XXII ISPRS Congress 2012: Technical Commission VII

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Multivolume work

Persistent identifier:: 1663813779

Title:: XXII ISPRS Congress 2012

Sub title:: Melbourne, Australia, 25 August-1 September 2012

Year of publication:: 2013

Place of publication:: Red Hook, NY

Publisher of the original:: Curran Associates, Inc.

Identifier (digital):: 1663813779

Language:: English

Additional Notes:: Kongress-Thema: Imaging a sustainable future

Corporations:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Adapter:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Founder of work:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Other corporate:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Document type:: Multivolume work

Volume

Persistent identifier:: 1663821976

Title:: Technical Commission VII

Scope:: 546 Seiten

Year of publication:: 2013

Place of publication:: Red Hook, NY

Publisher of the original:: Curran Associates, Inc.

Identifier (digital):: 1663821976

Illustration:: Illustrationen, Diagramme

Signature of the source:: ZS 312(39,B7)

Language:: English

Additional Notes:: Erscheinungsdatum des Originals ist ermittelt.; Literaturangaben

Usage licence:: Attribution 4.0 International (CC BY 4.0)

Corporations:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Adapter:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Founder of work:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Other corporate:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Publisher of the digital copy:: Technische Informationsbibliothek Hannover

Place of publication of the digital copy:: Hannover

Year of publication of the original:: 2019

Document type:: Volume

Collection:: Earth sciences

Chapter

Title:: [VII/7, III/2, V/1, V/3, ICWG V/I: LOW-COST UAVS (UVSS) AND MOBILE MAPPING SYSTEMS]

Document type:: Multivolume work

Structure type:: Chapter

Chapter

Title:: AUTOMATIC EXTERIOR ORIENTATION PROCEDURE FOR LOW-COST UAV PHOTOGRAMMETRY USING VIDEO IMAGE TRACKING TECHNIQUE AND GPS INFORMATION T. Anai, T. Sasaki, K. Osaragi, M. Yamada, F. Otomo, H. Otani

Document type:: Multivolume work

Structure type:: Chapter

cedure r orientation planning and pilot control GmbH. High during flight, are obtained ocessing, the solution still video image oint tracking acking result nate on high matching of ; of this sub- ass points. In r orientation The result of of candidate jn and scale. e positioning itrol points is st regression. ed based on delling from lon tation ure point and Code” (OC) f OC image nstead of the ization of the st pixel. The a ed tan AR y ; Al |+|A | > (1) se if |ar|+|ar,|27 Cy = 2x ; === otherwise AO In this equation, 4/, and AZ, show horizontal and vertical gradient of pixel (x, y). N is the quantization level of direction. N is set to 16 typically (Figure 3). The “y” is the threshold value for the suppressing of small gradient pixel. % iue s Ford i 3x Figure 3. Orientation Code (N = 16) In order to extract common feature points from OC image, we use Orientation Code Richness (OCR) that extracts the pixels which have high entropy of OC. The entropy of the local limited area of the pixel size M-by-M region at the interest pixel (x, y) is calculated as follows, P.) die /M*—h,(N) i E, =) P,(i)log, P,(i) i=0 Where h,,(i) (i =0,1,,,,,,N-1) means frequency of OC of M-by-M pixel size region. When each OC goes with uniform distribution P,,(i)- 1/N, the maximum value of entropy £,,. is log;N. Consequently, the richness R,, is defined as E um if E,2«,E 3 pay o ob m IS E R,, = E x = OE, x y e" max ( ) 0 otherwise Where, the threshold value a, is defined to remove low entropy area. The matching process using OC image (OCM) is similar to other simple image based template matching. The difference between a template image patch from OC image (Ot) and search OC image (Oi) is defined as following equation, =-L 40,0) M M Zo) min{a—&|, N —|a— 4} if a#N,b#zN (4) N/4 otherwise where D - difference between O, and Oj M = Size of template image patch d = difference between a pixel and b pixel International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B7, 2012 XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia Figure 4 shows the example of OC image. From this image, it is understood that the OC image is independent from the changing brightness and also OC image describe the important feature of image. Figure 5 shows the result of OCR. The bright pixel on OCR means the high entropy of OC. Figure 6 shows the example of OCM. From the robustness of OCM, almost points are not influenced by the changing of brightness or noise of image. 8 E a)Original Image (8bit Gray Scale) segs b) OC Image Figure 4. Example of OC image Figure 5. Example of OCR

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