Underwater Image Quality Optimization Using Color Correction and Contrast Enhancement

Underwater images often suffer from poor quality due to the challenging conditions of the underwater environment. Therefore, image enhancement techniques are crucial for improving color accuracy, increasing object visibility, and enhancing overall image quality. This study introduces an effective approach to improve underwater images, consisting of two primary steps: color correction and contrast enhancement. In the color correction step, a contrast-constrained adaptive histogram equalization (CLAHE) method is combined with a normalized gamma transform to improve the image quality. The key innovation of this method lies in integrating the normalized gamma correction into CLAHE to avoid contrast imbalance and reduce the over-brightness commonly caused by CLAHE. In the contrast enhancement step, a series of operations are applied to adjust pixel values, producing a gamma-normalized output. These two steps successfully restore the image's colors and maintain optimal contrast. Our evaluation results show that this method is highly effective in enhancing various underwater images.