MAGE CONTRAST ENHANCEMENT USING HISTOGRAM EQUALIZATION

Abstract

Now a days everyone is facing the problem of low contrast photographs due to lightning condition and imaging system
and power consumption problem in various multimedia devices. To overcome this drawback a contrast enhancement as well as power
saving algorithm for emissive display is proposed in this paper. The conventional histogram equalization (HE) algorithm has s everal
drawbacks. First, when a histogram bin has a very large value, the transformation function gets an extreme slope. This can cause
contrast overstretching, mood alteration, or contour artifacts in the output image. Second, particularly for dark images, HE
transforms very low intensities to brighter intensities, which may boost noise components as well, degrading the resulting image
quality. Third, the level of contrast enhancement cannot be controlled since the conventional HE is a fully automatic algorithm without
any parameter. To overcome this drawback here we develop a log based histogram modification (LHM) technique, which reduce the
contrast overstretching of the conventional H.E technique. Then we design the contrast enhancement power saving algorithm for
emissive display and added it into the LHM to achieve the optimal tradeoff between contrast enhancement and power saving. The
proposed algorithm can reduce the power consumption significantly while improving the image contrast and perceptual quality.