Video Enhancement

Title: Exposure vs Contrast Enhancement in low light 4K videos

Abstract:

The terms ``exposure enhancement'' and ``contrast enhancement'' are usually used interchangeably for image enhancement in low light acquisitions. This paper argues that the two processes are anything but alike. While exposure can be inferred from low frequency or background of an image, contrast by definition refers to the ratio of the foreground with the background. We break down the lambertian illumination model in a multiresolution framework and show how foreground and background at different levels contribute to contrast and exposure enhancement. Following this, a fast multiresolution low light enhancement scheme is proposed that achieves a frame rate of 19.62 frames per second (fps) on recorded 4K video sequences without employing any graphical processing unit (GPU). Experiments reveal that the proposed scheme is not only fast, it also achieves state of the art performance in terms of subjective and objective assessment.

Github: https://github.com/sohaibali01/low-light-video-enhancement

Top Row: Original 4K frames from an UHD youtube video available here, Bottom Row: Proposed Enhancement available here

Top Row: Original 4K frames from an UHD youtube video available here, Bottom Row: Proposed Enhancement

Frame Rate on different HD resolutions

Ali, Roha, et al. "Exposure versus contrast enhancement in low-light 4k videos." Signal, Image and Video Processing 14.8 (2020): 1671-1678. (Input UHD video) (Output UHD video)