Edge-based vignetting factor estimation and correction comparative analysis

ABSTRACT

An edge-based (EB) iterative method for estimating the vignetting factor f from a vignette image is devised which assumes a radial brightness falloff associated with the existing vignetting effect. The method exploits the maximum value for an F valued image that is characterized by 8-bit integers {0,1,2, … ,255} away from the image centre. Additionally, the vignette factor f estimation is performed using the radial gradient method on a series of images with explicitly simulated and unknown source vignetting. Both techniques are implemented and compared such that the estimated vignette factor f and the vignette corrected images are assessed to determine deviation in the respective methods as well as their accuracy in controlled experiments.

KEYWORDS:

• f factor
• edge-based
• iterative
• radial
• geometry
• radial gradient
• vignette

Disclosure statement

No potential conflict of interest was reported by the author.

Notes on contributor

Travis Ramsay is pursuing his Ph.D. in Mechanical Engineering at Iowa State University (U.S.A.). Ramsay’s research focuses on coupled processes in computational mechanics. His previously obtained degrees include an Honors Bachelor of Science in Earth Science with a focus in Geomatics from York University (Canada) and a Master’s in Geology and Physics with a focus in Geodynamics from the University of Toronto (Canada).