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Making 3D Models Using Close-range Photogrammetry: Comparsion of Cameras and Software
Full text linkBakalaureusetöö
Geodeesia ja maakorralduse õppekavalKäesolevas bakalaureusetöös käsitlen lähifotogramm-meetria kasutusvõimalusi arheoloogias.
Uurimuse eesmärk oli selgitada, kuidas mõjutab 3D mudeli kvaliteeti tarkvara ja kaamera valik. Võrdlesin kolme tarkvara: 1) Pix4D; 2) Agisoft Photoscan ja 3) Visual SFM koos tiheda punktipilve loomise mooduliga Yasutaka Furukawa's CMVS tool. Erineva hinnaklassi ja tehniliste näitajatega kaameraid oli võrdluses neli 1) Canon EOS 760D; 2) Canon EOS 600D; 3) Canon Ixus 185 ja 4) Sony Xperia Z1 nutitelefoni kaamera.
Tegin kõikide kaameratega täpselt samadest pildistamise asukohtadest fotod kahel erineval pildistamissessioonil (kokku 8 komplekti fotosid). Fotodest erinevate tarkvarade abil loodud esmaste 3D mudelite ehk tihedate punktipilvede välimuse võrdlemisel andis parima tulemuse Agisoft Phtoscan: vaid see programm moodustas kõikide kaameratega tehtud piltidest hea katvusega tihedad punktipilved.
Mudelite geomeetrilist kvaliteeti uurisin programmis Agisoft Photoscan tehtud mudelite puhul. Hüpoteesiks oli, et digitaalsed peegelkaamerad tagavad geomeetriliselt täpsema tulemuse kui kompaktkaamerad. Tulemused olid üllatavad. Esimese pildistamiskorra fotodest saadi suurima geomeetrilise veaga mudel kaameraga Canon EOS 760 D pildistatud fotodest (mudeli viga 5,0 mm) ja täpseim mudel kompaktkaamera Canon Ixus 185 abil (viga 3,4 mm). Teise pildistuskorra mudelite vead olid oluliselt suuremad kui esimese pildistuskorra omad. Suurim viga oli 17,9 mm (Sony Xperia Z1) ja vähim 11,2 mm (Canon EOS 600D). Tulemuste põhjendamine on raske, kuna Agisoft Photoscan on suletud koodiga kommertstarkvara.
Antud töös hindasin mudeli geomeetrilist täpsust vaid 16–23 tahhümeetriliselt mõõdistatud kontrollpunkti suhtes. Kuna arheoloogia seisukohast on oluline uuritava objekti kuju võimalikult täpne edasiandmine, võiks edaspidi võrrelda fotogramm-meetriaprogrammi poolt loodud tihedat punktipilve terrestrilise laserskanneerimise abil saadud referentsandmestikuga.In current bachelor theses I observe the use of close-range photogrammetry based on phtos taken by consumer cameras in the field of archaeology.
Aim of the study is to unveil how the choice of software and cameras influences the quality of 3D models. I compared three different softwares: (1) Pix4D (2) agisoft Phtoscan, and (3) Visual SFM with dense cloud module Yasutaka Furukawa's CMVS tool and four different cameras (1) Canon EOS 760D, (2) Canon EOS 600D; (3) Canon Ixus 185, and (4) Sony Xperia Z1 smartphone camerea D5503. Cameras represent different price segments and tehcnical parameters.
I took the photos with all the cameras from identical positions during two photo sessions (obtaining altogether 8 sets of phtos). Comparison of primary 3D models, dense point clouds revealed that in terms of visual appeal, results were the best with Agisoft Phtoscan which was the only software that managed to create visually appealing dense point cloud from photos taken with smartphone camera.
Geometric quality of models was futher investigated using Agisoft Pohotoscan software. My hypothesis was that digital single-lens reflex cameras will perform better in terms of model accuracy. The results were surpising. In case of first photo session, Canon EOS 760D images delivered a model with largest total error (5.9 mm) and model made of phtotos taken with Canon Ixus 185 was the most accurate (total error of the model 3.4
mm). Total errors of the modeles built from images of the second photo session were significantly larger. Worst result was obtained using Sony Xperia Z1 camera (total error 17.9 mm), Canon EOS 600D performed best (total error of the model 11.2 mm) It is hard to interpret the results as Agisoft Photosan is a commercial software with closed source code (so-called “black-box” programme).
In current research I calculated model accuracy in reference to 19–23 check points measured with total station. In archaeology, it is important to document the exact volumes of structures and artefacts, therefore in the future dense 3D point clouds should be compared to reference data obtained with terrestrial laser scanner
Metalworking sites in Estonia during the 7th–17th centuries
Full text linkVäitekirja elektrooline versioon ei sisalda publikatsiooneMineviku metallitöö kuulub nende valdkondade hulka, mille uurimisel on arheoloogia märkimisväärseks teadmiste allikaks. Minu väitekirja eesmärk on anda peamiselt arheoloogilise leiuainese põhjal uut informatsiooni Eesti metallitöö kohta 7.–17. sajandini. Selle perioodi jooksul toimus nii tehnoloogilisi kui poliitilisi arenguid, millest kõige murrangulisemaks võiks pidada 13. sajandi alguse vallutussõda, mille käigus liideti Eesti alad kristliku Euroopaga. Uute linnade loomisega hakkas siia saabuma ka läänes väljaõppe saanud käsitöölisi, kes tõid kaasa omad töövõtted ja tööriistad.
Põhilise allikana käsitlen metallitööpaiku ja sealt pärinevaid tootmisjääke. Rauatöö uurimiseks on suurema tähelepanu all sepikojad, seal asunud ääsid ja sepistamiseks vajaminev raud. Kohaliku rauasulatuse ja sepikodade laialihajutatud paiknemismustri tõttu säilitas maasepikoda oma rauaaegse ilme 14. sajandini. Eriti suure tähelepanu all on 14.–17. sajandisse dateeritud Käku sepikojaase Saaremaal, kuna sealt tuli 2007.-2014. aastal välitööde käigus välja nelja järjestikuse sepikoja ehitusjäänuseid kui hulgaliselt leide. Juba Käku kõige varasem, 14.–15. sajandisse dateeritud, sepikoda meenutab oma põhiplaanilt ja ääsi ehitusviisilt pigem 14. sajandisse dateeritud Haapsalu linna sepikodasid kui 13.–14. sajandi algusesse dateeritud Paatsa maasepikoda, mis viitab maa ja linnaseppade traditsioonide ühtlustumisest. Metallograafiline analüüs Käku sepikoja rauakangidest andis aga teavet selle kohta, et kuidas käitlesid sepad toorrauda ja taaskasutati terasest tööriistu.
Metallivalu puhul analüüsisin eelkõige metallisulatustiigleid, valamiskulpe ja valuvorme ning neis leiduvaid metallijääke kasutades nii portatiivset spektromeetrit (pXRF) kui skaneerivat elektronmikroskoopi (SEM-EDS). Selgus, et nooremal rauaajal oli nii hõbeda kui tina valamine koondunud linnamägedele ja maalinnadesse. Uuritud tiiglikatketest sisaldas 27% hõbeda jääke, mis näitab, et hõbedavalu oli laialt levinud. Peale ristisõda ning uute linnade rajamist asendas linnades tehtud metallivalu varasemalt linnamägedel ja maalinnades tehtud käsitöö. Linnadesse tuuakse ka imporditud tiigleid, kus muude jääkide hulgas on puhta kulla valamise jäägid, mis on kontrastiks rauaaegsele metallivalule.Archaeology can contribute greatly to our understanding of past metalworking. The main goal of this thesis is to provide new information on Estonian metalworking between the 7th–17th centuries, based on archaeological sources. During this period there were political changes and technological developments that impacted Estonian society. The most important event was the 13th century crusade, after which Estonia was brought into Christian Europe. Western craftsmen started to settle into Estonia with the founding of new towns, bringing new techniques and tools as they came.
My main contribution is the study of metalworking sites and the analysis of their production waste. Smithies, forges, iron blooms and bars are all investigated to gain a better understanding of ferrous metalworking. Local iron production and the scattered locations of smithies retained the pre-crusade workshop layout up until the 14th century. The 14th–17th century smithy site of Käku was studied in detail and the excavations between 2007–2014 revealed the remains of four consecutive smithies and thousands of finds. The smithy of Käku more resembles the 14th century urban smithies at Haapsalu, than the 13th–14th century rural smithy of Paatsa, which indicates a convergence of rural and urban smithing traditions by the 14th–15th centuries. Metallographic analysis of iron blooms and bars from the smithy site of Käku provides insight into how the smiths processed bloomery iron and how steel tools were reused.
The non-ferrous metalwork is studied via crucibles and casting moulds. The residue they contained was analysed with a portable spectrometer (pXRF) and a scanning electron microscope (SEM-EDS). The results show that in the 7th to early 13th centuries the casting of silver and tin took place at hill forts and strongholds. Silver residues were detected in 27% of the crucibles, which suggests that silver casting was common. After the crusade, the towns became the main centres for the casting and crafting that previously was undertaken in the fortified centres. Foreign craftsmen introduced imported crucibles that were more durable at high temperatures than crucibles made from local clay. A few of the studied crucibles had residues of pure gold, which indicates a higher level of specialist goldsmithing, compared to the work of pre-crusade craftsmen.https://www.ester.ee/record=b530132
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Early 13th century silver hoard from Kirimäe village, Lääne County: 13. sajandi alguse hõbeaare Kirimäe külast Läänemaalt
No full textEarly 13th century silver hoard from Kirimäe village, Lääne Count
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
An Antiquarian Gift – a Collection of Perm Animal-Style Plaquettes in Estonian History Museum
Full text linkMetDect WP4: Dataset on the chemical composition of non-ferrous artefacts
No full textThis dataset contains information on the chemical composition of archaeological finds (pXRF data) from Estonia, obtained with the SPECTRO xSORT analyser in August 2022. All analysed finds are stored at the Archaeological Research Collection of Tallinn University. The dataset consists of measurements normalised to 100% and is divided into three sections (silver brooches, pewter objects and copper alloy objects). Tuuli Kurisoo and Ragnar Saage presented the results of the analysis "A pilot study of the workshop areas in Estonia" at the 28th EAA Annual Meeting in Budapest, Hungary, in the session "Metals and metalwork in the Borderlands" on 2 September 2022.
Andmekogu sisaldab Eestist leitud arheoloogiliste leidude keemilise koostise analüüsi (pXRF meetodil), mis mõõdeti 2022. aasta augustis kasutades SPECTRO xSORT instrumenti. Kõik analüüsitud leiud pärinevad Tallinna Ülikooli arheoloogia teaduskogust. Andmekogu sisaldab mõõtmise tulemusi, mis on 100%-ni normaliseeritud. Tuuli Kurisoo ja Ragnar Saage esitasid saadud tulemusi suulise ettekandega “A pilot study of the workshop areas in Estonia” 28. Euroopa arheoloogide assotsiatsiooni aastakonverentsil Budapestis, Ungaris, sessioonil session "Metals and metalwork in the Borderlands" 2. septembril 2022
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