At present, paper-based reading and writing are still important ways to learn and record knowledge. People usually rely on text entry on a keyboard to search for interpretations about the puzzled content while reading. So, based on the micro camera and inertial sensor, we designed SmartPen, a low-cost reading assistant tool supporting text or image capture, recognition, and search. The experimental results show that SmartPen can help users read publications conveniently and efficiently. Copyright © 2018 is held by the owner/author(s).