The X Window System is an industry-standard software system which facilitates programmers to develop portable graphical user interfaces. This thesis describes an image processing tool developed under the X Window System. A multiwindow image display software with image editing and improvement functions is developed. The software has four modules: environment generation, image creation, image editing and image improvement. The environment generation module creates working windows, scrollbars, dialogbox and pulldown menu buttons, and tracks mouse cursor positions. The working windows are three adjacent windows allowing display of three different images simultaneously. The dialogbox provides an interface between the user and the program, such as input new image and parameters. The pulldown menus offer various selections of image processing functions. A pair of scrollbars are also added to allow users to move the magnified image up, down, left and right so that the full picture can be viewed. The image creation module can build colormap, load image data file, convert pixel values to screen color values, create image, and display image on the screen of a workstation. The program can read either sun.rasterfile format or a plain data file. If a plain data file is detected, the software can transform it to sun.rasterfile by adding an appropriate header and a colormap. There are two kinds file saving features: screen capture and store. The screen capture allows the user to save that part of image displayed on the screen. The store function saves the entire image which may be either the screen size or bigger size image (e.g. merged or zoomed image). The image editing module is equipped with the functions for zooming (in or out) , merging, rotating and restoring images. The merge function constructs a new image based on the user selected or input image from the dialogbox. The rotation center of an image can be any point selected by user's clicking mouse button, and the rotation angle is supplied by user in the dialogbox. The image improvement module consists of some image point transformation and image enhancement functions. This software package is easier to use than existing tools for image processing. It has been used in the image processing projects and related educational purposes. The software provides a framework and can be easily extended to other potential applications.

Ces dernières années le déploiement de réseaux sans fil a changé le paysage des réseaux informatiques. Grâce à l'évolution de la technologie informatique un utilisateur peut étendre son environnement de travail habituel en bénéficiant de la connectivité réseau accrue. La gestion souple de la mobilité lui permet d'accéder à différents environnements de collaboration. Cette thèse considère le problème de partage de l'affichage d'applications dans les conditions de la diversification des contextes de collaboration. Étant donné le déploiement du système de fenêtrage X et du système d'affichage à distance VNC, nous les avons choisi comme base pour notre travail. D'une part, nous avons conçu un système de partage d'applications X qui gagne en flexibilité par son interface du contrôle d'évènements d'entrée. Le système repose sur un multiplexeur de flots X conçu comme un service actif qui peut être chargé dynamiquement sur une plate-forme générique. D'autre part, nous avons transformé le système VNC en un système coopératif flexible. Le nouveau système est construit autour d'un proxy dynamiquement contrôlé à distance. Le proxy peut être programmé pour gérer différentes sessions de collaboration. Chaque session de collaboration peut utiliser des flots de données de VNC multiples. L'ouverture du système vers des politiques de contrôle d'évènements entrée permet l'adaptation au contexte de coopération. Finalement nous présentons des nouvelles perspectives concernant les possibilités de collaboration assistée par la technologie informatique dans un réseau informatique quelconque.

Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 80-84).

X windows is a graphic display management system. It is designed to work on a variety of machines and display adapters, however it is not designed for terminals with local graphics capabilities. X windows can be made to work on this type of terminal, although in a slower and restricted form. The problem with designing a variation of X for these terminals is the translation from X requests to native graphics commands, and the mapping of terminal input into X events. These implementation issues are discussed and example code is provided. / Department of Computer Science

The purpose of the X-Form package is for use in the classroom as an instructional aid for teaching the algorithms and data used to represent, transform, and display objects in three-dimensional space. The program provides various areas containing graphic and textual representations of the data structures used in the creation and transformation of a three-dimensional object. Another area, containing the menu items, serves as an interface to the available demonstration items. These items include various object and viewing parameters which can be input by the user. The user then sees the result of the entered data, including animated graphics and changes in data structures. The graphic areas show the object at various stages of development, so that the user can understand the progression of the required manipulations. The textual representations are also designed to assist the user in understanding how useful information is derived from entered data. Through testing and statistical analysis, XForm has proven to be an effective tool for instruction of three-dimensional graphics. / Department of Computer Science

Thesis (M.Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 80-84) Also available in print.

A study was performed to develop an interactive plane frame analysis program. The program was designed to run on Unix-based workstations and to be independent of the hardware platform. This was achieved by selecting the XWindow system as the underlying graphical user-interface. An event-driven, window-based program was developed using the XWindow Toolkit. The entire program was written in the C programming language. The program consists of two parts: a preprocessor and a processor. The preprocessor employs pull-down menus and pop-up dialog boxes and provides a convenient way of creating and modifying structural models. The processor performs linear elastic analysis of plane frame structures based on the matrix displacement method. The processor computes joint displacements, support reactions and local member-end forces of the structure. It also handles internal hinges, joint loads, member loads, prescribed displacements, multiple load cases and load combinations. Other features include automatic mesh generation for orthogonal frames, automatic computation of self-weight and specification of output options. To verify the accuracy of the program, analysis results from the program were compared with results obtained from a commercial structural analysis program. A comparison of joint displacements, support reactions and member-end forces indicate that the difference in the values obtained from the two programs is less than two percent and that the program provides accurate analysis results. / Master of Science

This thesis describes the development of a graphical CAD tool for VHDL model development. The tool was developed for the X Windows environment. The graphical representation used is the process model graph [1,4]. The process model graph is input interactively and the tool generates the corresponding VHDL code. The design style is restricted to behavioral models. A new scheme was formulated for the development and use of reusable code in the form of primitives. A default set of primitives as presented in [5] was also developed. The tool can also attach to any VHDL analyzer available on the system and analyze the developed code. This tool is designed for use by system modelers and should simplify the process of model development, thus improving productivity. / Master of Science

In graph theory graphs are mathematical objects that can be used to model networks, data structures, process scheduling, computations and a variety of other systems where the relations between the objects in the system play a dominant role.We will now consider graphs as mathematically self-contained units with rich structure and comprehensive theory; as models for many phenomena, particularly those arising in computer systems; and as structures which can be processed by a variety of sophisticated and interesting algorithms.For graph theory presentation, we need a very good graphical user interface(GUI) to approach the goal. X Window system is ideally suited for such a purpose. This package program is based on X Window system environment. With this package, we can manipulate graphs by special functions which can put nodes, put edges, delete nodes, delete edges, change the whole graph size, move graph location, and modify edge weights. / Department of Computer Science

Die Arbeit präsentiert ein Multimedia-Framework für Linux, das im Unterschied zu früheren Arbeiten auf den Ideen "retained-mode processing" und "lazy evaluation" basiert: Statt Transformationen unmittelbar auszuführen, wird eine abstrakte Repräsentation aller Medienelemente aufgebaut. "renderer"-Treiber fungieren als Übersetzer, die diese Darstellung zur Laufzeit in konkrete Operationen umsetzen, wobei das Datenmodell zahlreiche Optimierungen zur Reduktion der Anzahl der Schritte oder der Minimierung von Kommunikation erlaubt. Dies erlaubt ein stark vereinfachtes Programmiermodell bei gleichzeitiger Effizienzsteigerung. "renderer"-Treiber können zur Ausführung von Transformationen den lokalen Prozessor verwenden, oder können die Operationen delegieren. In der Arbeit wird eine Erweiterung des X Window Systems um Mechanismen zur Medienverarbeitung vorgestellt, sowie ein "renderer"-Treiber, der diese zur Delegation der Verarbeitung nutzt.