Jun-Sik Kwon

An enhanced thinning algorithm using parallel processing

A thinning algorithm is a very important factor in recognizing the characters, figures and drawings. Until comparatively lately, various methods have been proposed for the thinning algorithm. We ascertain the point at issue of ZS, LW and WHF algorithms that are parallel thinning algorithms. The parallel thinning algorithm means that the first processing does not have to influence the second processing. the ZS algorithm has a problem that loses pixels in slanting lines and the LW algorithm does not have one pixel width in slanting lines. We propose an enhanced parallel thinning algorithm that connects the pixels to each other and preserves the end point.

Vehicle Tracking using Template Matching based on Feature Points

We propose a new vehicle tracking system which can detect and monitor vehicles as they break traffic lane rules. Our proposed tracking scheme is based on characteristics of both traffic scene and vehicle. These include: background information, local position, and the size of a moving vehicle. The initial size and position of the vehicle are obtained using a 4-directional contour tracking method. The object contour is made less sensitive to luminosity changes by incorporating a frame differencing operation. Each vehicle can be described with four feature points. The template region is estimated by means of a minimum distance approach with respect to center position. Our experimental results confirm that extraction of feature points from each frame of the scene improves the efficiency of vehicle tracking systems. Furthermore, adjustment of the vehicle region with matched points of template resolves the previous problem of occlusion

Design and implementation of a wearable AR annotation system using gaze interaction

In this work, we present an interactive optical see-through HMD (head-mounted device) which makes use of a users gaze information for the interaction in the AR (augmented reality) environment. In particular, we propose a method to employ a users half-blink information for more efficient interaction. As the interaction is achieved by using a users eye gaze and half-blink information, the proposed system can provide more efficient computing environment. In addition, the proposed system can be quite helpful to those who have difficulties in using conventional interaction methods which use hands or feet. The experimental results present the robustness and efficiency of the proposed system.

Two-dimensional object recognition using chamfer distance transform on morphological skeleton

In this paper, we propose a new method to represent the 2D shape and to recognize the object. In previous approaches, the boundary information is generally employed to recognize the 2D object. The points extracted from the polygonal approximation of the boundary are considered as the features and the point pattern matching is used. The methods, however, have the difficulty in the recognition of changeable objects. Thus we obtain the morphological skeleton and the distance transform and use them in the 2D object recognition. The matching method has the invariant features (rotation, translation, and scaling) and is a class of stochastic approach. And then the proposed method is employed effectively for the recognition of the changeful shaped object, e.g., tools like a wrench and a stripper or marks of the different shape and size.

Estimation of 3-D orientation of projective textures using morphological method

On the premise that the texture image is planar surface, we present a new morphological approach to obtain a surface orientation using the variation of texture image caused by projective distortions. Centroids of texels can be obtained from the farthest texel to the nearest texel sequentially by recursive erosions, so an entire texture image is segmented into several sub-regions. Using the major axes and the size of structuring elements in segmented regions, we can compute the vanishing point and obtain the 3-D surface orientation. In the experimental results, we have ascertained the proposed algorithm was more effective than the aggregation transform.<<ETX>>

Image-based relighting in dynamic scenes

Image-based lighting (IBL) is the process of illuminating scenes and objects with images of light from the real world. To generate a high quality synthesized image, consistency of geometry and illumination has to be taken into account. In general, lighting design for realistically rendering synthetic objects into a real-world scene, is labor intensive process and not always successful. Though many researches on IBL have been presented up to now, most of them assumed static situations that light sources and the objects were not moved. This paper presents a novel algorithm that integrates synthetic objects in the real photographs by using the global illumination model and HDR (High Dynamic Range) radiance map. We identify the camera positions and the light types, and then construct 3D illumination environment of the scene. The proposed method makes it possible to handle dynamic scenes and generate photo-realistic images.

Reconstruction of linearly parameterized models three vanishing points from a single image of perspective projection

A method using only three vanishing points to recover the dimensions of object and its pose from a single image of perspective projection with a camera of unknown focal length is presented. Our approach is to compute the dimensions of objects which are represented by the unit vector of objects from the image. The dimension vector v for the objects can be solved by the standard nonlinear optimization techniques with a multistart method which generates multiple starting points for the optimizer by sampling the parameter space uniformly. This method allows model-based vision to be computed the dimensions of object for a 3D model from matches to a single 2D image. Therefore, experimental results show the evaluated values of the object dimensions from a single image using three vanishing points. In addition, the actual dimensions of object from the image agree well with the calculated results.

Obtaining surface orientation of texture image using mathematical morphology

In this paper, we present a new morphological approach to obtain a surface orientation using the variation of texture image caused by projective distortions. The perspective effect and the foreshortening are considered as the projective distortions. Under the assumption that the surface of texture image is plane, we apply the mathematical morphology in order to compute the 3D surface orientation. Centroids of texels can be obtained from the farthest texel to the nearest texel sequentially by recursive erosions, so the entire texture image is segmented into several sub-regions. We may compute a major axis of each sub-region with centroids and an average slope with all major axes. Intersections between the line perpendicular to the average slope and the major axes are obtained. Using the relations between the intersections and the size of structuring elements in each sub-region, we can compute the vanishing point. The entire region is rearranged using the major axes of sub-regions and the lines converging to the vanishing point. We can obtain the surface orientation by using the vanishing point and the perpendicular line. We have demonstrated experimental results with the artificial image and the natural images. In the experimental results, we have ascertained the proposed algorithm was more effective than the algorithm using the aggregation transform with the texel edge.

Application algorithm of mathematical morphology for SMT

In this paper, we propose a new visual positioning and inspecting algorithm. The positioning algorithm is the process of computing the center position and the rotated angle of the surface mount device. The inspecting algorithm is capable of detecting the location of broken or bent leads. The morphological opening is applied to obtain a leadless image of the quad flat package or the small outline package, and the leadless image is able to be treated like an image of the square-shaped passive devices. The center position and the rotated orientation are found by four corner points which are obtained from the morphological skeleton subsets of the leadless image. After finding them, the hit and miss transform is utilized to extract the feature of the corner identification (ID). The ultimate orientation is determined correctly using results detected by hit structuring element and miss structuring element which satisfy the feature of the corner ID. The morphological inspection is executed extending over two steps, i.e., a rough inspection and a detailed inspection. The former is practiced before finding the center and the orientation, and the latter is performed after finding them.