Fotogrametrik amaçlı kullanılan tarayıcıların radyometrik ve geometrik doğruluğunun araştırılması
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Dosyalar
Tarih
2002
Yazarlar
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Yayıncı
Selçuk Üniversitesi Fen Bilimleri Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Digital fotogrametri, fotoğrafları digital görüntü dosyalarına çeviren tarama işlemleriyle başlar. Bu çevirme işlemini gerçekleştiren tarayıcılar fotoğraf taşıyıcısından geçen ışığı piksel denen resim elamanlarına çevirirler. Ancak analog verilerden digital veriye geçişte bazı hatalar meydana gelebilir. Bu hatalar ya geometrik bozulma ya da radyometrik olarak ortaya çıkar. Bu nedenle tarayıcıların kaliteleri digital fotogrametri de önemli rol oynar. Bu çalışmada farklı özelliklere sahip çeşitli tarayıcıların test edilmesi ve birbirleriyle kıyaslanması gerçeklendirilmiştir. Öncelikli olarak hava fotoğraflarını tarayan fotogrametrik tarayıcıların hatalarım tespit etmek ve miktarlarım belirlemek hedeflenmiştir. Fotogrametrik üretimde en çok aranan özellik geometrik doğruluk olduğu için öncelikli olarak bu tarayıcıların geometrik doğruluğu incelenmiştir. Daha sonra bu tarayıcıların radyometrik çözünürlük kalitesi, gri tonlarını elde etme kaliteleri ve renk elde etme kaliteleri ayrı ayrı incelenmiştir. Ayrıca fotogrametrik tarayıcıların yarı sıra masaüstü tarayıcılarda bu çalışmaya dahil edilmiş ve yapılan testlerin sonuçlan elde edilmiştir. Geometrik doğruluk testinde elde edilen sonuçlara göre fotogrametrik tarayıcılar için tarama yönünde oluşan hata miktarının tarama yönüne dik doğrultuya (sensör algılama doğrultusuna) göre daha büyük olduğu görülmüştür. Geometrik çözünürlük testinde, 21 yada 28 mikron çözünürlükte taramanın geometrik çözünürlüğe bir etkisi olmadığı görülmüştür.Fotogrametrik tarayıcıların geometrik çözünürlükleri masaüstü tarayıcılara nazaran yüksek doğruluklu olarak elde edilmiştir. Radyometrik doğrulukta, değişik çözünürlüklü tarama yapmanın görüntünün radyometrik doğruluğuna bir etkisi olmadığı tespit edilmiştir. Renk testi için matematiksel olarak öklid mesafesi (AE) hesaplanmış ve elde edilen sonuçlara göre fotogrametrik tarayıcıların renk kalitesinin A4,A3 tarayıcılardan daha zayıf olduğu görülmüştür.
Digital Photogrammetry begins with scanning, which converts a photogrammetric image into a digital image file. Scanners which complies interchanging process, converts transmitted light from the photographic image into the picture elements, called as pixel. Some errors can occure when the analogue data is transmitted to the digital data. This errors appear as either geometric or radiometric deformations. For this reason quality of the scanner have a important role in Digital Photogrammetry. Ill In this study, it was aimed to determined the sources and amountof errors for scanner used in aerial phototos.For this purpose several scanners having different properties were tested and compared to each other. Since, geometric accuracy is the most important properties in the photogrammetric production. The geometric accuracies of the scanners were investigated with presedence. Later, Radiometric resolution quality of the scanners, gray level quality and color quality were searched seperately. On the outher hand, photogrammetric scanners as well as desktop publishing scanner were included into the this study and the results of the test were also presented. According to results obtained from geometric accuracy test, it was seen that the amount of the errors along the scanning directions were appeared to be bigger than perpendicular directions along the scanning, (along the senso directions) In the goemetric resolution test, scanning with the 21 or 28 micron has not have any effects on the geometric resolutionGeometric resolution of photogrammetric scanners was obtained to have more accuracy rather than Desktop Publishing Scanners. In the radiometric accuracy, it was determined that scanning with the different resulotion has not have any effects on the radiometric accuracy of image. For the color test, euclidian distance (AE) was calculated mathematically and according to results obtained from this research.it was seen that the color quality of the photogrammetric scanners was observed to being weaker than the A4, A3, scanners.
Digital Photogrammetry begins with scanning, which converts a photogrammetric image into a digital image file. Scanners which complies interchanging process, converts transmitted light from the photographic image into the picture elements, called as pixel. Some errors can occure when the analogue data is transmitted to the digital data. This errors appear as either geometric or radiometric deformations. For this reason quality of the scanner have a important role in Digital Photogrammetry. Ill In this study, it was aimed to determined the sources and amountof errors for scanner used in aerial phototos.For this purpose several scanners having different properties were tested and compared to each other. Since, geometric accuracy is the most important properties in the photogrammetric production. The geometric accuracies of the scanners were investigated with presedence. Later, Radiometric resolution quality of the scanners, gray level quality and color quality were searched seperately. On the outher hand, photogrammetric scanners as well as desktop publishing scanner were included into the this study and the results of the test were also presented. According to results obtained from geometric accuracy test, it was seen that the amount of the errors along the scanning directions were appeared to be bigger than perpendicular directions along the scanning, (along the senso directions) In the goemetric resolution test, scanning with the 21 or 28 micron has not have any effects on the geometric resolutionGeometric resolution of photogrammetric scanners was obtained to have more accuracy rather than Desktop Publishing Scanners. In the radiometric accuracy, it was determined that scanning with the different resulotion has not have any effects on the radiometric accuracy of image. For the color test, euclidian distance (AE) was calculated mathematically and according to results obtained from this research.it was seen that the color quality of the photogrammetric scanners was observed to being weaker than the A4, A3, scanners.
Açıklama
Anahtar Kelimeler
USAF 1951, NBS1010A Q60, IT8 11, Gray level, MTF, Tarayıcı kalitesi geometrik doğruluk, Radyometrik doğruluk, Geometrik çözünürlük, Digital görüntü, Görüntü kalitesi, Renk uzayı, Gri seviyesi, Renk dönüşümleri, Modülasyon transfer fonksiyonu, Digital image, Image quality, Scanner quality, Geometric accuracy, Color space, Radiometric accuracy, Geometric resolution, Color conversation, Modulatin transfer function
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Künye
Yakar, M. (2002). Fotogrametrik amaçlı kullanılan tarayıcıların radyometrik ve geometrik doğruluğunun araştırılması. Selçuk Üniversitesi, Yayımlanmış doktora tezi, Konya.
