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.
Savolainen, T., Keith Whiter, D., & Partamies, N. (2016). Automatic segmentation and classification of seven-segment display digits on auroral images. Geoscientific Instrumentation, Methods and Data Systems, 5(2), 305–314. https://doi.org/10.5194/gi-5-305-2016