This work is based on Shafer's Dichromatic Reflection Model as applied to color image formation. The color spaces RGB, XYZ, CIELAB, CIELUV, rgb, l1l2l3, and the new h1h2h3 color space are discussed from this perspective. Two color similarity measures are studied: the Euclidean distance and the vector angle. The work in this thesis is motivated from a practical point of view by several shortcomings of current methods. The first problem is the inability of all known methods to properly segment objects from the background without interference from object shadows and highlights. The second shortcoming is the non-examination of the vector angle as a distance measure that is capable of directly evaluating hue similarity without considering intensity especially in RGB. Finally, there is inadequate research on the combination of hue- and intensity-based similarity measures to improve color similarity calculations given the advantages of each color distance measure. These distance measures were used for two image understanding tasks: edge detection, and one strategy for color image segmentation, namely color clustering. Edge detection algorithms using Euclidean distance and vector angle similarity measures as well as their combinations were examined. The list of algorithms is comprised of the modified Roberts operator, the Sobel operator, the Canny operator, the vector gradient operator, and the 3x3 difference vector operator. Pratt's Figure of Merit is used for a quantitative comparison of edge detection results. Color clustering was examined using the k-means (based on the Euclidean distance) and Mixture of Principal Components (based on the vector angle) algorithms. A new quantitative image segmentation evaluation procedure is introduced to assess the performance of both algorithms. Quantitative and qualitative results on many color images (artificial, staged scenes and natural scene images) indicate good edge detection performance using a vector version of the Sobel operator on the h1h2h3 color space. The results using combined hue- and intensity-based difference measures show a slight improvement qualitatively and over using each measure independently in RGB. Quantitative and qualitative results for image segmentation on the same set of images suggest that the best image segmentation results are obtained using the Mixture of Principal Components algorithm on the RGB, XYZ and rgb color spaces. Finally, poor color clustering results in the h1h2h3 color space suggest that some assumptions in deriving a simplified version of the Dichromatic Reflectance Model might have been violated.

This work is based on Shafer's Dichromatic Reflection Model as applied to color image formation. The color spaces RGB, XYZ, CIELAB, CIELUV, rgb, l1l2l3, and the new h1h2h3 color space are discussed from this perspective. Two color similarity measures are studied: the Euclidean distance and the vector angle. The work in this thesis is motivated from a practical point of view by several shortcomings of current methods. The first problem is the inability of all known methods to properly segment objects from the background without interference from object shadows and highlights. The second shortcoming is the non-examination of the vector angle as a distance measure that is capable of directly evaluating hue similarity without considering intensity especially in RGB. Finally, there is inadequate research on the combination of hue- and intensity-based similarity measures to improve color similarity calculations given the advantages of each color distance measure. These distance measures were used for two image understanding tasks: edge detection, and one strategy for color image segmentation, namely color clustering. Edge detection algorithms using Euclidean distance and vector angle similarity measures as well as their combinations were examined. The list of algorithms is comprised of the modified Roberts operator, the Sobel operator, the Canny operator, the vector gradient operator, and the 3x3 difference vector operator. Pratt's Figure of Merit is used for a quantitative comparison of edge detection results. Color clustering was examined using the k-means (based on the Euclidean distance) and Mixture of Principal Components (based on the vector angle) algorithms. A new quantitative image segmentation evaluation procedure is introduced to assess the performance of both algorithms. Quantitative and qualitative results on many color images (artificial, staged scenes and natural scene images) indicate good edge detection performance using a vector version of the Sobel operator on the h1h2h3 color space. The results using combined hue- and intensity-based difference measures show a slight improvement qualitatively and over using each measure independently in RGB. Quantitative and qualitative results for image segmentation on the same set of images suggest that the best image segmentation results are obtained using the Mixture of Principal Components algorithm on the RGB, XYZ and rgb color spaces. Finally, poor color clustering results in the h1h2h3 color space suggest that some assumptions in deriving a simplified version of the Dichromatic Reflectance Model might have been violated.

Thesis (MscAgric (Horticulture))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: For many apple (Malus domestica Borkh.) and pear (Pyrus communis L.) cultivars, attractive colour is essential to their profitability on export markets. This study focuses on problems related to poor green colour of ‘Granny Smith’ apples and insufficient red colour of bi-coloured pear cultivars. ‘Granny Smith’ apples often suffer from poor green colour. Green colour of fruit from various orchards was already found to differ midway through fruit development, with these differences being carried through to harvest. In a trial where nitrogen (N) fertilisers were applied using different forms at different times, there was no improvement in green colour. In another trial, artificial shading was applied to fruit only during their early development. Fruit that were shaded during this time were less green at harvest than unshaded fruit. Additional N applications may only improve colour where a deficiency exists. However, green colour may be improved by increasing light distribution early during fruit development. Bi-coloured pears attain their maximum red colour midway through their development, and this desired red colour is mostly lost prior to harvest. Red colour can also increase transiently with the passing of cold fronts. Anthocyanins, responsible for this red colour, may have a photoprotective function which would explain this pigmentation pattern, as photosystems are particularly sensitive to light damage at low temperatures. As ‘Rosemarie’ fruit bent over from a vertical to hanging position during development, peel photoinhibition was reduced as anthocyanins were synthesised. ‘Forelle’ peel was found to be very sensitive to high light levels at low temperatures. Substantial anthocyanin development took place in ‘Cripps’ Pink’ apples when weather conditions were cold, but clear following a cold front. A photoprotective role seems to explain daily changes in anthocyanins in response to temperature, but not the seasonal progression of colour development. For many apple (Malus domestica Borkh.) and pear (Pyrus communis L.) cultivars, attractive colour is essential to their profitability on export markets. This study focuses on problems related to poor green colour of ‘Granny Smith’ apples and insufficient red colour of bi-coloured pear cultivars. ‘Granny Smith’ apples often suffer from poor green colour. Green colour of fruit from various orchards was already found to differ midway through fruit development, with these differences being carried through to harvest. In a trial where nitrogen (N) fertilisers were applied using different forms at different times, there was no improvement in green colour. In another trial, artificial shading was applied to fruit only during their early development. Fruit that were shaded during this time were less green at harvest than unshaded fruit. Additional N applications may only improve colour where a deficiency exists. However, green colour may be improved by increasing light distribution early during fruit development. Bi-coloured pears attain their maximum red colour midway through their development, and this desired red colour is mostly lost prior to harvest. Red colour can also increase transiently with the passing of cold fronts. Anthocyanins, responsible for this red colour, may have a photoprotective function which would explain this pigmentation pattern, as photosystems are particularly sensitive to light damage at low temperatures. As ‘Rosemarie’ fruit bent over from a vertical to hanging position during development, peel photoinhibition was reduced as anthocyanins were synthesised. ‘Forelle’ peel was found to be very sensitive to high light levels at low temperatures. Substantial anthocyanin development took place in ‘Cripps’ Pink’ apples when weather conditions were cold, but clear following a cold front. A photoprotective role seems to explain daily changes in anthocyanins in response to temperature, but not the seasonal progression of colour development. Dwarfing rootstocks are known to improve red colour of bi-coloured pears due to improved light distribution. ‘Forelle’ fruit from six rootstocks of varying vigour were harvested from exposed positions only, so as to establish the effect of rootstock on red colour development independent of the effect of rootstock on canopy light distribution. Fruit from trees on quince (Cydonia oblonga Mill.) rootstocks were found to have redder fruit than those from vigorous BP pear rootstocks. This may be due to higher chlorophyll and carotenoid concentrations present in the peel of fruit from BP rootstocks, whose leaf and peel N were also high. The use of quince rootstocks is recommended where red colour development of bi-coloured pears is a problem. An early season bi-coloured cultivar with good red colour is required. Breeding trials to find such a cultivar are resource intensive. To streamline the process, a method to preselect immature seedlings for their future fruit colour is required. Fruit colour from bearing seedlings was compared with colour of their immature leaves. Trees with red leaves were likely to produce fruit that were too red for the breeders’ requirements. Trees with green or blushed leaves were capable of producing blushed fruit. It would be feasible to cull red-leaved seedlings with minimal risk of losing potential bi-coloured cultivars. / AFRIKAANSE OPSOMMING: Verskeie appel (Malus domestica Borkh.) en peer (Pyrus communis L.) kultivars se winsgewendheid word bepaal deur hul aantreklike kleur. In hierdie studie word die swak groen kleur van ‘Granny Smith’ appels asook rooi kleurontwikkeling van blospere ondersoek. Die groen kleur van ‘Granny Smith’ appels is dikwels onvoldoende. Verskille in groen kleur tussen boorde was reeds gedurende vroeë vrugontwikkeling aanwesig, en hierdie verskille het voortgeduur tot met oes. Groen kleur kon nie deur verskillende bronne en tye van stikstofbemesting verbeter word nie. Stikstofbemesting verbeter groen kleur moontlik net in boorde met ‘n stikstoftekort. Vrugte wat gedurende hul vroeë ontwikkeling oorskadu is, se groen kleur was swakker by oes in vergelyking met vrugte wat nie oorskadu is nie. Groen kleur kan moontlik verbeter word deur ligverspreiding tydens vroeë vrugontwikkeling deur middel van snoei aksies te verhoog. Blospeerkultivars bereik hul maksimum rooi kleur halfpad deur hul ontwikkeling, maar is geneig om hul rooi kleur grootliks voor oes te verloor. Rooi kleur mag egter kortstondig toeneem in reaksie op die lae temperature gepaardgaande met koue fronte. Antosianiene, wat verantwoordelik is vir die rooi kleur, het moontlik ‘n beskermende funksie teen hoë ligvlakke, en hierdie funksie mag moontlik die bogenoemde patroon van rooikleurontwikkeling verklaar. Die natuurlike buiging van ‘Rosemarie’ pere van hul aanvanklike regop oriëntasie tot hul karakteristieke hangende posisie, is gekenmerk deur ‘n afname in fotoinhibisie van die skil en ‘n gelyklopende sintese van antosianien. ‘Forelle’ skil was uiters sensitief vir hoë ligvlakke in kombinasie met lae temperature (16 ºC). ‘Cripps’ Pink’ appels het ‘n vinnig toename in rooi kleur getoon met die koue, maar helder, weerstoestande wat gevolg het op ‘n kouefront. Dit is welbekend dat dwergende onderstamme die rooi kleur van blospere verbeter deur ligverspreiding in die boom te verhoog. Ten einde die effek van onderstam op rooi kleurontwikkeling onafhanklik van die effek van onderstam op ligverspreiding te ondersoek, is ‘Forelle’ pere wat blootgestel was aan vol son geoes van bome geënt op ses onderstamme met verskillende groeikrag. Kweperonderstamme (Cydonia oblonga Mill.) het rooi kleur verbeter in vergelyking met die groeikragtige BP peeronderstamme. ‘n Moontlike rede vir die verbetering is die laer chlorofiel- en karotenoïedkonsentrasies in die skil van vrugte op kweperonderstamme. Bome op peeronderstamme het ook hoër blaaren skil stikstofvlakke gehad. Kweperonderstamme word aanbeveel in gevalle waar rooi kleurontwikkeling van blospere ‘n probleem mag wees. Die RSA vrugtebedryf benodig ‘n vroeë blospeerkultivar met goeie rooi kleurontwikkeling. Die teling van so ‘n kultivar is hulpbronintensief en baie duur. Ten einde die teelproses meer effektief te maak, word ‘n metode benodig om saailinge al voor uitplanting in die boord te selekteer na gelang van hul toekomstige vrugkleur. Die vrugkleur van oesryp pere van draende saailinge is vergelyk met die kleur van hul onvolwasse blare. Bome met rooi blare is geneig om vrugte te dra wat té rooi is om te kwalifiseer as blospere. Die meerderheid blospere is afkomstig van bome met blos of groen onvolwasse blare. Dit is prakties haalbaar om rooiblaarsaailinge uit te dun, met net ‘n klein, aanvaarbare risiko om ‘n moontlike blospeerkultivar in die proses te verloor. / medg2010-1 / Imported from http://etd.sun.ac.za April 2010.

The majority of the studies reviewed so far indicated that individual subject variables interact with stimulus variables in order to produce human response to color.

Resumen en inglés This thesis presents the color as a dynamic formal element with the ability to be part of the visual language within a specific context, the pictorial treatment. An investigation into the color and its various contributions to plastic and visual language. On the one hand, a study on the color dynamics which determines the factors of both physical perceptual process, as physiological, researching the development of the dynamic qualities of color that help form a conceptual framework. And on the other side from the practice, which enable testing methods, techniques and concepts that enable the development of the dynamics of color in the visual language, incorporating the movement of color into a pictorial speech and visual communication. It has tried to narrow within a specific research field of color, pictorial support. In it, we have developed three projects in order to control the dynamic color capabilities, testing, replicating experiences and drawing conclusions that help develop methods and concepts applied to the dynamics of color in the painting process. Each of the studies corresponds to different goals but they are complementary in the communication process. In a first study the dynamic possibilities of color are analyzed from its physical dimension, investigating the interaction between light color and color pigment. An approach to activity light and the pigment in different historical moments that have contributed values to the basics of color. In a second study these acquired skills are made available by applying the pictorial language in the environment of artistic creation. a painting project called "Wide spectrum light painting" or "painting WSL. Type of painting based on the interaction of light with matter. The wide spectrum light painting develops images based lighting control and behavior of materials. The interaction between light and pigments propose a research field in the work as communicative process. In a third study, a project serving mainly the perceptual aspect of color dynamics is performed. The design of a perceptual dome which allows the study of aspects such as the relationship between the viewer and the work to perceptual level, development of visual language from the painting WSL exhibition and the use of the dome as a pictorial support. This section has also sought to reflect the importance of designing not only the spatial composition of the work but its temporary composition. The colors become part of the movement so dependent progression, in that order before and after it. Spatiotemporal perception that shapes the performance of color. We have seen the relativity of colors depending on their location, changing its perception as a musical note changes its sense depending on where you are. As timing control allows analysis of the interaction of the colors and the appearance of post-images. From these three projects, the underlying objective has been to facilitate the treatment of the dynamics of color as a formal element in the image composition looking to open new ways in expressive and aesthetic values. / Resumen castellano La presente tesis expone el color como elemento formal dinámico con la capacidad de formar parte del lenguaje visual dentro de un contexto concreto, el tratamiento pictórico. Una investigación sobre el color y sus diferentes aportaciones al lenguaje plástico y visual. Por un lado, un estudio sobre la dinámica del color el cual determina los factores del proceso perceptivo tanto físicos, como fisiológicos, investigando el desarrollo de las cualidades dinámicas del color que ayuden a formar un marco conceptual. Y por otro lado desde la praxis, se presentan ensayos donde habilitar métodos, técnicas y conceptos que permitan el desarrollo de la dinámica del color en el lenguaje plástico, incorporando el movimiento del color al discurso pictórico y a la comunicación visual. Se ha tratado de acotar dentro de un campo de investigación específico del color, el soporte pictórico. En él, hemos desarrollado tres proyectos con la finalidad de controlar las capacidades dinámicas del color, haciendo pruebas, reproduciendo experiencias y extrayendo conclusiones que ayuden a desarrollar métodos y conceptos aplicados a la dinámica del color dentro del proceso pictórico. Cada uno de los estudios corresponde a objetivos diferentes sin embargo son complementarios dentro del proceso comunicativo. En un primer estudio se analizan las posibilidades dinámicas del color desde su dimensión física, investigando la interacción entre el color luz y el color pigmento. Se contextualiza la actividad de la luz y del pigmento en diferentes momentos históricos que han aportado valores a los fundamentos del color. En un segundo estudio estas capacidades adquiridas se ponen a disposición del lenguaje pictórico aplicándolo en el entorno de creación artística. Se desarrolla un proyecto de pintura denominado "Pintura de amplio espectro lumínico" o también "Pintura WSL.1 Tipología de pintura basada en la interacción de la luz con la materia. La pintura de amplio espectro lumínico trata la imagen en función del control de la iluminación y el comportamiento de los materiales. La interacción entre la luz y los pigmentos proponen un campo de investigación en la obra como proceso comunicativo. En un tercer estudio se realiza un proyecto atendiendo principalmente al aspecto perceptivo de la dinámica del color. Se realiza el diseño de una cúpula perceptiva la cual permita el estudio de aspectos como la relación entre el espectador y la obra a nivel perceptivo, el desarrollo del lenguaje visual a partir de la exposición de pintura WSL y la utilización de la cúpula como soporte pictórico. En este apartado se ha buscado también reflejar la importancia de diseñar no solo la composición espacial de la obra sino su composición temporal. Los colores pasan a formar parte del movimiento por lo que dependen de la progresión, en que orden se preceden y suceden. Percepción espacio-temporal que configura la actuación del color. Hemos podido comprobar la relatividad de los colores dependiendo de su ubicación, cambiando su percepción al igual que una nota musical varía su sensación según el lugar donde se encuentre. Por lo que el control temporal permite el análisis de la interacción de los colores y de la formación de post-imágenes. A partir de estos tres proyectos, el objetivo consiguiente ha sido facilitar el tratamiento de la dinámica del color como elemento formal en la composición de la imagen buscando abrir nuevas vías en valores expresivos y estéticos. / Resumen en valenciano La present tesi exposa el color com a element formal dinàmic amb la capacitat de formar part del llenguatge visual dins d'un context concret, el tractament pictòric. Una investigació sobre el color i les seues diferents aportacions al llenguatge plàstic i visual. D'una banda, un estudi sobre la dinàmica del color el qual determina els factors del procés perceptiu tant físics, com fisiològics, investigant el desenvolupament de les qualitats dinàmiques del color que ajuden a formar un marc conceptual. I per un altre costat des de la praxi, es presenten assajos on habilitar mètodes, tècniques i conceptes que permeten el desenrotllament de la dinàmica del color en el llenguatge plàstic, incorporant el moviment del color al discurs pictòric i a la comunicació visual. S'ha tractat de fitar dins d'un camp d'investigació específic del color, el suport pictòric. En ell, hem desenrotllat tres projectes amb la finalitat de controlar les capacitats dinàmiques del color, fent proves, reproduint experiències i extraient conclusions que ajuden a desenrotllar mètodes i conceptes aplicats a la dinàmica del color dins del procés pictòric. Cada un dels estudis correspon a objectius diferents no obstant això són complementaris dins del procés comunicatiu. En un primer estudi s'analitzen les possibilitats dinàmiques del color des de la seua dimensió física, investigant la interacció entre el color llum i el color pigment. Es contextualitza l'activitat de la llum i del pigment en diferents moments històrics que han aportat valors als fonaments del color. En un segon estudi estes capacitats adquirides es posen a disposició del llenguatge pictòric aplicant-ho en l'entorn de creació artística. Es desenrotlla un projecte de pintura denominat "Pintura d'ampli espectre lumínico" o també Pintura WSL1. Tipologia de pintura basada en la interacció de la llum amb la matèria. La pintura d'ampli espectre lumínic tracta la imatge en funció del control de la il·luminació i el comportament dels materials. La interacció entre la llum i els pigments proposen un camp d'investigació en l'obra com a procés comunicatiu. En un tercer estudi es realitza un projecte atenent principalment a l'aspecte perceptiu de la dinàmica del color. Es realitza el disseny d'una cúpula perceptiva la qual permeta l'estudi d'aspectes com la relació entre l'espectador i l'obra a nivell perceptiu, el desenrotllament del llenguatge visual a partir de l'exposició de pintura WSL i la utilització de la cúpula com a suport pictòric. En este apartat s'ha buscat també reflectir la importància de dissenyar no sols la composició espacial de l'obra sinó la seua composició temporal. Els colors passen a formar part del moviment pel que depenen de la progressió, en que orde es precedixen i succeïxen. Percepció espai-temporal que configura l'actuació del color. Hem pogut comprovar la relativitat dels colors depenent de la seua ubicació, canviant la seua percepció igual que una nota musical varia la seua sensació segons el lloc on es trobe. Pel que el control temporal permet l'anàlisi de la interacció dels colors i de la formació de post-imatges. A partir d'estos tres projectes, l'objectiu consegüent ha sigut facilitar el tractament de la dinàmica del color com a element formal en la composició de la imatge buscant obrir noves vies en valors expressius i estètics. / Bellod Ortuño, G. (2017). Dinámica del color en la pintura. Prácticas plásticas y visuales [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/78979 / TESIS

Blue light filters have become commonplace in modern technology. While there has been a substantial amount of research into their effects on sleep, there has been little into the effect on the media perceived through them. This study sought to examine whether the mechanisms responsible for the adaptation to ambient light conditions would counteract this effect. To do so, a digital survey was conducted in which participants rated 30 colors on 3 different emotional attributes: warmth, weight, and activity. Participants took the survey with or without a blue light filter active, and with or without external light. The external light was intended to eliminate or reduce the level of adaptation to the screen’s altered colors. After comparison between the groups, it was revealed that no significant subjective difference appeared between either of the test conditions. However, with external light, there was a difference in perceived warmth with and without the blue light filter. This implies that some sort of adaptation is involved, and is interfered with by qualities of ambient light. The prevalence of these usage conditions is left to future research, as is whether the specific extent of the difference caused by blue light filters is significant enough to design around. / Blåljusfilter har blivit vanliga i modern teknik. Även om det har gjorts en betydande mängd forskning om deras effekter på sömn, har det varit lite om effekten på media som uppfattas genom dem. Denna studie försökte undersöka om de mekanismer som är ansvariga för anpassningen till omgivande ljusförhållanden skulle motverka denna effekt. För att göra det genomfördes en digital undersökning där deltagarna betygsatte 30 färger på 3 olika känslomässiga egenskaper: värme, vikt och aktivitet. Deltagarna gjorde undersökningen med eller utan ett aktivt blåljusfilter och med eller utan externt ljus. Det yttre ljuset var avsett att eliminera eller minska nivån av anpassning till skärmens ändrade färger. Efter jämförelse mellan grupperna avslöjades att ingen signifikant subjektiv skillnad förekom mellan någon av testbetingelserna. Men med externt ljus var det skillnad i upplevd värme med och utan blåljusfiltret. Detta innebär att någon form av anpassning är inblandad och störs av egenskaperna hos omgivande ljus. Förekomsten av dessa användningsförhållanden överlämnas till framtida forskning, liksom om den specifika omfattningen av skillnaden som orsakas av blåljusfilter är tillräckligt stor för att kunna designas runt.

Detta examensarbete undersöker vilken betydelse färgval har utifrån skapade reklaminslag, anpassat för Instagram. Vi utgår från några grundläggande begrepp om visuell färguppfattning som har sitt ursprung i färgteori, färgpsykologi, färgsystem och färguppfattning. Vi tar också hänsyn till den digitala marknadsföringen och dess betydelse samt tar hjälp av tidigare forskning inom färgperception och marknadsföring. Syftet med arbetet är att presentera statistik och dataanalys i användningen av olika färgsättningar på bilder i olika sammanhang, för att visa hur färgsättningen i en bild har betydelse för vilka känslor och associationer som väcks hos användaren. Undersökningen använder ett Instagramutseende för att presentera fyra stycken utvalda bilder, två på tema turism och två på tema konsert, där vi sedan applicerar färgerna; gul, röd, blå eller grön. Respondenterna i webbenkäten fick bedöma hur de associerar bilden utifrån de redan framtagna alternativen som finns till varje fråga i enkäten. Undersökningens resultat visar att färgen i en bild har stor betydelse när det gäller associationer och känslor. Det blir viktigt att välja rätt färg i den digitala marknadsföringen för att fånga Instagram-användarens uppmärksamhet och för att skapa intryck hos användaren, för att på så sätt öka inläggets popularitet och förstärka och matcha dess budskap. / This degree project examines the significance of the color choice based on created advertising elements, adapted for Instagram. We start from some basic concepts of visual color perception that have their origins in color theory, color psychology, color systems and color perception. We also take digital marketing and its importance into account and use previous research in color perception and marketing. The purpose of this study is to present statistics and data analysis in the use of different colorings on images in different contexts, to show how the coloring in an image is important for the feelings and associations that are evoked in the user. The survey uses an Instagram layout to present four selected images, two on the theme of tourism and two on the theme of concert, where we then apply the colors; yellow, red, blue or green. The respondents in the web survey had to assess how they associate the image based on the already created alternatives that are available for each question in the survey. The results of the survey show that the color in an image has great significance in terms of associations and feelings. It becomes important to choose the right color in digital marketing to capture the attention of the Instagram user and to create an impression on the user, thus increasing the popularity of the post and reinforcing and matching its message.

Most of the drinking water supply in rural Bangladesh comes from groundwater collected using shallow tubewells. The tubewells, usually shallow because of the increased cost involved in deeper tubewells, have been installed by local drillers. A Sediment Color Tool was developed, with input from local drillers, that associated the arsenic concentration with specific sediment colors, in order to help the drillers install safe tubewells. This tool was digitized into the phone application, ASMITAS, to reduce subjectivity in sediment color determination due to human error or surrounding conditions, when used with a color sensor. The purpose of this study was to carry out a preliminary assessment of the application performance and usability, and the results provided by the application for color identification. 35 sediments were used and assigned into 4 different data sets to allow for comparison. Two data sets were assigned a Munsell color manually, while two were assigned the Munsell Soil Color (or Red-Green-Blue color) through use of the digital app. The sensor, the Nix Color Sensor Pro 2, was validated through a literature review and is considered accurate in identifying the color of the soil sediments. The data sets were compared based on the Delta E 2000 formula to determine the color difference between the data sets. The most relevant result of this method was between the Red-Green-Blue that the Nix Sensor originally provided to the application versus the closest matching Munsell code that the application could provide. It showed that the library from which the Munsell color was drawn was not yet expansive enough to accurately identify all sediments that may be scanned. Cyan-Magenta-Yellow-Black color comparisons were made to ascertain which aspects of the color are the most difficult to identify. It was found that both the sensor and the human eye had difficulties in identifying differences in the yellow percentage of several of the samples. The results showed that there may be greater need for distinction of which yellow percentages of Cyan-Magenta-Yellow-Black belong to which color sediment. Overall, the application appears to have a small number of less prominent features and functions to improve on prior to the publication of the application. At this stage of development, the main goal lies in the improvement and building of the Munsell color code reference library and the library of arsenic concentrations associated with each sediment color within the application, in order to improve the accuracy of the results. / Största delen av dricksvattenförsörjningen i lantlig Bangladesh kommer från grundvatten som samlas in med rörbrunnar. Rörbrunnarna, som vanligtvis är grunda som en följd av kostnaderna, har installerats av lokala borrare. Under 2007 antogs det att färgen på sedimentet i vilket rörbrunnarna placeras ger en indikation på arsenikens koncentration. Därför utvecklades Sediment Color Tool med input från de lokala borrarna. Verktyget vidareutvecklades till en digital app, ASMITAS, för att minska subjektiviteten i markfärgbestämning på grund av mänskliga fel eller omgivande förhållanden. Syftet med denna studie var att utvärdera applikationens prestanda i detta stadie av dess utveckling och färgidentifiering som genomförts av applikationen. 35 sediment användes i första bedömningen och klassificerades fyra gånger i fyra olika datamängder för att möjliggöra jämförelse. Två datamängder tilldelades en Munsell Soil Color manuellt, medan två tilldelades sin färg genom användning av den digitala appen. Sensorn som användes, Nix Color Sensor Pro 2, validerades genom en litteraturöversikt och anses vara korrekt när det gäller att identifiera färgen på sediment. De fyra datamängderna jämfördes visuellt med användning av färgbrickor. De jämfördes baserat på DE2000-formeln för att bestämma färgskillnaden mellan datamängden. Det mest avslöjande resultatet med denna metod var mellan dem två digitalt förvärvade datamängderna. Resultatet föreslår att referensbiblioteket i ASMITAS, från vilket matchen togs, ännu inte var tillräckligt stort för att identifiera alla sedimentprover noggrant för att ej vara märkbar för det mänskliga ögat. Cyan-Magenta-Gul-Svart jämförelser gjordes för att se vilka aspekter av färgen som är svårast att identifiera. Resultaten visade att både sensorn och det mänskliga ögat hade svårigheter att identifiera skillnader i den gula procentandelen av flera av proverna och sedimentfärgerna. Resultaten visade att det kan finnas ett större behov av åtskillnad av vilka gula procentsatser som tillhör vilken färg av sediment (och motsvarande arsenikkoncentration). Det finns ytterligare aspekter och funktioner av appen som är mindre centrala för dess prestanda som bör förbättras innan applikationen publiceras. I detta utvecklingsstadium ligger emellertid huvudmålet i förbättring och uppbyggnad av Munsell- färgkodreferensbiblioteket och biblioteket med arsenik-koncentrationer som är kopplad till varje sedimentfärg i applikationen. Detta för att öka resultatets noggrannhet.

Call number: LD2668 .T4 1960 S36

Call number: LD2668 .T4 1963 W33