Deep Convolutional Recurrent Network for Segmentation-Free Offline Handwritten Japanese Text Recognition

This paper presents a model of Deep Convolutional Recurrent Network (DCRN) for recognizing offline handwritten Japanese text lines without explicit segmentation of characters. Most of traditional offline handwritten Japanese text recognizers perform segmentation of text image into characters before individually recognizing each character. Although segmentation by recognition and context are employed to recover from segmentation errors, errors made at this stage directly make an impact on the performance of the whole system. The DCRN model consists of three parts: a convolutional feature extractor using Convolutional Neural Network (CNN) and sliding window to extract features from text image; recurrent layers using BLSTM to predict pre-frame from an input sequence; and a transcription layer using a CTC-decoder to translate the predictions into the label sequence. Experimental results on the database: TUAT Kondate database demonstrates the effectiveness of the proposed method.