MASI: Modules for Aerial and Satellite Imagery

Transcription

1 MASI: Modules for Aerial and Satellite Imagery Product Descriptions and Typical Applied Cases Dr. Jinghui Yang Sept. 18, 2017 File Version: v1.0 VisionOnSky Co., Ltd.

2 Contents 1 Descriptions of software modules Module of automatic DSM extraction from aerial images Module of orthorectification of aerial images Module of automatic DSM extraction from satellite images Module of orthorectification of satellite images Module of pansharpening of satellite images Module of DSM2DTM Module of change detection of surface height Module of UAV image processing Typical applied cases and results... 3 Case 1: Generation of dense and accurate DSM... 3 Case 2: Colored point clouds for simple construction of 3D scene... 5 Case 3: Automatic finding of new buildings... 6 Case 4: Automatic DSM generation of ZY3 three line array images Case 5: DSM extracted from very high resolution satellite image Case 6: DSM to DTM Case 7: Pansharpening of Worldview 2 images Case 8: Pansharpening of QuickBird images Case 9: Ortho rectification of an image block Case 10: DSM generation from UAV images Case 11: Point clouds extracted from aerial images... 17

3 1 Descriptions of software modules 1.1 Module of automatic DSM extraction from aerial images Providing the orientation list of aerial image block, the parameters of aerial camera and the image block, the DSM of the whole area covering the block is extracted. The grid size of DSM can be set as high as the GSD of aerial image. The module support different rotation system depicting camera pose, i.e., omega phi kappa, phi omega kappa, and kappa phi omega as well as rotation matrix. It means that all formats of the orientation list exported from aerotriangulation software can be used in the module. Almost all frame cameras are supported, such as DMC I/II/III, UCD, UCX, UltraCam Falcon, UltraCam Eagle, RCD 30, PhaseOne, Hasselblad, SWDC 2, SWDC 4, etc. The module can also export the point clouds, epipolar image and disparity image. The main steps / functions are automatic generation of batch file which include all commands of stereo matching for an image block, epipolar resampling, stereo matching, dense point clouds generation, DSM generation from an individual stereo model, mosaic of individual DSMs, interpolation of none data area in the DSM, outliers (small spot of errors) removal, refining. Users can operate the module very flexibly. People can start multiple processing of stereo matching, which is a relatively computation extensive, according to the computational resources on the machine. You can also stop any step in the course of the whole procedure as long as you re start the step next time. 1.2 Module of orthorectification of aerial images Providing the orientation list of aerial image block, the parameters of aerial camera, the image block, and the DEM/DSM, the orthomap of each image in the block is generated. The ortho rectificated image can be mosaicked to form a big image. Along with point clouds, the colored point clouds (RGB point clouds) can also be generated. Almost all frame cameras are supported. 1.3 Module of automatic DSM extraction from satellite images Providing the satellite stereo (or triple stereo) images and the corresponding RPC parameters, the module first improve the orientation parameters by bundle adjustment on the stereo/ triple image, and then generate DSM from the extracted 3D points. The grid size of DSM can be set as high as the GSD of satellite image. Most commonly used satellite sensors are supported, such as Worldiew 1/2/3/4, GeoEye, Ikonos, ZY3 01/02, Pleiades 1A/1B, SPOT 6/7, etc. The module can also export the point clouds, quasi epipolar image and disparity image. The main steps / functions are bundle adjustment on stereo / triplet images, quasi epipolar resampling, stereo matching, dense point clouds generation, DSM generation, interpolation 1

4 of none data area in the DSM, outliers (small spot of errors) removal, refining. 1.4 Module of orthorectification of satellite images Providing the RPC file, satellite image and the DEM/DSM, the orthomap of the satellite image is generated. Along with point clouds, the colored point clouds (RGB point clouds) can also be generated. Most commonly used satellite sensors are supported. 1.5 Module of pansharpening of satellite images The module can combine a lower resolution multispectral image and a higher resolution panchromatic image both covering a same area, and produce a new higher resolution image, in which not only the color content are remained but also the spatial details are enhanced by adopting the higher resolution panchromatic image. The algorithm in the module can achieve a maximum enhancement of its spatial details at the expense of a minimum multispectral distortion for the multispectral images. Most commonly used satellite sensors are supported, such as Worldiew 1/2/3/4, GeoEye, Ikonos, ZY3 01/02, Pleiades 1A/1B, SPOT 6/7, etc. 1.6 Module of DSM2DTM Providing a raster form 2.5D DSM, the module is to transformer DSM to DTM with multilevel triangle based ground filtering. The DSM can be extracted from UAV image, aerial image, satellite image as well as LiDAR points. 1.7 Module of change detection of surface height Based on the heights change of surface, the module can detect change of the heights change and calculate the value of changed height. 1.8 Module of UAV image processing Providing the orientation list of UAV image block, the parameters of camera and the image block, the module can generate dense DSM and orthoimage. The main steps / functions of the module include undistortion of camera s lens, overlapping analysis of images in a block and optimal section of stereo models, stereo matching, mosaic, point clouds generation, DSM generation and ortho rectification. 2

5 2 Typical applied cases and results Case 1: Generation of dense and accurate DSM 3

6 Color shaded DSM extracted from DMC images, grid size: 8 cm 4

7 Case 2: Colored point clouds for simple construction of 3D scene Colored point clouds generated from SWDC 4 images, grid size: 20 cm 5

8 Case 3: Automatic finding of new buildings DSM of previous phase generated from SWDC 4 images by MASI software, grid size: 15 cm 6

9 DSM of next phase generated from UAV images by Pix4D software, grid size: 10 cm 7

10 Height difference above 2 m, difference = (next DSM previous DSM), grid size: 10 cm 8

11 Automatic finding of new building and its accurate height ( ) 9

12 Case 4: Automatic DSM generation of ZY3 three line array images The color shaded DSM extracted from ZY 3 three line array images, grid size: 3.5 m 10

13 Case 5: DSM extracted from very high resolution satellite image The color shaded DSM extracted from Worldview 1 stereo images, grid size: 0.7 m 11

14 Case 6: DSM to DTM DSM extracted from SWDC 4 images by MASI software, grid size: 20 cm DTM transformed from DSM, grid size: 20 cm 12

15 Case 7: Pansharpening of Worldview 2 images Panchromatic Multispectral Pan sharpened image 13

16 Case 8: Pansharpening of QuickBird images Pan sharpened QuickBird images, (a), (b): Panchromatic images; (c), (d): Multispectral images; (e), (f): Pan sharpened images 14

17 Case 9: Ortho rectification of an image block Mosaic of ortho rectificated images of a block 15

18 Case 10: DSM generation from UAV images DSM extracted from UAV images, grid size: 15 cm 16

19 Case 11: Point clouds extracted from aerial images Point clouds extracted from DMC II camera, grid size: 8 cm 17