Fractional-Order Integration Based Fusion Model for Piecewise Gamma Correction Along With Textural Improvement for Satellite Images

Abstract

Fractional-order integration (FOI) and its beauty of optimally ordered adaptive filtering for image quality enhancement are latently too valuable to be casually dismissed. With this motivation, a new Riemann-Liouville fractional-order calculus-based spatial-masking methodology is proposed in this paper in association with counterbalanced piecewise gamma correction (PGC). A generalized FOI-based mask is also suggested. This mask is negatively augmented with the original image for harvesting texture-based benefits. PGC is just employed through a constructive association of both kinds of reciprocally dual gamma values (gamma(1) = gamma and gamma(2) = 1/gamma, for all gamma > 1), which leads to optimally desired enhancement when applied in a weighted counter-correction manner. Efficiently improved and recently proposed opposition-based learning inspired sine-cosine algorithm is employed in this paper, along with a newly framed fitness function. This iftness function is devised in a novel manner by taking care of textural as well as non-textural details of the images. In this paper, especially for dark images, 130% increment is achieved over the input contrast along with the simultaneous 147% increment in the discrete entropy level and 22.8% increment in the sharpness content. Also, brightness and colorfulness are reported with 130% and 196.4% increased with respect to the input indices, respectively. In addition, the textural improvement is advocated in terms of desired comparative reduction of gray-level co-occurrence matrix-based metrics, namely, correlation, energy, and homogeneity, which are suppressed by 25.6%, 72.5%, and 21.8%, respectively. This performance evaluation underlines the excellence and robustness for imparting proper texture as well as edge preserved (or efficiently restored) image quality improvement.