engleski

Creating a synthetic image for evaluation of vignetting modeling and estimation

Vignetting is an effect caused by camera settings or lens limitations. It is also known as the "light fall-of" where the intensity of light decreases from the middle to the edges. Vignetting has become popular in various scientific papers where attempts are made to remove vignetting by various methods. The idea of this article would be to design a synthetic image of the vignetting effect that would mimic the starry night sky. It would be made by adding random white pixels to a previously set positive constant value modeling the sky glow, also adding Gaussian or Poison noise after applying vignetting effect itself with an arbitrarily chosen center point. Parameters of the vignetting module can be set manually defining the ground truth module, thus modeling the actual multispectral lens response functions. Such an image could be used as ground truth for vignetting modeling and estimation functions to evaluate different methods and their accuracy as a function of signal to noise (SNR) ratio and noise type. The image is tested on two vignetting correction functions, both functions show great results, only the first has larger residual gain variations, especially toward the frame corners.

vignetting correction ; starry night sky ; radial-gradient method ; synthetic image

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