Digitizing of analogue data-charts from thermohygrographs

• Autorzy: Radoń J.
• Języki publikacji: EN

Abstrakty

EN

A thermo-hygrograph is a chart recorder that measures and records both temperature and humidity in an analogue form. Converting the results into digital form is necessary to enhance evaluation of measurements archived on paper charts. Coordinate system of the charts is different than common Cartesian rectangular axis. Temperature and relative humidity axis are curved according to recorder pen holder ray. Different chart types, depending on particular thermohygrograph model, were used so far. In every case, however, the axis grid depicted in the background is geometrically precisely defined. So pattern recognition techniques could be used to find its location automatically. Temperature and relative humidity patterns can be retrieved automatically assuming that the color group of plotted lines is different than the background including the grid. Due to storing conditions, manual descriptions, discoloration and other factors, the plotted pattern cannot be unambiguously identified. Many randomly scattered pixels are interpreter as being part of a plotted line. Among additional measures, like excluding particular areas from analysis, manually removing and including points, a vector analysis of retrieved courses makes digitizing more effective.

Słowa kluczowe

EN

thermohygrograph chart; digitizing; software algorithm

PL

higrogram; digitalizacja; algorytm oprogramowania

• Wydawca: Wydawnictwo Politechniki Łódzkiej
• Czasopismo: Journal of Applied Computer Science
• Rocznik: 2017
• Tom: Vol. 25, nr 1
• Strony: 49--60
• Opis fizyczny: Bibliogr. 5 poz., il. kolor., 1 rys., wykr.

Twórcy

autor

Radoń J.

• Engineering Consulting & Software Development, Balicka 140D, 30-149 Kraków/Poland

Bibliografia

• [1] Digitizing programs for Converting Hard Copy Graphs and Plots back to Data, accessed 30.06.2016.
• [2] Ziou, D. and Tabbone, S., Edge Detection Techniques - An Overview, International Journal of Pattern Recognition and Image Analysis, 1998.
• [3] A. Jaklic, L. Sajn, G. D. P. P., Automatic digitization of pluviograph strip charts, Meteorological Applications, Meteorological Applications 23, 2016, pp. 57-64.
• [4] Gscanth software, Internet, http://dufters.de/Alfred/Xari/gscanth/, accessed 12.07.2016.
• [5] Jahne, B., Digital Image Processing, Springer-Verlag, 2002.

Uwagi

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).