Towards an efficient framework for Data Extraction from Chart Images

TL;DR

This paper presents a comprehensive computer vision-based framework for extracting data from chart images, improving detection accuracy and semantic data conversion without heuristic assumptions.

Contribution

It introduces a robust deep learning approach for plot element detection and a novel network for legend matching, advancing chart data extraction methods.

Findings

High-precision box detection using deep learning

Effective point detection with feature fusion networks

Improved data conversion accuracy in chart analysis

Abstract

In this paper, we fill the research gap by adopting state-of-the-art computer vision techniques for the data extraction stage in a data mining system. As shown in Fig.1, this stage contains two subtasks, namely, plot element detection and data conversion. For building a robust box detector, we comprehensively compare different deep learning-based methods and find a suitable method to detect box with high precision. For building a robust point detector, a fully convolutional network with feature fusion module is adopted, which can distinguish close points compared to traditional methods. The proposed system can effectively handle various chart data without making heuristic assumptions. For data conversion, we translate the detected element into data with semantic value. A network is proposed to measure feature similarities between legends and detected elements in the legend matching phase. Furthermore, we provide a baseline on the competition of Harvesting raw tables from Infographics. Some key factors have been found to improve the performance of each stage. Experimental results demonstrate the effectiveness of the proposed system.