تحسين المعلومات الطيفية للمستويات الرمادية في الصور الرقمية

Abstract

This research has demonstrated the most important techniques of spectral
information enhancement in digital images. It aims at achieving better display for the
contents of the image in order to have more appropriate results for specific
application. One of the most well known techniques of enhancement is the stretch of
contrast between image pixels, especially those which have close gray levels. This is
done by spreading the levels of brightness of the scene in order to cover all the levels
of gray (0-255) from black to white. The research has demonstrated four algorithms
for image enhancement of spectral information: the algorithm of linear enhancement,
logarithmic, exponential and histogram equalization. The research has dealt with
these techniques concentrating on: the input, the processing, the output and the
significance of applying these algorithms. The algorithms hade been applied on
tested images that are fed to the computer through the scanner or through digital
cameras. The comparison between the enhanced and tested images was proves that
the practical application of these algorithms is fruitful with showing the histograms
of the images before and after the enhancement.