New approach in color distortion reduction in underwater coral reef color image enhancement based on estimation absorption using exponential equation

Indonesia’s coral reef shares 18% part of the world’s coral reef. It is estimated that Indonesia’s coral reef comprises of 51,000 km². It is estimated that 7% of coral reef is in very good condition, 33% good, 45% is damaged, and 15% poor. The color of coral reef indicates its health. One difficulty to identify the original color of coral reef is that the color changes when it is taken out of water. Color distortion of an underwater image is caused by light spread and color change. Color spread occurs because some light beam is reflected and refracted by underwater environment, whereas underwater object color change is caused by different light wave when spreading in the water. This research proposes an exponential approach to enhance the appearance of coral reef in underwater image. This approach restores the color constancy of red, green, and blue. The result is measured by using Peak Signal to Noise Ratio, and it gives PSNR value of 20.58. We concluded that exponential approach can enhance underwater coral reef color well.