• Journal of Sensor Science and Technology
• /
• v.7 no.6
• /
• pp.394-400
• /
• 1998

In this paper, we present a robust and fast method that enables real-time computing of axial motion component of different points of a scene from a stereo images sequence. The aim of our method is to establish axial motion maps by computing a range of disparity maps. We propose a solution in two steps. In the first step we estimate motion with a low level computing for an image point by a detection estimation-structure. In the second step, we use the neighbourhood information of the image point with morphology operation. The motion maps are established with a constant computation time without spatio-temporal matching.

• Journal of Biomedical Engineering Research
• /
• v.39 no.4
• /
• pp.153-160
• /
• 2018

3D ultrasound bladder scanners are getting popular in hospitals for the patients with bladder dysfunction. A current bladder scanner adopts a mechanical scan to acquire 3D images and requires two motors and complicated mechanical devices. In this paper, we propose a new ultrasound bladder scanner using hand-motion scan. Instead of two motors and mechanical devices, it has a motion sensor to record transducer positions during hand-motion scan. The experiments with a bladder phantom and volunteers showed similar measurement accuracy to a conventional 3D ultrasound bladder scanner. We expect that the proposed method will reduce the cost and size of the bladder scanner.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1731-1732
• /
• 2008

Recently, many researchers have developed various service robots, in which the position estimation and path following of mobile objects have been raised an important problem. We should know where a mobile robot so that there are many introduced localization and path following schemes. In this paper, we propose an efficient localization algorithm for the precise localization of a mobile robot with the glaser stream sensor. We use the glaser stream sensor for following a given path in indoor environments. Since the glaser stream sensor utilizes precise optical motion estimation technology, we can achieve high speed motion detection and high resolution. The experimental results show that the glaser stream sensor may be a good sensor for many indoor service robots.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.39 no.4
• /
• pp.418-428
• /
• 2002

In this paper, we propose a motion-adaptive de-interlacing method using motion compensated interpolation. In a conventional motion compensated method, a simple pre-filter such as line averaging is applied to interpolate missing lines before the motion estimation. However, this method causes interpolation error because of inaccurate motion estimation and compensation. In the proposed method, EBMF(Edge Based Median Filter) as a pre-filter is applied, and new matching method, which uses two same-parity fields and opposite-parity field as references, is proposed. For further improvement, motion correction filter is proposed to reduce the interpolation error caused by incorrect motion. Simulation results show that the proposed method provides better performance than existing methods.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.63.5-63
• /
• 2001

In this paper, moving objects tracking and dynamic characteristic analysis are studied. Kohonen´s self-organizing neural network models are used for moving objects tracking and time delay neural networks are used for dynamic characteristic analysis. Instead of objects brightness, neuron projections by Kohonen Networks are used. The motion of target objects can be analyzed by using the differential neuron image between the two projections. The differential neuron image which is made by two consecutive neuron projections is used for center detection and moving objects tracking. The two differential neuron images which are made by three consecutive neuron projections are used for the moving trajectory estimation.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.9
• /
• pp.96-105
• /
• 2015

This paper proposes a DSP optimization solution of rain detection and removal algorithm. We propose rain detection and removal algorithms considering camera motion, and also presents optimization results in algorithm level and DSP level. At algorithm level, this paper utilizes a block level binary pattern analysis, and reduces the operation time by using the fast motion estimation algorithm. Also, the algorithm is optimized at DSP level through inter memory optimization, EDMA, and software pipelining for real-time operation. Experiment results show that the proposed algorithm is superior to the other algorithms in terms of visual quality as well as processing speed.

• The Journal of the Acoustical Society of Korea
• /
• v.34 no.4
• /
• pp.321-327
• /
• 2015

In this paper, we propose an algorithm for achieving robust Visual Voice Activity Detection (VVAD) for enhanced speech recognition. In conventional VVAD algorithms, the motion of lip region is found by applying an optical flow or Chaos inspired measures for detecting visual speech frames. The optical flow-based VVAD is difficult to be adopted to driving scenarios due to its computational complexity. While invariant to illumination changes, Chaos theory based VVAD method is sensitive to motion translations caused by driver's head movements. The proposed Local Variance Histogram (LVH) is robust to the pixel intensity changes from both illumination change and translation change. Hence, for improved performance in environmental changes, we adopt the novel threshold estimation using total variance change. In the experimental results, the proposed VVAD algorithm achieves robustness in various driving situations.

• The Journal of the Korea Contents Association
• /
• v.16 no.6
• /
• pp.9-18
• /
• 2016

This paper proposes a multi-view Wyner-Ziv Video coding scheme based on spatio-temporal adaptive estimation. The proposed algorithm is designed to search for a better estimated block with joint bi-directional motion estimation by introducing weights between temporal and spatial directions, and by classifying effectively the region of interest blocks, which is based on the edge detection and the synthesis, and by selecting the reference estimation block from the effective motion vector analysis. The proposed algorithm exploits the information of a single frame viewpoint and adjacent frame viewpoints, simultaneously and then generates adaptively side information in a variety of closure, and reflection regions to have a better performance. Through several simulations with multi-view video sequences, it is shown that the proposed algorithm performs visual quality improvement as well as bit-rate reduction, compared to the conventional methods.

• International Journal of Control, Automation, and Systems
• /
• v.5 no.4
• /
• pp.410-418
• /
• 2007

For the purpose of fault detection of the primary control surface, real-time estimation of the longitudinal stability and control derivatives of the DURUMI-II using the flight data is considered in this paper. The DURUM-II, a research UAV developed by KARI, is designed to have split control surfaces for the redundancy and to guarantee safety during the fault mode flight test. For fault mode analysis, the right elevator was deliberately fixed to the specified deflection condition. This study also mentions how to implement the multi-step control input efficiently, and how to switch between the normal mode and the fault mode during the flight test. As a realtime parameter estimation technique, Fourier transform regression method was used and the estimated data was compared with the results of the analytical method and the other available method. The aerodynamic derivatives estimated from the normal mode flight data and the fault mode data are compared and the possibility to detect the elevator fault by monitoring the control derivative estimated in real time by the computer onboard was discussed.

• Proceedings of the IEEK Conference
• /
• 2000.11a
• /
• pp.505-508
• /
• 2000

The success of target reconstruction in SAR(Synthetic Aperture Radar) imaging system is greatly dependent on the coherent detection. Primary causes of incoherent detection are uncompensated target or sensor motion, random turbulence in propagation media, wrong path in radar platform, and etc. And these appear as multiplicative phase error to the echoed signal, which consequently, causes fatal degradations such as fading or dislocation of target image. In this paper, we present iterative phase error estimation scheme which uses echoed data in all temporal frequencies. We started with analyzing wave equation for one point target and extend to overall echoed data from the target scene - The two wave equations governing the SAR signal at two temporal frequencies of the radar signal are combined to derive a method to reconstruct the complex phase error function. Eventually, this operation attains phase error correction algorithm from the total received SAR signal. We verify the success of the proposed algorithm by applying it to the simulated spotlight-mode SAR data.