Orientador: Antonio Maria Garcia Tommaselli / Resumo: Com a disponibilidade de câmaras digitais, dados de posicionamento por satélites (GPS) e sistemas inerciais (INS), tornaram-se possíveis novas aplicações que envolvem a obtenção de produtos cartográficos em quase tempo real (após o processamento dos dados coletados em vôo), como o monitoramento de desastres ambientais. Tais aplicações necessitam de informações georreferenciadas com características de rapidez e confiabilidade, que podem ser obtidas pela técnica fotogramétrica digital, apoiada pelos sensores que fornecem a orientação direta da câmara. Em geral, os parâmetros fornecidos pelos sensores de orientação utilizados para mapeamento não possuem a acurácia necessária para eliminar totalmente a paralaxe vertical do modelo e, por conseguinte, a visualização estereoscópica da cena fica prejudicada. Para resolver este problema, propôs-se uma metodologia que é baseada na compatibilização dos parâmetros de orientação direta (GPS + INS), mediante um modelo de coplanaridade modificado, num ajustamento pelo método dos Mínimos Quadrados. Os valores observados correspondem a pontos homólogos medidos automaticamente no modelo por técnicas de correlação por área. Após o refinamento dos parâmetros de orientação exterior (OE), as imagens são normalizadas por meio de uma reamostragem epipolar, com intuito de proporcionar uma melhor visualização estereoscópica da cena e auxiliar o processo de geração automática de Modelos Digitais de Terreno. Neste sentido, módulos computacionais foram desenvolvidos em linguagem C++ para a geração totalmente automática de estereomodelos em quase tempo real. Experimentos com dados simulados e reais foram conduzidos, na ordem de verificar a eficácia da metodologia com respeito a eliminação da paralaxe vertical do modelo e a acurácia das coordenadas no espaço objeto calculadas por intersecção...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: With the availability of digital cameras, satellite positioning systems (GPS) and inertial navigation systems (INS), new applications such as fast cartography and real time environmental monitoring became feasible. Such applications require georeferenced information with characteristics of speed and reliability that can be obtained by digital photogrammetry, using additional data from sensors of direct orientation. Generally, the parameters supplied by the sensors are under the required accuracy to elimine the vertical parallax in the model. To solve this problem, the methodology proposed in this project is based on the reprocessing of the parameters of orientation supplied by the sensors, using a modified coplanarity model. The observations are the images coordinates automatically measured in each image using an area-based correspondence method. After the EO parameters refinement, using the modified coplanarity model, the images are normalized through an epipolar resampling, in order to provide a confortable stereoscopic visualization of the model, since vertical parallax is eliminated, and to facilitate the process of automatic Digital Terrain Model generation. In order to test the proposed approach, computational programs were developed in C++ language, enabling the full automatic generation of estereomodelos in almost real time. Experiments with simulated and real data were performed, in order to verify the performance of the method with respect to y-parallax elimination and accuracy of reconstructed object space coordinates. These experiments are presented and discussed showing the effectiveness of the proposed approach for automatic generation of stereo models. / Mestre

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Esta dissertação apresenta um aperfeiçoamento para o Sistema de Imagens Tridimensional Híbrido (SITH) que é utilizado para obtenção de uma superfície tridimensional do relevo de uma determinada região a partir de dois aerofotogramas consecutivos da mesma. A fotogrametria é a ciência e tecnologia utilizada para obter informações confiáveis a partir de imagens adquiridas por sensores. O aperfeiçoamento do SITH consistirá na automatização da obtenção dos pontos através da técnica de Transformada de Características Invariantes a Escala (SIFT - Scale Invariant Feature Transform) dos pares de imagens estereoscópicas obtidos por câmeras aéreas métricas, e na utilização de técnicas de interpolação por splines cúbicos para suavização das superfícies tridimensionais obtidas pelo mesmo, proporcionando uma visualização mais clara dos detalhes da área estudada e auxiliando em prevenções contra deslizamentos em locais de risco a partir de um planejamento urbano adequado. Os resultados computacionais mostram que a incorporação destes métodos ao programa SITH apresentaram bons resultados. / This dissertation presents an improvement of the Three-Dimensional Hybrid Imaging System (SITH) that is used to obtain a three dimensional surface relief of a particular region from the same two consecutive air frames it. Photogrammetry is the science and technology used to obtain reliable information from images acquired by sensors. Improving the automation of the SITH will consist of points obtained using the technique of Invariant Feature Transform Scale (SIFT - Scale Invariant Feature Transform) pair of stereoscopic images obtained by aerial metric cameras, and the use of means of cubic spline interpolation for smooth surfaces produced by the same three-dimensional, providing a clearer view of the details of the study area and aiding in effective prevention against landslides in hazardous locations from an urban planning appropriate. The computational results show that the incorporation of these methods to the program SITH had good results.

A boa postura corporal é importante para otimizar a função vocal. Apesar de encontrado o assunto postura e voz na literatura, não foram encontradas pesquisas que estudem os posicionamentos específicos de cabeça e pescoço e como estas influenciam o sinal de voz. O objetivo do presente estudo foi verificar a influência da anteriorização, da posteriorização e da extensão da cabeça no sinal de voz. Foram selecionados 50 homens e 50 mulheres não tabagistas e sem queixas vocais, com idade média de 24,72 e 23,46 anos, respectivamente. Foram demarcados nos participantes três pontos anatômicos: acrômio da escápula, côndilo da mandíbula e processo xifoide do esterno. Os indivíduos foram fotografados sentados em vista lateral com a coluna vertebral ereta simultaneamente ao processo de gravação da vogal /a/ sustentada pelo programa Sound Forge 7.0® em quatro diferentes posturas cervicais: P1) ereta; P2) anteriorização de cabeça; P3) posteriorização de cabeça; e P4) extensão cervical. As posturas foram analisadas por fotogrametria computadorizada pelo programa Corel Draw X3®. As vozes foram estudadas por análise acústica por meio do programa MDVP e por avaliação perceptivo auditiva realizada por três fonoaudiólogos meio de uma escala visual analógica com 100 milímetros de comprimento. A partir dos pontos anatômicos demarcados foram estudados pela fotogrametria os ângulos: côndilo-acrômio (ACA), mento-esternal (AME) e de Frankfurt (AF). Os resultados posturais e vocais foram analisados estatisticamente pelos testes Anova e Tukey com p<0,05. Na fotogrametria, foram encontradas diferenças significantes (p<0,05) em ACA e AME na P2 e P3 em relação à P1 e em AF na P4 quando comparado à P1, para homens e mulheres. Na análise acústica da voz foram encontradas diferenças significantes (p<0,05) na frequência fundamental (F0) na comparação da P2 e P4 em relação à P1 em ambos os grupos, e no shimmer na P4 no grupo das mulheres. Na avaliação perceptivo auditiva foram encontradas diferenças significantes (p<0,05) na comparação da P2 com P1 com pior grau geral, maior tensão e pitch mais agudo para ambos os grupos e maior rugosidade no grupo dos homens na P2. Foi observado na comparação da P3 com P1 diferenças significativas (p<0,05) com pior grau geral, maior tensão, aumento do loudness, pitch mais agudo e maior rugosidade para ambos os grupos na P3. E na P4 foram encontradas pior grau geral, maior tensão, aumento do loudness e pitch mais agudo para ambos os grupos em relação à P1 (p<0,05), e maior rugosidade e soprosidade na P4 (p<0,05) para o grupo dos homens. Conclui-se que pelos achados fotogramétricos que os indivíduos se posicionaram corretamente nas posturas solicitadas. Nas posições da P2, P3 e P4 a voz se torna mais aguda, com maior tensão e com pior qualidade vocal quando comparadas à P1, e em P3 e P4 também se observa o aumento do loudness. / The good corporal posture is important to optimize the vocal function. Although the subject posture and voice has been found in the literature, it wasnt found researches that investigates how the specifics positions of head and neck influence the vocal signal. The aim of the present investigation was to verify the influence of forward head position, backward head position and cervical extension in the vocal signal. It was selected 50 men and 50 women, nonsmokers and without vocal complains, with average age of 24,72 and 23,46 years old, respectively. It was marked in the subjects three anatomic structures: acromion in the scapula, mandibular condyle and xiphoid process in the sternum. The participants were photographed sited in lateral view in a straight spine alignment simultaneously of the recording process of the sustained vowel /a/ by the program Sound Forge 7.0® in four different cervical postures: P1) straight alignment; P2) forward head position; P3) backward head position; and P4) cervical extension. The postures were analyzed by photogrammetry by the Corel Draw program. The voice were studied by acoustic analysis by the MDVP program and by perceptual speech analysis done by three speech therapists using a visual analogue scale with 100 millimeters of length. From the anatomic structures marked were studied by photogrammetry the angles: condyle-acromion (ACA), menton-sternum (AME) and Frankfurt (AF). The postural and vocal results were statistically analyzed by the Anova and Tukey tests with p<0,05. In the photogrammetry, were found significant differences (p<0,05) in ACA and AME in P2 and P3 in relation to P1 and in AF in P4 when compared to P1, for both men and women. IN the acoustic analysis were found significant differences (p<0,05) in fundamental frequency (F0) in the comparison of P2 and P4 with P1 in both groups, and in shimmer in the P4 for the women group. In the perceptual speech analysis were found significant differences (p<0,05) ) in the comparison of P2 with P1 with worse general degree, increased tension and pitch more acute for both groups and increased roughness for the men group in the P2. It was observed in the comparison of P3 with P1 significant differences (p<0,05) with worse general degree, increased tension, increased loudness, pitch more acute and increased roughness for both groups in P3. And in P4 were found worse general degree, increased tension, increased loudness and pitch more acute for both groups and increased roughness and breathiness in P4 (p<0,05) for the men group. It can be concluded by the founds in photogrammetry that the subjects were correctly positioned in the postures solicited. IN the P2, P3 and P4 positions the voice become more acute, with more tension and worse quality when compared to the P1 position, and also in P3 and P4 can be observed increased loudness.

Durante a infância e a adolescência, ocorrem várias mudanças posturais, em função dos ajustes necessários para a estruturação e definição da postura. A postura sofre mudanças por causa da influência hormonal que ocorre com o início da puberdade e com o crescimento musculoesquelético. Sendo assim, as fases pré puberal e puberal, são cruciais para o desenvolvimento de uma boa postura. Além disso, alterações de sobrecarga durante esta fase, podem interferi no desempenho do aparelho locomotor. Dentre os fatores, que influenciam essas variáveis, está o uso dos calçados de salto alto que vêm se tornando cada vez mais precoce e freqüente nesta população. O objetivo, deste estudo foi avaliar a influência dos calçados de salto alto na postura e na marcha de adolescentes ente 13 a 20 de idade. Foi realizado com adolescentes do sexo feminino, para o estudo postural e impressão plantar avaliadamos 50 adolescentes do grupo não usuárias (GNU) de calçados de salto alto e 50 do grupo usuárias (GU). O estudo postural foi feito por fotografias nas condições descalça e com salto anabella e analisadas pelo software SAPO. Os ângulos medidos foram: lordose lombar, alinhamento horizontal da pelve, ângulo do joelho, ângulo tíbio társico, ângulo frontal do membro inferior direito (D) e esquerdo (E), ângulo Q (D) e (E) e ângulo do retropé (D) e (E). Através da impressão plantar analisamos o Índice de Chippaux-Smirak. O estudo da marcha foi realizado com 11 adolescentes no GNU e 9 do GU. Através da plataforma de força analisamos a força reação do solo nas condições descalça e com o salto. Os dados foram submetidos a análises descritivas. Foi adotado um nível de significância de 5%. Na comparação entre as condições, encontramos com o uso do salto no GNU: retificação lombar, retroversão pélvica, aumento do ângulo tíbio-társico, aumento do valgo de joelhos e patelar e varo de retropé. Já para GU, encontramos as mesmas modificações que no GNU, porém com variações diferentes e com exceção apenas para o ângulo lombar que apresentou hiperlordose e ângulo pélvico com anterversão. Na comparação entre os grupos, observamos na condição descalça que o GU apresentou menor ângulo da lordose lombar, maior anteversão, menor ângulo tíbio társico, maior valgismo de joelho e patela. Já na condição com o salto o GU apresentou o ângulo de lordose lombar menor, ângulo pélvico com postura inversa ao do GNU, acentuação do valgismo patelar que manteve os grupos diferentes e embora ambos tenham apresentado varo de retropé, o GU mostrou um valor maior. O arco longitudinal se mostrou diferente com valores menores para o GU e classificadas com pés normais enquanto que o GNU foi classificado com pés intermediários. Na marcha, o tempo de apoio total e menor força vertical na comparação entre os dois grupos se apresentaram menor para GU nas duas condições. A taxa de crescimento do segundo pico foi maior na condição descalça para GU e a taxa de crescimento do pico passivo foi maior na condição descalça em ambos os grupos. A variável pico passivo apresentou-se em ambos os grupos nas duas condições. Concluímos que o calçado de salto rígido influenciou de forma significante os ângulos posturais, tanto na observação aguda no GNU, como na observação de uso crônico como no GU, assim como, observado no arco plantar e em algumas variáveis da força reação do solo vertical. / During childhood and adolescence, there are several posture changes depending on the settings necessary for the structuring and definition of posture. The posture change because of the hormonal influence that occurs with the onset of puberty and the musculoskeletal growth. Thus, the pre pubertal and pubertal stages are crucial for the development of good posture. Moreover, changes of overload during this phase, may interfere with the performance of the locomotor system. Among the factors that influence these variables, is the use of high-heeled shoes that are becoming increasingly early and frequent in this population. The objective of this study was to evaluate the influence of high-heeled shoes in posture and pace of adolescents between 13 to 20 of age. Was conducted with female adolescents in the study posture and printing plant of the group evaluated 50 adolescents not using (GNU) of high-heeled shoes and 50 of the group users (GU). The study was done by photos at the postural conditions barefoot and Anabella heeland analyzed by software SAPO. The angles were measured: lumbar lordosis, horizontal alignment of the pelvis, knee angle, tepid-tarsus angle, frontal angle of the right lower limb (D) and left (E), angle Q (D) and (E) and angle of the hindfoot ( D) and (E). By printing plant we analyzed the index of Chippaux-Smirak. The study of the march was conducted with 11 adolescents in the GNU and 9 of GU. Through the platform of force to analyze the ground reaction force in accordance with the barefoot and with the heel. The data were submitted to descriptive analysis. Was adopted a significance level of 5%. In the comparison between conditions, we find with the heel using in the GNU: lumbar adjustment, pelvic retroversion, increase of the tepid-tarsus angle, increase in the valgus knees and patellar varus and hindfoot of. For GU, we find the same changes as in GNU, but with different variations and except only for the lumbar angle that showed hyperlordosis and pelvic angle with anterversion. In the comparison between groups, we observed in the barefoot condition that the GU had smaller angle of lumbar lordosis, increased anteversion, lower tepid-tarsus angle, more the knee and patella valgus. Already provided with the heel, GU had a lower lumbar lordosis angle, pelvic angle with the inverse posture of the GNU, stress of the patellar valgus that kept the difference between the groups and although both have made the hindfoot varus, the GU has a higher value. The longitudinal arch was different with lower values for the GU and classified with normal feet while GNU was classified with intermediaries feet. In pace, the time of support and lower total vertical force in the comparison between the two groups presented lower for GU in the two conditions. The growth rate of the second peak was higher in the barefoot condition for GU and the growth rate peak was higher in the passive condition barefoot in both groups. The variable peak liabilities is presented in both groups in both conditions. We conclude that the footwear heel hard to significantly influence the postural angles, both in acute observation in GNU, and the observation of chronic use as in GU, as well as observed in the plantar arch and some variables of the vertical ground reaction force.

O propósito deste trabalho foi verificar a reprodutibilidade bem como a repetibilidade do método de avaliação postural por meio da fotogrametria computadorizada. Para isto 21 indivíduos, com idade 24,2 ± 1,3 anos de idade, foram fotografados em posição anterior, posterior, perfil e face. Para realização destas fotografias foram demarcados sobre a pele pontos anatômicos que são normalmente utilizados na avaliação postural tradicional. A partir destes pontos foram analisados diferentes ângulos através do aplicativo ALCimagem-2000. Para a análise interexaminador as fotos foram avaliadas por três examinadores diferentes e os resultados comparados. Para a análise intraexaminador as mesmas fotos foram avaliadas pelo mesmo examinador em duas ocasiões diferentes com um mês de intervalo. Para a análise da repetibilidade do método os voluntários foram fotografados duas vezes com intervalo de uma semana e as fotos avaliadas pelo mesmo examinador. Para comparação dos resultados intra e interexaminadores foram aplicados o coeficiente de correlação intraclasse. Os resultados revelaram que o método proposto apresenta significativa confiabilidade interexaminadores. Dos ângulos estatisticamente confiáveis, alguns tiveram menor coeficiente de confiabilidade, principalmente os ângulos do plano sagital referentes às curvaturas vertebrais, como lordose cervical, cifose torácica e lordose lombar. Na avaliação intra-examinador só não apresentou confiabilidade o ângulo da cifose torácica. Na repetibilidade do método somente o ângulo inferior da escápula não apresentou confiabilidade. Portanto, a fotogrametria computadorizada sugere ser um método confiável para avaliação postural no plano frontal anterior e posterior. Porém, para a análise no plano sagital necessita de mais estudos para definir parâmetros de normalidade das curvaturas vertebrais. / The purpose of this work was to verify the reproducibility, as well as the method repeatibility for postural evaluation through photogrammetry. For that, 21 individuals being 24,2 ??1,3 years old were photographed in anterior, posterior, profile and face positions. To perform these photos, several anatomic sites, which are often used in the traditional postural evaluation, were marked on the skin. Different angles from these sites were examined through the program ALCimagem-2000. For the inter-examiner analysis, the photos were evaluated by three different examiners whose results were compared. For the intra-examiner analysis, the same photos were evaluated by the same examiner in two different occasions. For the analysis of the repeatibility of the method, the volunteers were photographed twice with a period of a week interval, and the photos were evaluated by the same examiner. For comparing inter and intraexaminer results, the intra-class correlation coefficient was applied. The results revealed that the proposed method presented good inter-examiner reliability. From the statistically reliable angles, some had a lesser reliability coefficient, mainly the sagital plane angles referring to vertebral flexures such as the cervical lordosis, thoracic kyphosis, and lumbar lordosis. In the intra-examiner evaluation, just the thoracic kyphosis angle hasn\'t presented reliability. As for the repeatibility of the method just the inferior scapular angle haven\'t presented reliability. Thus, computerized photogrammetry seem be a reliable method for postural evaluation on the frontal, anterior and posterior planes. However, the sagital plane needs more studies to define normality parameters for the vertebral flexures.

This thesis suggests a modification to the popular Scale Invariant Feature Transform (SIFT) algorithm (Lowe, 2004) often used in photogrammetry and computer vision to find features in images for measurement. The SIFT algorithm works by first detecting points in images at different scales and sizes. It then refines the position of the found points. The algorithm creates a descriptor of the point based on the region around the point. Finally the points can be matched against other points in different images using the descriptor. The suggested modification is built upon a paper by Förstner and Gülch (1987) where a method for performing a subwindow localization is presented. In this thesis the keypoints detected by the SIFT algorithm are modified on the subwindow level in order to improve the robustness with respect to the selected window position. Several different methods of tweaking the suggested modification and the SIFT algorithm were tested. The methods were evaluated on two different test cases. The first used a camera calibration software to compare accuracy of keypoints by looking at the residuals of the calibration. The other test involved creating a point cloud of images of a planar surface, evaluating the results by looking at the standard deviation in keypointoffset from the plane.The results show that neither test gave evidence that the proposed modification was an improvement. It was found that the algorithm had problems with oblique projections of circles, i.e. ellipses. Therefore there is potentialto use homography in special cases to circumvent this problem and get better precision. Furthermore tests involving more lines and intersections in the test images should be performed before this suggested modificationcan be completely discarded.

A influência das alterações posturais na produção da voz é um assunto bastante interessante e de grande importância para aqueles que utilizam a voz profissionalmente. O objetivo do presente estudo é identificar a influência no sinal vocal de um mesmo indivíduo quando este muda sua postura corporal. Foram realizadas as análises de 25 amostras vocais de um indivíduo que emitiu a vogal sustentada /a/ em três diferentes posturas corporais: A) ortostática natural do sujeito; B) anteriorização da cabeça associada com extensão da coluna cervical; e C) aumento da cifose torácica associada com anteriorização de cabeça. O indivíduo foi fotografado simultaneamente ao processo de gravação da voz. As posturas foram avaliadas por fotogrametria pelo programa Corel Draw 10. A voz foi analisada por análise acústica por meio do programa MDVP inserido no software Multi Speech 3700 da Kay Elemetric Corporation e pela avaliação perceptivo-auditiva da voz. O resultado comparativo entre as amostras vocais nas posturas A e B foi significante, na análise acústica, na variável e jitter (%); e na avaliação perceptivo-auditiva, as diferenças observadas foram referentes à qualidade vocal, à ressonância e ao pitch, que se tornou mais agudo em 56% das amostras. Na comparação das posturas A e C, não houve resultado significativo na análise acústica; e na avaliação perceptivo-auditiva as mudanças percebidas foram referentes à qualidade vocal, à ressonância e ao pitch, que se tornou mais agudo em 60% das amostras. Conclusão: as diferenças observadas na comparação das posturas A e B foram: aumento do valor médio de jitter; aumento do pitch; ressonância se tornou posterior e abafada; e piora na qualidade vocal. As diferenças observadas na comparação das posturas A e C foram: aumento do pitch; ressonância se tornou comprimida; e piora na qualidade vocal. / The influence of the different corporal postures in the voice production is a very interesting subject and it\'s very important for those who use their voice professionally. The aim of the present investigation is to identify the influence in the voice signal of the same subject whenever he changes his corporal posture. It was made the analysis of 25 vocal samples of one subject who emitted the vocal sustained /a/ in three different corporal postures: A) normal alignment of the subject; B) cervical spine extension associated with forward head position; and C) increased thoracic kyphosis associated with forward head position. The subject was photographed simultaneously of the recording process. The postures were evaluated by photogrammetry by the Corel Draw 10 program. The voice was analyzed by acoustic analysis by the MDVP program inserted in the Multi Speech 3700 software from Kay Elemetric Corporation and by perceptual speech analysis. The comparative result between the voices samples in the postures A and B was significant, to the acoustic analysis, to the variable jitter (%); and to the perceptual speech analysis, the differences observed were related to vocal quality, resonance and pitch, which turned out to be more acute in 56% of the samples. In the comparison of the postures A and C, there wasn\'t significant result in the acoustic analysis; and to the perceptual speech analysis the changes noticed were related to vocal quality, resonance and pitch, which turned out to be more acute in 60% of the samples. Conclusion: the differences observed on the comparison of the postures A and B were: jitter medium value increased; pitch increased; resonance turned out to be posterior and muffled; and worse voice quality. The differences observed on the comparison of the postures A and C were: pitch increased; resonance turned out to be compressed; and worse voice quality.

There has been a marked increase in melt season length over the past two decades on glaciers and ice caps within Canada’s Queen Elizabeth Islands (QEI). Prior to the year ~2000 land ice was in a state of slightly negative mass balance (-11 +/- 11.5 Gt yr⁻¹ over 1958-1995), but recent GRACE measurements suggest that mass losses averaged -33 +/- 5 Gt yr⁻¹ between 2003-2015. These losses have primarily been attributed to meltwater runoff, making the QEI one of the largest recent contributors to sea level rise outside of the ice sheets. Despite these losses, there is a lack of information concerning how a warming climate is affecting small (<1 km²) ice bodies, which are considered sensitive indicators of change due to their short response time. In this study, historical and contemporary aerial photographs, high resolution optical satellite imagery, and ground penetrating radar (GPR) surveys are used to determine area, thickness, mass and volume changes of Adams Icefield within Expedition Fiord, Axel Heiberg Island, Nunavut, over the past seven decades (1948/59-2019). Area changes are determined from a comparison of air photos acquired in 1948/59 with satellite images acquired since 1979. Contemporary (2001, 2012, 2019) digital elevation models (DEMs) were either collected or created from stereo satellite images, and via aerial photo surveys using Structure from Motion photogrammetry. DEM of Difference maps calculated from these DEMs provide volume and mass changes. Results illustrate a steady reduction in glacier area, thickness, and volume prior to the year ~2000, followed by a rapid increase in losses over the past two decades. As a result, Adams Icefield is now rapidly declining and is likely to completely disappear early in the twenty-second century.

During the past three years, a research project has been carried out in the Department of Mechanical Engineering at UCT, directed at developing a system to accurately reproduce three-dimensional (3D), sculptured surfaces on a three axis computer numerically controlled (CNC) milling machine. Sculptured surfaces are surfaces that cannot easily be represented mathematically. The project was divided into two parts: the development of an automatic noncontact 3D measuring system, and the development of a milling system capable of machining 30 sculptured surfaces (Back, 1988). The immediate need for such a system exists for the manufacture of medical prostheses. The writer undertook to investigate the measurement system, .with the objective to develop a non-contact measuring system that can be used to 'map' a sculptured surface so that it can be represented by a set of XYZ coordinates in the form required by the milling system developed by Back (1988). This thesis describes the development of a PC-based near-realtime photogrammetry system (PHOENICS) for surf ace capture. The topic is introduced by describing photogrammetric principles as used for non-contact measurements of objects. A number of different algorithms for image target detection, centering and matching is investigated. The approach to image matching adopted was the projection of a regular grid onto the surface with subsequent matching of conjugate grid intersections. A general algorithm which automatically detects crosses on a line and finds their accurate centres was developed. This algorithm was then extended from finding the crosses on a line, to finding all the intersection points of a grid. The algorithms were programmed in TRUE BASIC and specifically adapted for use with PHOENICS as an object point matching tool. The non-contact surface measuring technique which was developed was used in conjunction with the milling system developed by Back (1988) to replicate a test object. This test proved that the combined system is suitable for the manufacture of sculptured surf aces. The accuracy requirements for the manufacture of medical prostheses can be achieved with the combined measuring and milling system. At an object-to-camera distance of 0.5 m, points on a surface can be measured with an accuracy of approximately 0.3 mm at an interval of 5 mm. This corresponds to a relative accuracy of 1:1600. Back (1988) reported an average undercutting error of 0.46 mm for the milling system. This combines to an uncertainty of 0.55 mm. Finally, the limitations of PHOENICS at its prototype stage as a surface measuring tool are discussed, in particular the factors influencing the system's accuracy. PHOENICS is an ongoing project and the thesis is concluded by some recommendations for further research work.

The goal of this diploma thesis is to automate photogrammetric measuring system TRITOP. In the literature retrieval part there is a review of digitizing methods and its description. Further it contains a description of the photogrammetric system TRITOP role. The practical part of the thesis deals with methodology of the TRITOP measurement and evaluation process automation. Automation is then verified on a practical example.