy and effective to position cutting points and find defects of polyurethane plate, which can meet the requirements of production and has great practical value.


Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4976 ◽  
Author(s):  
Kaitao Meng  ◽  
Deshi Li  ◽  
Xiaofan He  ◽  
Mingliu Liu  ◽  
Weitao Song 

Recently, unmanned aerial vehicles (UAVs) have attracted much attention due to their on-demand deployment, high mobility, and low cost. For UAVs navigating in an unknown environment, efficient environment representation is needed due to the storage limitation of the UAVs. Nonetheless, building an accurate and compact environment representation model is highly non-trivial because of the unknown shape of the obstacles and the time-consuming operations such as finding and eliminating the environmental details. To overcome these challenges, a novel vertical strip extraction algorithm is proposed to analyze the probability density function characteristics of the normalized disparity value and segment the obstacles through an adaptive size sliding window. In addition, a plane adjustment algorithm is proposed to represent the obstacle surfaces as polygonal prism profiles while minimizing the redundant obstacle information. By combining these two proposed algorithms, the depth sensor data can be converted into the multi-layer polygonal prism models in real time. Besides, a drone platform equipped with a depth sensor is developed to build the compact environment representation models in the real world. Experimental results demonstrate that the proposed scheme achieves better performance in terms of precision and storage as compared to the baseline.


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