The Stereo Pair 3D Measurement process allows you to select a common point from two stereo images and calculate an elevation value for that point.There are three steps in creating a DEM that are crucial to generating acceptable results: epipolar image creation, image matching, and DEM geocoding.
Epipolar Image Creation - The creation of epipolar images is an essential processing step in DEM extraction. Epipolar geometry describes the geometrical constraint between two frame images of a stereo pair. It represents the fact that a ground point and the two optical centers lie on the same plane. This means that for a given point in one image, its conjugate point in the other image must lie on a known line in the second image. By creating epipolar images, the search space for finding corresponding image points in automatic image matching is reduced. For information about building epipolar images for the use with DEM Extraction Wizard, see Building Epipolar Images.
Image Matching - Image matching finds the conjugate points on both the left and right images which correspond to the same ground feature. The output of the image matching procedure is called a parallax image, in which the x-coordinate difference (along epipolar lines) between the left and right image is stored and is used to build the DEM. Thus, the quality of image matching largely determines the quality of the output DEM.
DEM Geocoding - DEM geocoding re-projects the DEM from the epipolar projection to the user-specified output map projection and units. This step involves the filling of failed pixels and the resampling to a pixel spacing specified by the user. When GCPs are provided, the absolute orientation of the computed terrain model is performed in this step.
Posted by Jorg Mohnen |
On 18 May 2018 |
Updated on 18 May 2018 |
Development of the OLI-2 and TIRS-2 instruments is progressing, and both are on target for integration with the spacecraft in mid-2019. The instruments are rebuilds of those onboard Landsat 8; however, TIRS-2 has improved stray light performance through improved telescope baffling and improved position encoder for the scene select mechanism, both issues on the Landsat 8 TIRS instrument. The Landsat 9 ground system and Mission Operations Center (MOC) are progressing through their respective milestones. Landsat 9 remains on schedule for a December 2020 launch from Vandenberg Air Force Base..
Join us with our Drone Swarm Mapping technologies at the NAB in Las Vegas this year. Drones are flying at there own Aerial Robotics and Drone Pavilion this year. Don't forget to attend a number of sessions including aerial cinematography techniques, live broadcasting and US Part 107 certification. Our attendees will get to see our new product launches including electronics for swarm mapping and our SDK's based on Positioning, Ethereum, FCL, Mavros, OctoMap, OMPL, ROS, and web3.
NAB Show 2018 is home to the world’s largest collection of vendors driving the future of media and entertainment. ..
EarthOnDrive will be presenting its latest technologies and mapping software at the GeoBusiness, U.K. on May 22-23, 2018. The GEO Business show has grown every year since its inception, and the 2018 show looks set to be the most successful show to date with more exhibition space and a brand new seminar program. The event will return to the Business Design Centre, in London, UK, May 22-23.
Since its record-breaking 2017 event last year, which welcomed 2,386 geomatics and geospatial professionals from around the world (a 48 percent increase since the launch in 2014), the exhibition has expand..
Developers of the first real-time ray-tracing and global illumination Texturing Solution based on wavelet theory, WavGen Pro allows computer graphics users working with Maya 2017/18 and 3D Studio Max 2017/18 3D the abilithy to model, render, and animate literally terabytes of imagery and thousands of hypershade nodes. WavGen announces new and updated plugins for Linux, OSX, and Windows, that further integrate wavelet technologies with Autodesk’s line of 3D modeling, rendering, and runtime applications. We now have exporter plugins for work flows in gaming (Unity, Scene Graph, Unreal, Cry..