This paper proposed an integration de-noising method based on self-adaptive manifold filtering and text contour for ancient Chinese calligraphy tablet image. It consists of two main operations in sequence: image smoothing with a non-local means (NL-means) based self-adaptive manifold filter and isolated blocks removal based on text contour. Experiments demonstrate that the proposed method is superior to several recent published stele image de-noising techniques in terms of preserving the character structures.
The Euler number of a binary image is an important topological property for pattern recognition, image analysis, and computer vision. In the proposed algorithm, only three comparisons need to be completed for processing a bit-quad in the given image. Moreover, the proposed algorithm processes three rows simultaneously in the scanning which will reduce the number of checked pixels from 4 to 1.5 for processing each bit-quad, which will lead to an efficient processing. Experimental results demonstrated that the performance of the proposed algorithm significantly overpasses conventional Euler number computing algorithms.