Exploration of feasible methods for detecting nighttime clouds using a digital camera without a NIR-cut filter

Nighttime clouds are detected using a camera without a NIR-cut filter by exploring the pixel value distribution in each red, green, and blue (RGB) color space from clear and 100% cloudy sky images. The removal of the NIR-cut filter enhances the pixel values of each color space due to the additional NIR signals. Cloud pixels can be separated from clear sky pixels by only using each color space and applying the appropriate threshold. Exploring different cloud detection methods is vital in our ongoing research activity collecting clear and cloudy sky images in other countries using this camera.