Chang-Ho Han

The Study of Improving the Accuracy in the 3D Data Acquisition of Motion Capture System

We introduced the motion capture system using two CCD cameras recently, but could not show any better accuracy than a system using PSD camera. In this paper, we propose two kinds of method to improve the accuracy of the 3D acquisition of the motion capture system using CCD cameras. The applied methods are a distortion removal and z-axis adjustment. We show the result how much the accuracy on the 3D acquisition system improved through comparing with the previous system.

Recognition of Fighting Motion using a 3D-Chain Code and HMM

In this paper, a new method to recognize various motions of fighting with an aid of HMM is proposed. There are four kinds of fighting motion such as hook, jab, uppercut, and straight as the fighting motion. The motion graph is generalized to define each motion in motion data and the new 3D-chain code is used to convert motion data to motion graphs. The recognition experiment has been performed with HMM algorithm on motion graphs. The motion data is captured by a motion capture system developed in this study and by five actors. Experimental results are given with relatively high recognition rate of at least 85%.

A study on enhanced algorithms for detecting defects of glasses

In this paper, we proposed image processing algorithms and developed the vision system for measuring blisters of flat glasses. The images captured by changing focus of camera because the depth of field of CCD camera is smaller than the depth of glasses and classified two types in blister as circle and ellipse types by the proposed criteria of measurement. We applied different methods to each type to improve the accuracy. In the pre-processing, it obtained binarized images to find blister. The information such as area, boundary, length, and position of blister has extracted from the binarized images by using chain code algorithm. For an illumination, the bright field illumination as back-light was applied. We tested the automatic measurement system, which we developed by using vision system, It successes 100% for detecting the blister at all glasses, and the error accuracy of information is about +/-10%.

Implementation of a 3D Recognition applying Depth map and HMM

Recently, we used to recognize for human motions with some recognition algorithms. examples, HMM, DTW, PCA etc. In many human motions, we concentrated our research on recognizing fighting motions. In previous work, to obtain the fighting motion data, we used motion capture system which is developed with some active markers and infrared rays cameras and 3 dimension information converting algorithms by the stereo matching method. In this paper, we describe that the different method to acquiring 3 dimension fighting motion data and a HMM algorithm to recognize the data. One of the obtaining 3d data we used is depth map algorithm which is calculated by a stereo method. We test the 3d acquiring and the motion recognition system, and show the results of accuracy and performance results.

Comparing two methods for acquiring 3D data of motion capture system by using PSD camera and CCD camera

This paper presents a monocular PSD-based motion capture system and CCD camera based system. The first system includes a PSD (Position Sensitive Detector) and active infrared (IR) LED markers that are placed on the object to be tracked. The PSD sensor is placed in the focal plane of a wide-angle lens. The microcontroller calculates the 3D position of the markers using only the measured intensity and the 2D position on the PSD. The second system includes two CCD camera and LED markers that are in hand and draw any motion trace. From the experimental results we see that the two kinds of methods for acquiring 3d data will be compare in accuracy, speed, process, methods, experimental circumstance.

An Implementation of OPC Client for Display Inspection System

OPC is the preferred communication standard for sharing process control data at all levels of the enterprise and becomes the global standard, sends/receives the data with PLC programs of inspection system via network, and manages various data using OPC server. In this paper, we introduce the developed OPC client system for FPD inspection system with OPC server. To control inspection system through OPC server, we have developed libraries which consist of stage driver, switch driver, microscope driver, image processing, alignment, and task management modules. Also we have developed the test program to verify all functions precisely. We describe the mechanism of inspection system, OPC connection method, and programs.

A 3D coordinate estimation by using reformed two IR LED markers and PSD camera

We introduced a low-cost and compact motion capture system which enables to play motion games in Play Station 2[1]. The Single-PSD motion capture system that used the intensity light of a marker has a weak measurement at an intensity variation. It is so difficult to make markers having omni-direction equal intensity in Single-PSD. In this paper, we propose a new method that solves aforementioned problems. It can measure 3D coordination with the relation of the optical characteristics if the intensity of a pair of markers is same at forward direction. We made a system based on this proposed method and experimented for performance capability. As a result, we were able to make the motion capture system to the robust system for bad factors, such as variation intensity of markers, external light. The system is stable to obtain 3d positions and an adaptable motion games. The improved system is expected to be useful in animation, movies and games.