Real-time Sound Detection and Regeneration Based on Optical Flow Algorithm of Laser Speckle Images

Wu, Nan; Haruyama, Shinichiro

doi:10.1109/wocc.2019.8770661

Cited by 6 publications

(5 citation statements)

References 2 publications

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“…Regarding speech reconstruction algorithm, researchers have proposed a variety of methods, including digital image correlation (DIC) [ 19 , 20 , 21 , 22 , 23 , 24 ], optical flow method [ 16 , 25 , 26 ], and intensity method [ 27 , 28 ]. Ref.…”

Section: Introductionmentioning

confidence: 99%

A Speech Enhancement Algorithm for Speech Reconstruction Based on Laser Speckle Images

Hao

Zhu

Wang

et al. 2022

Sensors

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In the optical system for reconstructing speech signals based on laser speckle images, the resonance between the sound source and nearby objects leads to frequency response problem, which seriously affects the accuracy of reconstructed speech. In this paper, we propose a speech enhancement algorithm to reduce the frequency response. The results show that after using the speech enhancement algorithm, the frequency spectrum correlation coefficient between the reconstructed sinusoidal signal and the original sinusoidal signal is improved by up to 82.45%, and the real speech signal is improved by up to 56.40%. This proves that the speech enhancement algorithm is a valuable tool for solving the frequency response problem and improving the accuracy of reconstructed speech.

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Section: Introductionmentioning

confidence: 99%

A Speech Enhancement Algorithm for Speech Reconstruction Based on Laser Speckle Images

Hao

Zhu

Wang

et al. 2022

Sensors

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“…As a first attempt of non-contact accelerometer implementation based on the laser speckle optical flow detection, the Viaxl presented in this paper can be improved in terms of bandwidth and accuracy through the hardware upgrades, such as using a camera with a high processing speed and frame rate [ 16 ]. On the other hand, improving the core algorithm of optical flow detection, such as in the waveform reconstruction of the time domain and estimation of moving direction, which have been preliminarily verified in [ 13 , 19 ], will greatly expand the application possibilities of the Viaxl system.…”

Section: Discussionmentioning

confidence: 99%

“…Viaxl uses a normal commercial camera to capture the laser speckle reflected by the moving object and calculate the ego-motion information between two adjacent frames of speckle through the optical flow algorithm, and then completes a real-time acceleration calculation. Due to the difficulty of acquiring the feature points in a speckle ( Figure 1 ), Farneback optical flow—one of the most widely used dense optical flow algorithms—is used to estimate the displacement of the speckle [ 16 ]. The core idea of the Farneback algorithm is to estimate the polynomial approximation of speckle images using the neighborhood domain information of each pixel [ 17 ].…”

Section: System Prototypementioning

confidence: 99%

Viaxl: A Solution of a Low-Cost Real-Time Visual Accelerometer Based on Laser Speckle Optical Flow Detection

Wang

Xiong

et al. 2020

Sensors

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Non-contact and non-destructive acceleration measurement is receiving considerable attention due to their low cost, flexibility, and simplicity of implementation, as well as their excellent performance in some emerging applications such as medical electronics applications, vibration monitoring, and some other special scenarios. In this paper, a visual accelerometer system based on laser speckle optical flow detection named Viaxl is proposed. Compared with the conventional non-contact acceleration measurement method based on a laser system, Viaxl has moderate and stable performance with the advantages of low cost and simplicity of implementation. Experiment results demonstrate that Viaxl, which consists of a commercial camera and a low-cost laser pointer, can achieve real-time, non-contact acceleration measurement, and confirm the basic system performance of Viaxl: a measurement nonlinearity better than 1.3%, up to 31 dB signal-to-noise ratio, and 1150 Hz theoretic bandwidth; this demonstrates the huge potential of Viaxl in a wide range of applications, and provides a new possible technical method for non-contact acceleration detection.

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“…The shift of the speckle pattern is proportional to the amount of camera defocus (i.e. L1 L2 ) [28]. Video recordings of the laser speckle pattern were processed by a motion extraction algorithm to obtain heartbeat signals.…”

Section: A Sv and Motion Extractionmentioning

confidence: 99%

Contactless Heartbeat Measurement Using Speckle Vibrometry

Que

Verkruysse

Gastel

et al. 2022

2022 44th Annual International Conference of the IEEE Engineering in Medicine &Amp; Biology Society (EMBC)

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Monitoring of heart rate in patients in the general ward is necessary to assess the clinical situation of the patient. Currently, this is done via spot-checks on pulse rate manually or on heart rate using Electrocardiogram (ECG) by nurses. More frequent measurements would allow early detection of adverse cardiac events. In this work, we investigate a contactless measurement setup combined with a signal processing pipeline, which is based on speckle vibrometry (SV), to perform contactless heart rate monitoring of human subjects in a supine position, mimicking a resting scenario in the general ward. Our results demonstrate the feasibility of extracting heart rate with SV through varying textile thicknesses (i.e., 8 mm, 32 mm and 64 mm), with an error smaller than 3 beats per minute on average compared to the ground-truth heart rate derived from ECG.*This study was approved by the ethical review board of the Eindhoven University of Technology and funded by the NWO UMOSA project (17117).

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Real-time Sound Detection and Regeneration Based on Optical Flow Algorithm of Laser Speckle Images

Cited by 6 publications

References 2 publications

A Speech Enhancement Algorithm for Speech Reconstruction Based on Laser Speckle Images

A Speech Enhancement Algorithm for Speech Reconstruction Based on Laser Speckle Images

Viaxl: A Solution of a Low-Cost Real-Time Visual Accelerometer Based on Laser Speckle Optical Flow Detection

Contactless Heartbeat Measurement Using Speckle Vibrometry

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