FACULTY OF GEODESY AND CARTOGRAPHY W A R S A W U N I V E R S I T Y O F T E C H N O L O G Y Quality assessment of DIM on oblique images (preliminary results) Wojciech Ostrowski, Krzysztof Bakuła, Zdzisław Kurczyński Warsaw University of Technology, Faculty of Geodesy and Cartography EUROSDR/ISPRS WORKSHOP ON 'OBLIQUE CAMERAS AND DENSE IMAGE MATCHING' 19-0 October 015
Oblique images in Poland Cities: Białystok, 7 cm, X 014 Lublin, 5 cm, X 014 Poznań, 4cm, VII 013 Gliwice, 8 cm, IV 013 Katowice, 8 cm, V 014 Łódź, 6 cm, XI 01 Kielce, 9 cm, IX 011
Camera IGI DigiCAMs Five cameras in maltan cross configuration Three 39 Mpixels (forward, backward, nadir) Two 50 Mpixels (sides)
Test fields Poznań GSD 4.5 cm (in center of forward/backward images) GSD 4.0 cm (in center of side looking images) 816 oblique images (04 each direction) 60% forward overlap 40% side overlap
Test fields Łódź GSD 6.0 cm (in center of forward/backward images) GSD 5.5 cm (in center of side looking images) 8000 oblique images (approx. 000 each direction) 55% forward overlap 30% side overlap
Test fields Katowice GSD 8.0 cm (in center of forward/backward images) GSD 7.0 cm (in center of side looking images) 16 oblique images (54 each direction) 65% forward overlap 35% side overlap
Reference dataset Terrestrial laser scanning Point denisty above 1 cm Cloud to cloud registration with subcentimeter accuracy Four reference dataset for each city Łodź and Poznań were measured with Topcon GLS- 000 (courtesy of TPI, Topcon Reseller) Katowice with Z+F 5006h
Workflow Calibrated camera Orientation in Inpho Match-AT Undistorted images Matching (Fix EO and IO) Agisoft PhotoScan Pix4D nframes SURE
Poznań side looking GSD ~4 cm Double overlap Point cloud from SURE
Poznań side looking DSM difference + 0.5 m 0 m PhotoScan - TLS - 0.5 m Pix4D - TLS SURE - TLS
Poznań side looking Patch (each 143 m ) statistic, relative to GSD (4 cm) 1 Model Point Spacing Patch 1 Mean STD Patch Mean STD PhotoScan.6-1.0 7.0 1.9 6.8 Pix4D.6 0.5 3.8-1.0.8 SURE 0.9 -.5 4.4 0.1 3.3
Poznań side looking Section
Poznań forward looking GSD ~4.5 cm Double and single overlap Point cloud from SURE
Poznań forward looking DSM difference + 0.5 m 0 m PhotoScan - TLS - 0.5 m Pix4D - TLS SURE - TLS
Poznań forward looking Patch (each 140 m ) statistic, relative to GSD (4.5cm) 1 Model Point Spacing Patch 1 Mean STD Patch Mean STD PhotoScan.3-1.4 3.3-1.1 3.0 Pix4D.4-0.8 3. -0.4 3.1 SURE 0.84 -.3 3. -3.6 3.9
Poznań forward looking Section
Katowice side looking GSD ~5.5 cm Single overlap Point cloud from SURE
Katowice side looking DSM difference + 0.6 m 0 m PhotoScan - TLS - 0.6 m Pix4D - TLS SURE - TLS
Katowice side looking Patch (15 m) statistic, relative to GSD (5.5 cm) 1 Model Point Spacing Patch 1 Mean STD PhotoScan 3.7 -. 3.5 Pix4D 3.9 -. 3.4 SURE 1.1-0. 3.1
Katowice side looking Section PhotoScan 54 5 50 48 46 44 4 40 38 36 34 3 30 8 6 4 0 18 16 14 1 10 8 6 4 0.5 1.5 1 0.5 0 Pix4D 54 5 50 48 46 44 4 40 38 36 34 3 30 8 6 4 0 18 16 14 1 10 8 6 4 0.5 1.5 1 0.5 0 SURE 54 5 50 48 46 44 4 40 38 36 34 3 30 8 6 4 0 18 16 14 1 10 8 6 4 0.5 1.5 1 0.5 0
Łódź forward looking GSD ~6 cm Double overlap Point cloud from Pix4D
Łódź forward looking What with SURE? Point cloud from Pix4D Point cloud from SURE
Łódź forward looking Section PhotoScan 4 3 1 0 4 6 8 10 1 14 16 18 0 4 6 8 Pix4D 4 3 1 0 4 6 8 10 1 14 16 18 0 4 6 8 TLS 4 3 1 0 4 6 8 10 1 14 16 18 0 4 6 8
Conclusions (preliminary) Single overlap provide possibility to create 3D point cloud from oblique images. Future work Examine reason of failure with DIM in SURE on forward looking images form Łódź.