A spectral hazy image database

We introduce a new database to promote visibility enhancement techniques intended for spectral image dehazing. SHIA (Spectral Hazy Image database for Assessment) is composed of two real indoor scenes M1 and M2 of 10 levels of fog each and their corresponding haze-free (ground-truth) images, taken in the visible and the near infrared ranges every 10nm starting from 450 to 1000nm. Thus, the number of images that form SHIA is 1540 with a size of 1312 × 1082 pixels. The hazy images and the haze-free images are captured under the same illumination conditions. Three of the well-known dehazing image methods belonging to different categories were adjusted and applied on the spectral hazy images. This study confirms once again a strong dependency between dehazing methods and fog densities. It urges the design of spectral-based image dehazing able to handle simultaneously the accurate estimation of the parameters of the visibility degradation model and the limitation of artifacts and post-dehazing noise. The database can be downloaded freely at http://chic.u-bourgogne.fr.