PLEASANT: Planetary Science Image Enhancement Technique Using PCA Matched Enhanced Colour Space Transformation and Adaptive Gamma Correction

Planetary science images are leveraged to advance our knowledge of the planets and other celestial bodies in the solar system. However, these images are captured in low illumination conditions and have limited usability for planetary science applications. There exist numerous state-of-the-art image enhancement techniques, but they do not provide optimal enhanced output for planetary remote sensing image interpretation and morphological feature analysis. The article introduces a novel planetary image enhancement method termed PLEASANT. In the proposed method, the first principal component of the input colour corrected planetary image is a histogram matched with the intensity channel enhanced by Contrast Limited Adaptive Histogram Equalization in the Hue Saturation Intensity colour space. Finally, adaptive gamma correction is applied to the transformed image for improving its overall brightness and contrast information. The proposed method PLEASANT is evaluated on planetary images acquired by the Indian Mars Colour Camera which is a payload onboard the Mars Orbiter Mission spacecraft. It is found that compared to other eminent image enhancement techniques, PLEASANT gives superior visual and quantitative image quality assessment results.