FITTING OF TONAL CURVE AND BALANCING OF GRAY LEVELS IN CONTRAST EXPANSION AND PRELIMINARY IMAGING OF STRUCTURES IN THE ANALYSIS

Marek R. Ogiela

doi:10.7494/csci.2000.2.0.3580

Authors

Marek R. Ogiela AGH University of Science and Technology

DOI:

https://doi.org/10.7494/csci.2000.2.0.3580

Abstract

The article presents a group of transformations which medical pictures can be subjected to, in the aim of enhancing their contrast and better distinguishing and diagnosis of organs shown in this pictures. In this work the analysis was based on images acąuired by various techniąues, such as roentgenography (RTG), magnetic resonance (MRI), classic Computer tomography (CT) and ultrasonography (USG). Contrast expansion in these images was performed using the histogram mcthod of balancing of gray levels and the method based on the modification of tonal curve. Such transformations were necessary during preliminary processing of these images, especially to adjust their quality for next steps of the analysis in case of automatic medical diagnosis, and also to enable their visua! evaluation by specialists and diagnostic interpretation of images of or gans and their structural features. The studies show that the method based on the modification of tonal curve yields better results in case of images acąuired by roentgenography and magnetic re sonance imaging. On the other hand, histogram method is morę suitable for contrast expansion in CT and USG images.

Downloads

Download data is not yet available.

References

Ogiela M. R.: The Assessment o f the Possibilities o f Computer-BasedImage Proces singfor Pancreatic Duet Visualisation. Image Processing & Communications, 1995, Vol. 1, No. l,pp. 59-73

Ogiela M. R.: Computer Analysis o f ERCP Images with an Attempt at Diagnostics. Polish Journal of Medical Phisics and Engineering, Vol. 2, No. 3, pp. 21-Al, 1996

Ogiela M. R.: Languages ofshapefeature description and syntactic methodsfor re- cognition o f morphological changes o f organs in analysis o f selected X-ray images. SPIE’s International Symposium Medical Imaging 1998, San Diego CA, USA, 23-27 February 1998, SPIE Vol. 3338, pp. 1295-1305.

Pratt W. K.: Digital Image Processing. New York, Wiley & Sons 1991

Ritter G. X., Wilson J. N.: Computer Vision Algorithms in Image Algebra. CRC Press, Inc., BocaRaton, 1996

Weeks A. R.: Fundamentals of Electronic Image Processing. SPIE Press, Vol. PM32,1996