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Yayın Co-registration of surfaces by 3D least squares matching(Amer Soc Photogrammetry, 2010-03) Akça, Mehmet DevrimA method for the automatic co-registration of 3D surfaces is presented. Die method utilizes the mathematical model of Least Squares 2D image matching and extends it for solving the 3D surface matching problem The transformation parameters of the search surfaces are estimated with respect to a template surface. The solution is achieved when the sum of the squares of the 3D Spatial (Euclidean) distances between the surfaces are minimized. The parameter estimation is achieved using the Generalized Gauss-Markov model. Execution level implementation details are given. Apart from the co-registration of the point clouds generated from spacaborne airborne and terrestinal sensors and techniques. the proposed method is also useful for change detection, 3D comparison, and quality assessment tasks Experiments, terrain data examples show file capabilities of the method.Yayın Video çerçeve hız artırımında kapatma yapaylıklarının giderilmesi(IEEE, 2009-06-26) Çizmeci, Burak; Ateş, Hasan FehmiÇerçeve hız arttırımı (ÇHA) yöntemleri, önceleri video standartları arası dönüşümlerde kullanılmış günümüzde ise büyük ekran LCD ve plazma Tv setlerinde daha kaliteli görüntü için sayısal video yayınının zamansal çözünürlüğünün arttırılmasında uygulanmaya başlanmıştır. DSP, FPGA ve ASIC gibi donanımların işlem gücünün artması ÇHA probleminin çözümünde yüksek karmaşıklıkta algoritmaların tasarlanmasına olanak sağlamıştır.Bu bildiride çok aşamalı devinim vektör (DV) iyileştirilmesi art işlemleri ve kapanma/açılma bölgelerine uyarlamalı örtüşmeli blok devinim denkleştirmesi yöntemleri ile uzamsal ve zamansal düzlemde tutarlı bir ÇHA algoritması önermekteyiz. Hekzagonal devinim kestirim (DK) algoritmasının verdiği düşük güvenirlikli DV'leri çok aşamalı iyileştirme art-işlemlerine tabi tutulur. Uzamsal olarak tutarlı bir DV alanı elde edildikten sonra komşu vektörler arasındaki ilişkiler ve ardışık 4 çerçevenin DV bilgisi kullanılarak kapanma/açılma bölgeleri tespit edilir.Örtüşmeli blok devinim denkleştirme filtresi (ÖBDD) tespit edilen bu bölgelelere uyarlanarak kapanma/açılmadan kaynaklanan yapaylıkların azaltılması sağlanır. Böylece var olan ÇHA yöntemlerine göre uzamsal çözünürlükten daha az ödün verilerek ve daha az yapaylıkla ÇHA gerçekleştirilmektedir.Yayın 3-Dimensional pre- and post-fire comparison of forest areas(International Society for Photogrammetry and Remote Sensing, 2018-03-06) Akça, Mehmet Devrim; Stylianidis, Efstratios; Poli, Daniela; Gruen, Armin W.; Altan, Mehmet Orhan; Hofer, Martin; Smagas, Konstantinos; Martin, Victor Sanchez; Garcia, Alejandro; Jimeno, Elisa; Walli, AndreasForest agencies give special attention to forest fires where post-disaster loss can rarely be gauged in a quick and economic way unless an appropriate technology is adopted. Determination of the planimetric and volumetric changes between pre- and post-fire is in high demand. The FORSAT system (a satellite processing platform for high resolution forest assessment) was developed to meet the relevant demands. It has the capability of extracting of 3D geometric information from the very-high resolution (VHR) imagery from satellite optical sensors and automatic 3D change detection. FORSAT includes two main units. The first one is dedicated to the geometric and radiometric processing of satellite optical imagery and 2D/3D information extraction. This includes: image radiometric pre-processing, image and ground point measurement, improvement of geometric sensor orientation, quasi-epipolar image generation for stereo measurements, digital surface model (DSM) extraction by using a precise and robust image matching approach specially designed for VHR satellite imagery, generation of orthoimages, and 3D measurements in single images using mono-plotting and in stereo images. FORSAT supports most of the VHR optically imagery commonly used for civil applications: IKONOS, OrbView - 3, SPOT - 5 HRS, SPOT - 5 HRG, QuickBird, GeoEye-1, WorldView-1/2, Pléiades 1A/1B, SPOT 6/7. The second unit of FORSAT is dedicated to 3D surface comparison for change detection. It allows users to import DSMs, to co-register them using an advanced 3D surface matching approach and to calculate the planimetric and volumetric changes between epochs. The capacity and benefits of FORSAT have been tested in two real cases, where are burned areas located in Cyprus and Austria. The geometric characteristics of burned forest areas have been identified both in 2D plane and 3D volume dimensions, using pre- and post-fire optical data from different sensors. FORSAT is a single source and flexible forest information solution, allowing expert and non-expert remote sensing users to monitor forests in three and four dimensions from VHR optical imagery for many forest information needs.Yayın FORSAT: a 3D forest monitoring system for cover mapping and volumetric 3D change detection(Taylor and Francis Ltd., 2020-08-02) Stylianidis, Efstratios; Akça, Mehmet Devrim; Poli, Daniela; Hofer, Martin; Gruen, Armin W.; Sánchez Martín, Víctor; Smagas, Konstantinos; Walli, Andreas; Altan, Mehmet Orhan; Jimeno, Elisa; Garcia, AlejandroA 3D forest monitoring system, called FORSAT (a satellite very high resolution image processing platform for forest assessment), was developed for the extraction of 3D geometric forest information from very high resolution (VHR) satellite imagery and the automatic 3D change detection. FORSAT is composed of two complementary tasks: (1) the geometric and radiometric processing of satellite optical imagery and digital surface model (DSM) reconstruction by using a precise and robust image matching approach specially designed for VHR satellite imagery, (2) 3D surface comparison for change detection. It allows the users to import DSMs, align them using an advanced 3D surface matching approach and calculate the 3D differences and volume changes (together with precision values) between epochs. FORSAT is a single source and flexible forest information solution, allowing expert and non-expert remote sensing users to monitor forests in three and four (time) dimensions. The geometric resolution and thematic content of VHR optical imagery are sufficient for many forest information needs such as deforestation, clear-cut and fire severity mapping. The capacity and benefits of FORSAT, as a forest information system contributing to the sustainable forest management, have been tested and validated in case studies located in Austria, Switzerland and Spain.
