Automatic segmentation and classification of seven-segment display digits on auroral images

Research output: Contribution to journalArticleScientificpeer-review


  • Tuomas Savolainen
  • Daniel Keith Whiter
  • Noora Partamies

Research units

  • University of Southampton
  • University Centre in Svalbard
  • Finnish Meteorological Institute


In this paper we describe a new and fully automatic method for segmenting and classifying digits in seven-segment displays. The method is applied to a dataset consisting of about 7 million auroral all-sky images taken during the time period of 1973-1997 at camera stations centred around Sodankylä observatory in northern Finland. In each image there is a clock display for the date and time together with the reflection of the whole night sky through a spherical mirror. The digitised film images of the night sky contain valuable scientific information but are impractical to use without an automatic method for extracting the date-time from the display. We describe the implementation and the results of such a method in detail in this paper.


Original languageEnglish
Pages (from-to)305-314
Number of pages10
JournalGeoscientific Instrumentation, Methods and Data Systems
Issue number2
Publication statusPublished - 21 Jul 2016
MoE publication typeA1 Journal article-refereed

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