@Article{jqc.2021.020734,
AUTHOR = {Lord Amoah, Ampofo Twumasi Kwabena},
TITLE = {A Bi-Histogram Shifting Contrast Enhancement for Color Images},
JOURNAL = {Journal of Quantum Computing},
VOLUME = {3},
YEAR = {2021},
NUMBER = {2},
PAGES = {65--77},
URL = {http://www.techscience.com/jqc/v3n2/42998},
ISSN = {2579-0145},
ABSTRACT = {Recent contrast enhancement (CE) methods, with a few exceptions, 
predominantly focus on enhancing gray-scale images. This paper proposes a bihistogram shifting contrast enhancement for color images based on the RGB (red, 
green, and blue) color model. The proposed method selects the two highest bins 
and two lowest bins from the image histogram, performs an equalized number of 
bidirectional histogram shifting repetitions on each RGB channel while 
embedding secret data into marked images. The proposed method simultaneously 
performs both right histogram shifting (RHS) and left histogram shifting (LHS) in 
each histogram shifting repetition to embed and split the highest bins while 
combining the lowest bins with their neighbors to achieve histogram equalization 
(HE). The least maximum number of histograms shifting repetitions among the 
three RGB channels is used as the default number of histograms shifting 
repetitions performed to enhance original images. Compared to an existing 
contrast enhancement method for color images and evaluated with PSNR, SSIM, 
RCE, and RMBE quality assessment metrics, the experimental results show that 
the proposed method's enhanced images are visually and qualitatively superior 
with a more evenly distributed histogram. The proposed method achieves higher 
embedding capacities and embedding rates in all images, with an average increase 
in embedding capacity of 52.1%.},
DOI = {10.32604/jqc.2021.020734}
}