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Title:Teoretični model za opis videnja barvnih krožnic pri vrtenju črno-bele vrtavke
Authors:ID Dimec, Robert (Author)
ID Vaupotič, Nataša (Mentor) More about this mentor... New window
Files:.pdf MAG_Dimec_Robert_2014.pdf (1,16 MB)
MD5: 44A7DE81B0789313EB3920E0EF68CC45
 
Language:Slovenian
Work type:Master's thesis
Typology:2.09 - Master's Thesis
Organization:FNM - Faculty of Natural Sciences and Mathematics
Abstract:Pred približno 120 leti je Benham predstavil vrtavko, katere površina je deljena na beli in črni polkrog. Na belem polkrogu se na različnih oddaljenostih od središča nahajajo črni loki. Pri vrtenju vrtavke vidimo krožnice, na katerih se nahajajo črni loki, v različnih barvnih odtenkih. Pri zamenjavi smeri vrtenja vrtavke se zamenja tudi vrstni red barvnih krožnic. V magistrskem delu predstavimo nekaj različic črno-belih vrtavk, pri katerih med vrtenjem vidimo barvne krožnice, povzamemo raziskave s tega področja in razložimo, kakšno vlogo imajo pri nastanku barvnega vtisa vidne celice, ki se nahajajo na očesni mrežnici (čepki). Na podlagi časovnih (karakteristični aktivacijski in relaksacijski časi) in prostorskih karakteristik (lastnosti receptivnih polj) treh vrst čepkov zgradimo teoretični model za opis videnja barvnih krožnic pri vrtenju črno-bele vrtavke, v katerem privzamemo (i) linearni in (ii) eksponentni odziv čepkov na svetlobni dražljaj. Naše glavno vodilo je, da relativno kompleksne modele ostalih avtorjev poenostavimo v tolikšni meri, da bo linearni model uporaben pri dodatnih vsebinah pouka fizike na gimnazijskem nivoju, eksponentni model pa pri osnovnem kurzu fizike na univerzitetnem nivoju. Izkaže se, da model navkljub poenostavitvi pravilno simulira pojav barvnih krožnic in zamenjavo vrstnega reda barvnih krožnic pri zamenjavi smeri vrtenja vrtavke ter hkrati temelji na znanstveno potrjenih dejstvih, na katerih modele gradijo ostali avtorji. Tako linearni kot eksponentni model zgradimo v treh korakih: v prvem upoštevamo zgolj časovne, v drugem časovne in prostorske karakteristike čepkov, v tretjem pa vhodni signal vrtavke (zaporedja vrednosti, ki jih priredimo črnim in belim območjem na različnih radijih vrtavke) prilagodimo različnim skupinam čepkov. Na tak način prostorske karakteristike čepkov v model vpeljemo v obliki časovnega faktorja. Izkaže se, da oba predlagana modela pravilno napovesta barvne odtenke krožnic, če prehodi med črnimi in belimi območji na vse skupine čepkov ne vplivajo enako. Barvni odtenek, ki ga na določenem radiju vrtavke napove teoretični model, definiramo na podlagi povprečnih vzbujenosti posameznih vrst čepkov. Barvne odtenke krožnic, ki jih dobimo na takšen način, preverimo z RGB barvnim modelom in opozorimo na potencialno pomanjkljivost predstavljenega teoretičnega modela in teoretičnih modelov nekaterih ostalih avtorjev, ki barvne odtenke krožnic, ki jih pri vrtenju inducira črno-bela vrtavka, definirajo na podoben način.
Keywords:Benhamova vrtavka, karakteristični časi čepkov, receptivna polja, teoretični model, RGB barvni model.
Place of publishing:Maribor
Publisher:[R. Dimec]
Year of publishing:2014
PID:20.500.12556/DKUM-44979 New window
UDC:531.383:535.6(043.2)
COBISS.SI-ID:20790536 New window
NUK URN:URN:SI:UM:DK:EML5HHCG
Publication date in DKUM:25.09.2014
Views:2187
Downloads:176
Metadata:XML DC-XML DC-RDF
Categories:FNM
:
DIMEC, Robert, 2014, Teoretični model za opis videnja barvnih krožnic pri vrtenju črno-bele vrtavke [online]. Master’s thesis. Maribor : R. Dimec. [Accessed 4 April 2025]. Retrieved from: https://dk.um.si/IzpisGradiva.php?lang=eng&id=44979
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Secondary language

Language:English
Title:The theoretical model for describing the perception of color circles on a spinning black and white top
Abstract:About 120 years ago, Benham introduced a top, the surface of which is divided into a white and black semicircle. On the white semicircle there are black arches at different radii from the centre. When the top spins, coloured circles are observed at radii where the black arches are located. When the top spins in the opposite direction, the colour of circles changes. In this thesis we present different types of black-and-white spinning tops, summarise the research in this field, and explain the role of photoreceptors (three types of cones) located at the retina in the appearance of colour. On the basis of temporal (characteristic activation and relaxation times) and spatial characteristics (properties of receptive fields) of the three types of cones, we build a theoretical model to describe the perception of colour circles on a spinning black-and-white top, in which we assume (i) linear and (ii) exponential cone response to the light stimuli. Our guiding principle is to simplify relatively complex models of other authors to such an extent that the linear model could be used at lessons of Physics at the grammar school level, and the exponential model at the elementary course of Physics at the university level. It turns out, that the simplified model, which is still based on the scientifically established facts, correctly simulates the colours of circles and the change of order of colour circles when the spinning direction is reversed. Both, the linear and exponential model are built in three steps: first, we consider only temporal, second, temporal and spatial cone characteristics, third, we adjust the input signal of the top (the sequence of values that are assigned to the black and white areas on different radii from the top centre) to different groups of cones. In this way, spatial characteristics of the cones are introduced into the model in the form of a temporal factor. It turns out that both proposed models correctly predict colour hues of circles, if transitions between the black and white areas affect different groups of cones in a different way. The colour hue, which the theoretical model predicts at a given radius, is defined by the average excitation of a given cone type. We compare the colour hues of circles, obtained by the model, with the RGB colour model and highlight the potential disadvantage of the presented theoretical model and theoretical models of some other authors, who study the colour hues of the black-and-white spinning tops.
Keywords:Benham’s top, characteristic response times of cones, receptive fields, theoretical model, RGB colour model.


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