Color saturation contrast enhancement technology for digital images

Abstract

Technological issues of latent graphic information disclosure through the use of  images' contrast enhancement are considered assuming the later visual analysis. Methods and tools to control the color saturation contrast are revised from the information point of view. When the analytical representation of control system is pointed to, – the description of color saturation conversion is detailed. When the graphic representation of control system is pointed to, – the description of method to control color saturation contrast is done. When the technological representation of control system is pointed to, – the description of algorithm to control color saturation contrast is revealed. While testing the established virtual-optic contrast-enhancing instrumentation, two concepts of contrast transform brake and accumulation of pixels (whose saturation conversion finishes with the beginning of brake action) are entered into consideration. The role of brake and accumulation in the image contrast formation is shown – edge effects are discussed. For various initial images program operation is illustrated within two more color saturation control modes - reversed and mixed ones. Both are complementary to <Saturation> instrument, used in modern software. The case is illustrated, when contrast-enhancement ratio becomes negative. On the example of only one total contrast component – color saturation contrast – the concept is investigated and two typical contrast analysis tasks are defined. Acquisition of the required graphic information is demonstrated at the solution of each task. As a result, the creation of new information technology is being announced. It differs from the existing one by extra efficiency – we mean expansion of initial images nomenclature – caused by <Saturation> supplement with two new informative processing modes. It differs also by elimination of the possibility to acquire artifacts caused by errors arising from brightness shift and from hue non-uniformity of saturation contrast transform, anyway inherent in all the modern software. Certain recommendations concerning images' contrast analysis application in the sphere of expert activities are outlined.