Deep Capsule Network based Automatic Batch Code Identification Pipeline for a Real-life Industrial Application

Abstract

Automatic recognition of text, such as a batch code printed on a box placed on a moving conveyor belt, is still a challenging problem. This paper proposes an end-to-end character recognition technique while addressing the major challenges encountered in a real environment, such as motion blur in the acquired images, slanted or oriented characters, creased batch codes due to wear and tear of boxes, variations in label formats, and variations in printing styles. The major contribution of this work lies in development of three sequential modules: text localization using Connectionist Text Proposal Network(CTPN), character detection and character recognition using a modified version of the capsule network (CapsNet). In contrast to CapsNet, where only a standard single convolution is used, the proposed method uses a series of feature blocks, making it a deep CapsNet which is later proven to generate more comprehensive and better separable feature vectors over its counterpart. The feature generation module is further enhanced by setting a smaller kernel size than CapsNet. The proposed system is validated on a real-world box / packet dataset generated in a retail manufacturing industry. The proposed recognition network architecture is also validated on a standard public dataset (ICDAR 2013). The comparative results are presented with statistical analysis in the experimental results section.