Jung Gen Wu

Improved image compression using S-tree and shading approach

Distasi et al. (see ibid., vol.45, p.1095-1100, 1997), presented a storage-saving image compression method called the B-tree triangular coding (BTTC) method. Based on the modified S-tree data structure and the Gouraud shading method, this paper presents an improved image compression method railed the S-tree compression (STC) method. Experimental results illustrate that the bit rates and the image quality of the proposed STC method are quite competitive with the BTTC method, Due to the simple geometrical decomposition in the STC method, the ratio of the execution time or the proposed method over the BTTC method is less than 1/2.

Level-compressed Huffman decoding

Based on the breadth-first search manner and the level-compression technique, this article first presents a new array data structure to represent the classical Huffman (1952) tree. Then, the decoding algorithm is given. Both the memory and the decoding time required in the proposed method are less than those of previous methods. Some experimentations are carried out to demonstrate the advantages of the proposed method. In fact, the proposed algorithm can be applied to the canonical Huffman tree.

A New Binary Image Representation

Using bincodes to represent binary images is shown to be very simple and storage-saving. Given a set of bincodes, this paper presents two improved codes, namely, the logicodes and the restricted logicodes to represent binary images. We first transform the given bincodes into a set of logical expressions. Then a minimization technique is employed to reduce the storage space required for these logical expressions, thus obtaining the logicodes, on which set operations can be applied directly. Further, we put some restrictions into these logicodes to make each resulting logicode, called the restricted logicode, representing a connected black block. Given 20 different-type real images, experimental results show that our logicodes (restricted logicodes) present a saving of 29% to 44% (12% to 34%) with respect to bincodes. When compared to Sarkars method, except spending a little more space, our proposed codes do have three advantages: (1) it is easier to extract the related geometrical coordinates; (2) the bincodes can be used as direct input; i.e., they do compress the bincodes further; and (3) each restricted logicode represents a connected block block.

A model-based expert system for digital system design

An expert system that generates digital system design from high-level specifications is described. It is called MBESDSD, short for model-based expert system for automated digital systems. The syste...An expert system that generates digital system design from high-level specifications is described. It is called MBESDSD, short for model-based expert system for automated digital systems. The system is based on a three-phase model of digital system design. First, the high-level behavioral specifications are translated into a sequence of primitive behavioral operations. Next, these primitive operations are grouped to form intermediate-level behavioral functions. Finally, structural function modules are selected to implement these functions. The advantages of this model-based reasoning technique is that more design solutions are possible and the design is easier to optimize. The design of a popular peripheral device, the ART asynchronous receiver/transmitter, is used to demonstrate the proposed design process using MBESDSD.<<ETX>>

The Logical Representation of Bincode and its Applications in Manipulating Binary Images

Encoding digital binary images by using bincodes is very simple and storage-saving. Many efficient algorithms have been developed for manipulating images represented by bincodes. Among these algorithms, however, some special treatments on individual bits within bincodes are often needed. This strongly increases computational complexity. In this paper, we first transform the bincode into a new logical representation. Then, we apply some logical operations on these logical expressions to manipulate images efficiently. Finally, nine basic image operations are implemented in hardware which can be viewed as a special-purpose processor to speed up these operations in order to meet the real-time imaging demand. Experimental results are illustrated to demonstrate the good performance of our hardware implementation.

EFFICIENT SEARCH ALGORITHM ON COMPACT S-TREES

Abstract Based on the S-tree, the modified S-tree is a newly proposed spatial data structure for representing digital binary images, which can support fast search and query in pictorial database. In this paper, we first present a new spatial data structure called the compact S-tree to represent binary images, which uses less memory when compared to the modified S-tree. We then present a fast search algorithm on the compact S-tree. Further, the application to neighbor finding is also investigated. Experimental results show that the proposed search algorithm is faster than the previous known results on the S-tree and the modified S-tree.

A parallel algorithm for solving special tridiagonal systems on ring networks

The solution of special linear, circulant-tridiagonal systems is considered. In this paper, a fast parallel algorithm for solving the special tridiagonal systems, which includes the skew-symmetric and tridiagonal-Toeplitz systems, is presented. Employing the diagonally dominant property, our parallel solver does need only local communications between adjacent processors on a ring network. An error analysis is also given. On the nCUBE/2E multiprocessors, some experimental results demonstrate the good performance of our stable parallel solver.ZusammenfassungWir betrachten die Lösung einer Klasse von speziellen tridiagonalen Gleichungssystemen, die schiefsymmetrische und Töplitz-Systeme einschließt, und geben einen schnellen, parallelen, Algorithmus dafür an. Bei Vorliegen von Diagonal-Dominanz benötigt unser paralleler Solver nur Kommunikation zwischen benachbarten Prozessoren auf einem Ring-Netzwerk. Eine Fehleranalyse wird angegeben. Einige experimentelle Resultate, die auf einem nCUBE/2E Gerät gewonnen wurden, zeigen das gute Verhalten unseres stabilen, parallelen Solvers.

A Model-Based Expert System For Digital Systems Design

In this paper, we present a model-based expert system for automatic digital systems design. The goal of digital systems design is to generate a workable and efficient design from high level specifications. The formalization of the design process is a necessity for building an efficient automatic CAD system. Our approach combines model-based, heuristic best-first search, and meta-planning techniques from AI to facilitate the design process. The design process is decomposed into three subprocesses. First, the high-level behavioral specifications are translated into sequences of primitive behavioral operations. Next, primitive operations are grouped to form intermediate-level behavioral functions. Finally, structural function modules are selected to implement these functions. Using model-based reasoning on the primitive behavioral operations level extends the solution space considered in design and provides more opportunity for minimization. Heuristic best-first search and meta-planning tech-niques control the decision-making in the latter two subprocesses to optimize the final design. They also facilitate system maintenance by separating design strategy from design knowledge.

A simple improved full search for vector quantization based on Winograd's identity

Vector quantization (VQ) technique is a well known method in image compression. Employing Winograds (1968) identity, this article presents a simple improved method in order to cut the computation time in the full search method for VQ nearly 50%. Some experiments are carried out to confirm the theoretical analysis.

FAST IMPLEMENTATIONS FOR MIRRORING AND ROTATING BINCODE–BASED IMAGES

Abstract The spatial data structure known as bincode is a simple and storage–saving encoding scheme for representing binary images. In this paper, we first present eight efficient operations for mirroring and rotating bincode–based images. Among the operations, certain special operations on individual bits within bincodes are needed. Then we present a newly proposed logical representation for implementing the bitwise operations in the operations. Finally, we implement the bitwise operations in hardware to speed up the special manipulations.