Iki devyniolikto amžiaus devinto dešimtmečio pradžios kompiuterinė grafika buvo labai maža, specializuotas veiklos sfera. To priežastis buvo brangi techninė įranga ir mažas taikomųjų programų, kurios būtų ne brangios bei efektyvios, pasirinkimas. Tokių programų skaičius žymiai išaugo, kai pasirodė personaliniai kompiuteriai su vaizduokliais ir vartotojas galėjo tiesiogiai dirbti su grafiniais vaizdais. Nuo to laiko kompiuterinė grafika ir taškinių vaizdų apdorojimas labai stipriai patobulėjo. Tai tapo inžinerinių, informatikos, fizikos, medicinos bei biologijos mokslo šakų disciplinomis universitetuose. Viena iš sričių, kuri pažengė toliausiai šioje srityje yra kompiuterinis dizainas (CAD). Buvo pasiūlyta naudoti vektorinį duomenų formatą vietoje taškinių vaizdų, kadangi vektorinis formatas yra patogesnis ir tinkamesnis saugoti duomenims. Todėl atsirado būtinybė senus popierinius darbus, naudotus prieš pasirodant CAD sistemoms, paversti į vektorinį formatą. Pačioje pradžioje tai buvo atliekama rankiniu būdu, tačiau tobulinant taškinių vaizdų apdorojimo priemones buvo sukurti specializuoti įrankiai padedantys taškinius vaizdus versti į vektorinį formatą (vektorizuoti). Šių tezių tikslas yra sukurti bei patobulinti sistemą gebančią vektorizuoti taškinius vaizdus. Palyginti naudojamus algoritmus bei sistemos veikimą su panašiomis sistemomis. Šių tezių teorinėje dalyje yra detaliai aprašyti vektorizavimo procesą sudarantys veiksmai bei algoritmai. Projektinėje dalyje pateikti... [toliau žr. visą tekstą] / Until the early 1980`s, computer graphics was a small, specialized field, largely because the hardware was expensive and graphics-based application programs that were easy to use and cost effective-were few. Then personal computers with built-in raster graphics displays popularized the use of graphics for user – computer interaction and as they become more affordable, an explosion of easy-to-use and inexpensive graphics-based applications soon followed. Since then, computer graphics and image processing have experienced vigorous growth, having been subject to interdisciplinary study and research in such fields as engineering, computer science, physics, chemistry, biology and medicine. One of the areas that have benefited a great deal was computer aided design (CAD). Several non-raster based graphics formats – vector formats – were introduced as more convenient and appropriate means of storage for CAD systems. It became necessary for print work produced before the appearance of CAD systems to be reinstated in electronic form. In the early days this work had to be done manually. Later, with the development of image processing, specialized tools were devised to tackle the problem of vectorization, or raster-to-vector conversion. The aim of this thesis is to improve vectorization system, and to compare vectorization results with similar systems. The main steps of raster data vectorization is discussed in this document. In project part of this thesis you will find the main... [to full text]

The problem of raster images vectorization was analyzed and researched in this work. Existing vectorization systems are quite expensive, the results are inaccurate, and the manual vectorization of a large number of drafts is impossible. That‘s why our goal was to design and develop a new raster images vectorization system using our suggested automatic vectorization algorithm and the way to record results in a new universal vectorial file format. The work consists of these main parts: analysis, design, user documentation and experimental research. Conclusions of the analysis of this field are that the optimal solution of vectorization is the synthesis of automatic and manual vectorization. Users’ requirements were documented and raster image vectorization system designed. It was noticed that the result of vectorization depends on: vectorization algorithm; vectorization parameters; quality of raster image and user experience in this field. The core problems of vectorization are: symbol, intersection and corners recognition, lines‘ and their endings‘ types, filled areas. Vectorization results of our system and Corel TRACE were compared during the experimental research.