Ren-Jean Liou

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Image compression is an essential task for image storage and transmission. This paper presents a compression scheme for digital still images using Kohonenpsilas self-organizing map (SOM) algorithm with sub-band discrete cosine transform (DCT) features as inputs. Quadtree decomposition was applied first as preprocessing. It is an efficient way to segment(More)
Image thresholding is an important technique for image processing and pattern recognition. In this paper, a new multilevel image thresholding algorithm based on the technology of the honey bee mating optimization (HBMO) is proposed. Three different methods such as the particle swarm optimization (PSO), the hybrid cooperative-comprehensive learning based PSO(More)
In this paper, the honey bee mating optimization (HBMO) algorithm is used to improve the detection of the concave region connected with the control points of active contour. In the traditional active contour model (ACM) method, the updating of control point is based on its local energy within a small searching window. As a result, it always results in the(More)
Ultrasound has many important applications in nondestructive evaluation. Since ultrasonic signals can penetrate many materials, they are widely used for detection of flaws. However, the use of ultrasound is limited by interference, such as geometric interface, coarse grain, mode conversion and ringing. Hence it is practically difficult to perform evaluation(More)
The application of ultrasonic guided wave methods to both nondestructive evaluation (NDE) and structural health monitoring (SHM) is becoming more prevalent as techniques to handle their multi-modal and dispersive nature are developed. There are several applications where it would be not only convenient but perhaps essential to interpolate arrays of measured(More)
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