Correction of Axial and Lateral Chromatic Aberration With False Color Filtering

• Published in: IEEE transactions on image processing Vol. 22; no. 3; pp. 1186 - 1198
• Main Authors: Chang, Joonyoung, Kang, Hee, Kang, Moon Gi
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2013; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aberration; Algorithms; Applied sciences; CA correction; Cameras; chromatic aberration (CA); Color; Colorimetry - methods; Detection, estimation, filtering, equalization, prediction; digital still camera; Distortion; Exact sciences and technology; false color filtering; Filtering; Filtration; Image color analysis; Image edge detection; Image Enhancement - methods; Image Interpretation, Computer-Assisted - methods; Image processing; Information, signal and communications theory; Lenses; Photography - methods; Reproducibility of Results; Sensitivity and Specificity; Signal and communications theory; Signal processing; Signal Processing, Computer-Assisted; Signal, noise; Studies; Telecommunications and information theory; Transient analysis; transient improvement; Weight reduction; Performance evaluation; Filtering; Process improvement; Artefact; Chromatic aberration (CA); Algorithm; Blurred image; Digital photography; false color filtering; transient improvement; Image quality; digital still camera; Camera; Preprocessor; Color difference; Signal distortion; CA correction
• ISSN: 1057-7149; 1941-0042
• DOI: 10.1109/TIP.2012.2228489

In this paper, we propose a chromatic aberration (CA) correction algorithm based on a false color filtering technique. In general, CA produces color distortions called color fringes near the contrasting edges of captured images, and these distortions cause false color artifacts. In the proposed method, a false color filtering technique is used to filter out the false color components from the chroma-signals of the input image. The filtering process is performed with the adaptive weights obtained from both the gradient and color differences, and the weights are designed to reduce the various types of color fringes regardless of the colors of the artifacts. Moreover, as preprocessors of the filtering process, a transient improvement (TI) technique is applied to enhance the slow transitions of the red and blue channels that are blurred by the CA. The TI process improves the filtering performance by narrowing the false color regions before the filtering process when severe color fringes (typically purple fringes) occur widely. Last, the CA-corrected chroma-signal is combined with the TI chroma-signal to avoid incorrect color adjustment. The experimental results show that the proposed method substantially reduces the CA artifacts and provides natural-looking replacement colors, while it avoids incorrect color adjustment.