Introduction
Urgency
There is a set of the software products, allowing to compress graphic representations. But all of them compress images in the format set by the user, requesting at it necessary parametеrs of compression. The user himself makes the decision on how to compress the image or a number of images, frequently on ignorance choosing not the most suitable format or parametеrs.
The-decision of classical problems
One of serious problems of a machine drawing consists that the adequate criterion of an estimation of losses of quality of the image till now is not found. And it is lost constantly - at numbering, while translating in the limited palette of colours, while translating in other colorsystem for the press.
It is necessary to notice, that among existing methods is not present universal which would be effective for all kinds of raster images.
Is better losses of quality of images estimate our eyes. Excellent it is considered compression at which it is impossible to distinguish the initial and unpacked images approximately. Good - when to tell what of images was exposed to compression, it is possible only comparing two pictures being nearby. At the further increase in degree of compression by-effects, characteristic for the given algorithm, as a rule, become appreciable. In practice, even at excellent preservation of quality, in the image regular specific changes can be made. Therefore algorithms of compression with losses are not recommended to be used at compression of images which are going or to print further with high quality, or to process programs of recognition of images. Unpleasant effects with such images can arise even at simple scaling of the image.
Purpose and work problems
The purpose of master's work is developing of a computer subsystem of a choice optimum raster static images compression algorithm.
For achievement of the given purpose it is necessary to solve following problems:
· to consider existing algorithms of compression of images;
· to analyze character of raster static images, specificity of their use, and taking into account it to choose the most effective algorithms of compression;
· to define criterion of an optimality of algorithms taking into account specificity of a problem;
· to analyze possible methods of search of optimum algorithm and to choose most suitable of them;
· on the basis of the chosen method to create software product.
Application of following methods of research is supposed: the review of references and patent search in the given theme, including search in Internet; the engineering analysis of efficiency of application of existing algorithms and methods; comparison of actual results of work of various algorithms.
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