Chinese Character Boxes: Single Shot Detector Network for Chinese Character Detection

Junhwan Ryu,Sungho Kim

doi:10.3390/app9020315

Abstract

This paper proposes a deep learning-based Chinese character detection network which is important for character recognition and translation. Detecting the correct character area is an important part of recognition and translation. Previous studies have focused on methods using projection through image pre-processing and recognition methods based on segmentation and methods using hand-crafted features such as analyzing and using features. Unfortunately, the results are vulnerable to noise. Recently, recognition or translation systems based on deep learning were dealt with as a single step from detection to translation but they failed to consider the inaccurate localization problem that arises in detectors. This paper proposes a Chinese character boxes (CCB) network that deals with a method to detect the character area more accurately using the single-shot multibox detector (SSD) as the baseline and called CCB-SSD. The proposed CCB-SSD network has a single prediction layer structure in which unnecessary layers are removed from the feature-pyramid structure. The augmentation method for training is introduced and the problem caused by the use of default boxes is solved by using the proposed non-maximum suppression (NMS). The experimental results revealed a 96.1% detection rate and 0.89 performance against the false positives per character (FPPC) which is the proposed false positive index for the character data-set and caoshu data-set used in this paper. This method showed better performance than the conventional SSD with 69.4% and 6.57 FPPC.

Highlights

Many studies have been conducted to solve optical character recognition (OCR) problems but challenging problems still remain due to various external factors such as the type and boldness of the handwriting, the size of the document, the degree of damage to the document, and the background of the document
This paper proposes a Chinese character boxes (CCB) network for character area detection based on a single-shot multibox detector (SSD) [1] called character boxes-single shot multibox detector (CCB-SSD) to detect each character of an old document
This section introduces CCB-SSD network which is a network for Chinese character detection and compares the performance according to restrict of random parameters used for data synthesis, and introduces augmentation method of cropped form and document type data

Summary

Introduction

Many studies have been conducted to solve optical character recognition (OCR) problems but challenging problems still remain due to various external factors such as the type and boldness of the handwriting, the size of the document, the degree of damage to the document, and the background of the document. The preservation environment can cause damage or severe noise. These problems are very difficult to detect and recognize using conventional methodologies. Caoshu differs in shape according to the author and has a different form from that of Figure 1a which is the standard Chinese character type today

Methods

Results

Conclusion