A Review on Underwater Image Enhancement

While capturing underwater image there are lot of imposed due to low light, light variation, poor visibility. Photography is about light, but since water has an a lot more prominent density than air — around 800 times more noteworthy not all wavelengths of light travel similarly well inside it. This implies as we go down into deep water, we lose the shades of the range one by one. This is the reason submerged photographs lose all the red and orange hues even at a genuinely shallow profundity and appear to be increasingly more blue as we go deep in water, henceforth captured image need enhancement. It’s a vital research area, in this paper we will review different techniques of underwater image enhancement.

Updated pulsation period relations of γ Dor-type stars in eclipsing binaries: the case of KIC 2557430

ABSTRACT We employ optical spectroscopy and Kepler photometry to derive the physical properties and pulsational characteristics of the detached system KIC 2557430. We find that the system is formed by F-type components. Combining results from the analysis of spectroscopic data and Kepler photometry, we calculate masses and radii of the primary and the secondary components as M1 = 1.69 ± 0.03 M⊙, M2 = 1.35 ± 0.02 M⊙ and R1 = 1.88 ± 0.02 R⊙, R2 = 1.23 ± 0.03 R⊙, respectively. Position of the primary component in the HR diagram is in the region of γ Doradus-type pulsators and the residuals from light curve modelling exhibit additional light variation with a dominant period of ∼0.5 d−1. These are clear evidence of the γ Doradus-type pulsations on the primary component. Focusing on the γ Dor primaries, with their currently known numbers in eclipsing binaries to compare against, we probe the role binary stars might play, to understand the nature of γ Dor-type pulsations.