A Novel Approach on Dehazing Volcanic Crater Lake Hazy Scene Videos Based on Color Attenuation Prior

Abstract

A crater lake of Mt. Kelud active volcano formed after the eruption on February, 2014. Real time surveillance has been conducted for 24 hours using a CCTV camera on the top of the summit. The primary purpose of this observation is monitoring the volcanic activity, such as degassing and discoloration of crater lake water. These phenomenons became the symptoms of the volcanic activity. The weather condition is continuously changes between clear, cloudy, and hazy. Obviously, camera vision is obscured or even blocked by haze. Another problem is that airlight source is hard to estimate because the lake color tends to be brighter in clear conditions. In this paper, a dehazing technique is proposed based on color attenuation prior and contrast enhancement. In contrast enhancement, the transmission map was enhanced using adaptive gamma correction. Our data were analyzed using referenceless fog density estimation (FADE). Our experimental results give the best result when it comes to fog density (by 1.60912 density) compared to previous algorithms.