Joon Jae Lee

An efficient scattered data approximation using multilevel B-splines based on quasi-interpolants

In this paper, we propose an efficient approximation algorithm using multilevel B-splines based on quasi-interpolants. Multilevel technique uses a coarse to fine hierarchy to generate a sequence of bicubic B-spline functions whose sum approaches the desired interpolation function. To compute a set of control points, quasi-interpolants gives a procedure for deriving local spline approximation methods where a B-spline coefficient only depends on data points taken from the neighborhood of the support corresponding the B-spline. Experimental results show that the smooth surface reconstruction with high accuracy can be obtained from a selected set of scattered or dense irregular samples.

Keypad Inspection System of Cellular Phone

In this paper we describe a keypad inspection of cellular phones using image processing. Before keypad buttons are assembled, they occur problems such as surface chipping, color difference, and font errors under process. To solve these problems and to improve the quality of the products, automatic keypad inspection is required. This paper deals with development of inspection method so that objects are moved and rotated for matching to reference image, when objects are in random direction and location in images. And then, for inspecting defect of keypad button, all images of the same patterns of keypad buttons are sequentially matched by the proposed method.