Enhancement of Faded Images Using Integrated Compensation Coefficients Based on Multi-Scale Gray World Algorithm

Abstract

Key Words : faded image enhancement, gray world algorithm, multi-scale process ABSTRACT Fading effect of old pictures and printings is shown up differently according to the ink property, temperature, humidity, illuminants, and so on. Faded image enhancement techniques based on illuminant estimation are proposed such as the gray world algorithm and white patch retinex methods. However, conventional simple operators are not suitable for enhancing faded images because partial fading effect is appeared differently. Thus, this paper presents a color enhancement algorithm based on integrating correction coefficients for faded images.First, the proposed method adopts local process by using multi-scale average mask. The coefficients for each multi-scale average mask are obtained to apply the gray world algorithm. Then, integrating the coefficients with weights is performed to calculate correction ratio for red and blue channels in the gray world assumption.Finally, the enhanced image is obtained by applying the integrated coefficients to the gray world algorithm. In the experimental results, the proposed method reproduces better colors for both wholly and partially faded images compared with the previous methods.

Implementation of Realistic Digital Contents in Virtual Space: Create and Display the Virtual Objects

“…And, the GWA(Gray World Assumption) algorithm is applied to achieve the color constancy between photos and the UV texture map [4]. Through these processes the realistic digital contents are created for the realistic representation in virtual space.…”