Problems in Applying Arithmetic Operations in Medical Imaging: X-ray Example

A lot of monadic, dyadic and aritmetic operations are performed in digital image manipulation. However, in practical implementation of such operations, a lot of obstacles were observed. These problems are more pointed in medical applications. The entire branch of computer-assistance in medicine is far more sensitive to the problems in image manipulation due to the information that might be lost or changed. In this paper, a few of the problems are discussed on the examples from medical practice. Why to performe arithmetic operations and what is the influence of application of aritmetic operations to the medical image are the questions to which we seek the answer. The authors illustrated these problems in the example of diagnostics of pulmonary diseases from X-ray image. Since some of the problems deals with human visual threshold, the experiment was performed and experimental results on human visual sensitivity are presented. The experiment is performed under 109 test subjects, mostly students from Split Collegue of Maritime Studies.