Reconeixement robust de text manuscrit en situacions d'escasses anotacions: desenredament, adaptació i generació

• Autores: Lei Kang
• Directores de la Tesis: Mauricio Villegas Santamaría (dir. tes.), Alicia Fornés Bisquerra (codir. tes.), Marçal Rusiñol (codir. tes.)
• Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2020
• Idioma: español
• Tribunal Calificador de la Tesis: Prof. Dr.-Ing. Gernot A. Fink (presid.), Oriol Ramos Terrades (secret.), Verónica Romero Gómez (voc.)
• Programa de doctorado: Programa de Doctorado en Informática por la Universidad Autónoma de Barcelona
• Materias:
  • Ciencias tecnológicas
    • Tecnología de los ordenadores
      • Sistemas de reconocimiento de caracteres
• Enlaces
  • Tesis en acceso abierto en: TDX
• Resumen

  • Handwritten documents are not only preserved in historical archives but also widely used in administrative documents such as cheques and claims. With the rise of the deep learning era, many state-of-the-art approaches have achieved good performance on specific datasets for Handwritten Text Recognition (HTR). However, it is still challenging to solve real use cases because of the varied handwriting styles across different writers and the limited labeled data. Thus, both exploring a more robust handwriting recognition architectures and proposing methods to diminish the gap between the source and target data in an unsupervised way are demanded.

    In this thesis, firstly, we explore novel architectures for HTR, from Sequence-to-Sequence (Seq2Seq) method with attention mechanism to non-recurrent Transformer-based method. Secondly, we focus on diminishing the performance gap between source and target data in an unsupervised way. Finally, we propose a group of generative methods for handwritten text images, which could be utilized to increase the training set to obtain a more robust recognizer. In addition, by simply modifying the generative method and joining it with a recognizer, we end up with an effective disentanglement method to distill textual content from handwriting styles so as to achieve a generalized recognition performance.

    We outperform state-of-the-art HTR performances in the experimental results among different scientific and industrial datasets, which prove the effectiveness of the proposed methods. To the best of our knowledge, the non-recurrent recognizer and the disentanglement method are the first contributions in the handwriting recognition field. Furthermore, we have outlined the potential research lines, which would be interesting to explore in the future.