Fig. 2: Degradations of ancient Japanese manuscripts.

Representative examples of various types of degradation observed in a page of an ancient Japanese manuscript. Colored boxes indicate distinct categories of deterioration and their corresponding magnified regions on the right. Red solid boxes a, b, c denote stains, blue solid boxes d, e indicate faded text regions or loss character, and green solid boxes f highlight bleed-through areas where ink has penetrated from the reverse side. Each enlarged patch on the right corresponds to the same color-coded region on the left. These examples illustrate the complexity of mixed degradations-including discoloration, text fading, and bleed-through-that motivate the need for multi-class clustering and mask-guided restoration in the proposed framework. All images were derived from high-resolution scans of the Tsurezuregusa manuscript (National Institute of Japanese Literature, CODH dataset).