A new PDE-based approach for singularity-preserving regularization: application to degraded characters restoration

Fadoua Drira, Frank LeBourgeois, Hubert Emptoz
2011 International Journal on Document Analysis and Recognition  
The massive digitization of heritage documents have raised new prospects for Research like degraded document image restoration. Degradations harm the legibility of the digitized documents and limit their processings. As a solution, we propose to tackle the problem of degraded text characters with PDE (Partial Differential Equation)-based approaches. Existing PDE-approaches do not preserve singularities and edge continuities while smoothing. Hence, we propose a new anisotropic diffusion by
more » ... new constraints to the Weickert coherence enhancing diffusion filter in order to control the diffusion process and to eliminate the inherent corner rounding. A qualitative improvement in the singularity preservation is thus achieved. Experiments conducted on degraded document images illustrate the effectiveness of the proposed method compared to another anisotropic diffusion approaches. We illustrate the performance with the study of the optical recognition accuracy rates.
doi:10.1007/s10032-011-0165-5 fatcat:lhlnpmi3cbfuvfluq3wiwqs34q