Abstract:
Liquid Crystal Display (LCD) is among the significant inventions of the 21st century, for the
display of images. It requires a backlight in order to display different images or frames of
a video. The use of power is quite huge in the standard LCDs, as the backlight requires the
complete luminance for different input images. Usually it is desirable to reduce the power
consumptions of LCDs which results in reduced contrast and brightness. So, the contrast
and brightness of image during power saving mode is very important for visual perception
and interpretation of any image or a video sequence.
In this research, an efficient hybrid algorithm is proposed. The first step involves constrained
L0 gradient image decomposition technique to enhance the image. Then in the second
step, brightness compensation and contrast enhancement scheme is adapted. It utilizes
the layered difference representation framework as global contrast enhancement scheme.
Then an accurate auto white balance scheme is applied so that the white balance of the image
can be controlled. Then the gamma correction is applied on the output of the second
step in order to maintain the original image’s brightness. In the last step, outcome of white
balance scheme and gamma correction are added according to some prescribed weights. The
results show improved brightness compensated contrast enhanced images whenever there is
50 percent reduction in backlight intensity, to save power.
The proposed algorithm is compared with the conventional algorithms using three objective
quality metrics: absolute mean brightness error ,measure of enhancement and universal
image quality index. The results of proposed technique are better as compared to existing
technique. The proposed efficient hybrid technique for LCDs, can maintain the luminance of
the images whenever the reduction in intensity of backlight is 50 percent, thus saving power.
