Restoring images of ancient color postcards
This paper proposes an automatic system for the restoration of digital images of vintage colored postcards, employing the combined techniques of image equalization, background segmentation based on edge detection (using an extension of the standard difference of Gaussians filter), color enhancement, and noisy spots removal. Equalization and background segmentation are used to facilitate background spot removal. To enhance colors, the overall document degradation is regarded as an illumination problem, thereby allowing the use of color constancy algorithms. The methodology was applied to a set of postcards dating from the end of the nineteenth century, and satisfactory visual results were achieved.
edge detection difference of gaussians color constancy color image processing color restoration image restoration