Journal of the Semiconductor & Display Technology (반도체디스플레이기술학회지)

The Korean Society Of Semiconductor & Display Technology (한국반도체디스플레이기술학회)
권호 표지

7-Segment Optical Character Recognition Using Template Matching

템플릿 매칭을 이용한 7-세그먼트 광학 문자 인식

  • Jung, Min Chul (Dept. of Electronic Engineering, Sangmyung University)
  • 정민철 (상명대학교 공과대학 전자공학과)
  • Received : 2020.12.17
  • Accepted : 2020.12.22
  • Published : 2020.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

This paper proposes a new method for the digit recognition on a 7-segment display. The proposed method uses morphological processing that dilates segments of digits and connects them into strokes. The digits are extracted by connected component analysis and finally, template matching method recognizes the extracted digits. The proposed method is implemented using C language in Raspberry Pi 4 system with a camera module for a real-time image processing. Experiments were conducted by using various 7-segment LED displays and 7-segment mono LCD displays. The results show that the proposed method is successful for the digit recognition on the 7-segment displays.

Keywords

References

  1. Daeun Dana Kim, Gyun Hyuk Lee, Je-Kyoung Yem, Sang Kyu Jang, Muhammad Tanseef Shahid, Kwang Nam Choi, "Autonomous Drone Control System using 7-Segment Number Detection," Proceedings of The KIISE Conferences, The Korean Institute of Information Scientists and Engineers, pp. 1863-1864, (2017).
  2. N. Otsu, "A Threshold Selection Method from Gray Level Histograms," IEEE Transactions on Systems, Man, and Cybernetics, Vol. SMC-9, No. 1, pp. 62-66, (1979). https://doi.org/10.1109/TSMC.1979.4310076
  3. Gyoung-don Joo, Jung-eun Park, Chunyun Kim, "Image Pre-processing using Combination of Morphological Transformation and Adaptive Thresholding based Binarization of High-complexity Image for OCR," Proceedings of The KIISE Conferences, The Korean Institute of Information Scientists and Engineers, pp. 1386-1388, (2017).
  4. Yong Jin Joo, Chang Hahk Hahm, "A Study on Automatic Detection of Speed Bump by using Mathematical Morphology Image Filters while Driving," Journal of Korean Society for Geospatial Information Science, Vol. 21, No. 3, pp. 55-62, (2013)
  5. Seung-Mok Lee, Young-Hyung Kim, Jae-Kwon Eem, "Support-generation Method Using the Morphological Image Processing for DLP 3D Printers," The Journal of Korean Institute of Information Technology, Vol. 15, No. 12, pp. 165-171, (2017). https://doi.org/10.14801/jkiit.2017.15.12.165
  6. H. Samet and M. Tamminen, "Efficient component labeling of images of arbitrary dimension represented by linear bintrees," IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 10, Is. 4, pp. 579-586, (1988). https://doi.org/10.1109/34.3918
  7. M. Dillencourt, H. Samet and M. Tamminen, "A general approach to connected-component labeling for arbitrary image representations," Journal of the Association for Computing Machinery, Vol. 39, Is. 2, pp. 253-280, (1992). https://doi.org/10.1145/128749.128750
  8. M. Nadler and E. Smith, "Pattern Recognition Engineering," John Wiley & Sons Inc., pp. 155-159, 291-294, (1993).