Blind Correction of Lateral Chromatic Aberration in Raw Bayer Data

Abstract

Chromatic aberration is an error that occurs in color images due to the fact that camera lenses refract the light of different wavelengths in different angles. The common approach today to correct the error is to use a lookup table for each camera-lens combination, e.g., as in Adobe PhotoShop Lightroom or DxO Optics Pro. In this paper, we propose a method that corrects the chromatic aberration error without any priot knowledge of the camera-lens combination, and does the correction already on the bayer data, i.e., before the Raw image data is interpolated to an RGB image. We evaluate our method in comparison to DxO Optics Pro, a state-of-the-art tool based on lookup tables, using 25 test images and the variance of the color differences (VCD) metric. The results show that our blind method has a similar error correction performance as DxO Optics Pro, but without prior knowledge of the camera-lens setup.

Surround-View Fisheye Optics in Computer Vision and Simulation: Survey and Challenges

“…Chromatic aberration is typically compensated for either through achromatic doublets in the optics (such as the optical doublet seen for the fisheye lens design in Figure 2) or in the Image Signal Processing (ISP) stage before demosaicing of a camera system [40], [41]. Demosaicing is the stage at which a Bayer RAW signal (having one color per pixel) is converted into the standard RGB format.…”

“…Lateral chromatic aberration is usually corrected using Look-Up Tables calculated for a given lens type as a post-processing step, but this is often not feasible. Recent work has examined blind methods for correcting lateral chromatic aberration [41]. It should be noted that the post-processing to compensate for chromatic aberration does not fix the problem.…”