A novel approach for enhancing very dark image sequences

Full Text
novelApproach.pdf embargoed access
Request a copy
When filling the form you are requesting a copy of the article, that is deposited in the institutional repository (DUGiDocs), at the autor or main autor of the article. It will be the same author who decides to give a copy of the document to the person who requests it, if it considers it appropriate. In any case, the UdG Library doesn’t take part in this process because it is not authorized to provide restricted articles.
We propose the methods, involving a denoiser and a tone mapper, that especially enhance very dark image sequences having an extremely small signal-to-noise ratio (SNR). The proposed denoiser and tone mapper, respectively, boosts the very small SNR and enlarges the extremely low dynamic range: they jointly form a conceptual framework to do the enhancement. We explicitly show that the conceptual framework adheres to a theoretical biological model of visual systems in nocturnal animals. The developed denoiser utilizes adaptive spatial-temporal filtering and effectively succeeds in reducing high noise and motion blur artifacts while preserving image details. The devised tone mapping method carries out different transformations for low and high intensity pixels by employing a single function which meanwhile takes into account the local contrast of each pixel, supporting a spatially and temporally consistent tone adjustment per frame. The conceptual framework and a customized post-process lead to a novel technique that is demonstrated to accomplish a satisfactory enhancement of very dark videos, and produce high quality restored image sequences - outperforming the recent state-of-the-art results. Finally, the proposed adaptive spatial-temporal filter and the post-processing procedure can be combined and adapted for normal-light image sequences to deal well with remarkably heavy noise ​
​Tots els drets reservats