Drone2Map artifacts in ortho mosaic

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3
12-28-2021 04:34 AM
Y_Chau
by
Occasional Contributor

I created an ortho mosaic in D2M. First with default settings and GSD 1. It contains artifacts all around the mosaic like below.

Pa.jpg

After reading some posts in this community, I changed the settings like, checked "rolling shutter optimization", changed initial to full and checked "use geometry verified matching". This produces even more artifacts and completely moves the ortho by few hundred meters.

Using default settings the overall quality is OK except for these artifacts. Please advise how can these issues be avoided.

Sincerely

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3 Replies
DanPatterson
MVP Esteemed Contributor

There other related links to the right of your post, for example,

Solved: Drone2Map imagery quality - Esri Community

which suggests "overlaps" setting


... sort of retired...
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FrankOuyang
Esri Contributor

As suggested by @DanPatterson, capturing more images using higher overlap ratio will help reduce the artifacts, such as increase it from 60% to 80% or 90%. This will increase processing time and the output point cloud size but it can significantly improve the quality of the output. 

Another thing to consider, from my experience, is try to fly the UAV at the solar noon when the shadow is minimized. By doing so, object/area of interest will have the best illumination which helps the photogrammetry algorithms identify objects and reconstruct them and eventually, reduce the chance of having artifacts. 

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DerrickWestoby
Occasional Contributor III

You really want to be flying with 70%+ overlap with SfM.   Keep in mind that this is based off the drone's altitude above ground level and an image footprint projected into the ground.  If you're flying over tall buildings, especially at low (<200ft) altitudes, the overlap in those areas is going to be insufficient.  You may have 70%/70% overlap at ground level, but 50%/50% on the building roof. 

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