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General / Underwater Photogrammetry with GoPros - Alignment failures
« on: July 27, 2016, 03:55:26 PM »
Hi everyone,
I am using some GoPros (Hero 4 Black) for underwater photogrammetry. In order to have enough overlap between pictures, I have extracted every 10 frames an image from the 4K video. As almost no exif data is available in the extracted frames, I copied the meta data from an usual GoPro picture to all of my frames.
During the acquisition, I also recorded the GNSS Positions ( I have a position every second). The Hero 4 records 30 frames per second, so when I extract 10 frames, I have three consecutive frames that are within the same second. For those frames, I give the same position.
When I try to align thoses images I met some failures. In some cases, PhotoScan can't find any matches between two overlaping pictures.
I cannot send in attachment the pictures as the zip file is too big. Here is a link to download it :
https://we.tl/WDPgM0brs8
In this zip file you can find two overlaping pictures, "GOPR0827 1232.jpg" and "GOPR0827 1233.jpg". Although the overlap is superior to 80%, I don't have any matches between them ("1232_Matches.png" and "1233_Matches.png").
For my whole project I have almost 1300 cameras. I have tested on a small set of cameras (9 cameras) and I cannot align them. I would like to know what I am doing wrong or what I should do.
Kind regards, Simon
I am using some GoPros (Hero 4 Black) for underwater photogrammetry. In order to have enough overlap between pictures, I have extracted every 10 frames an image from the 4K video. As almost no exif data is available in the extracted frames, I copied the meta data from an usual GoPro picture to all of my frames.
During the acquisition, I also recorded the GNSS Positions ( I have a position every second). The Hero 4 records 30 frames per second, so when I extract 10 frames, I have three consecutive frames that are within the same second. For those frames, I give the same position.
When I try to align thoses images I met some failures. In some cases, PhotoScan can't find any matches between two overlaping pictures.
I cannot send in attachment the pictures as the zip file is too big. Here is a link to download it :
https://we.tl/WDPgM0brs8
In this zip file you can find two overlaping pictures, "GOPR0827 1232.jpg" and "GOPR0827 1233.jpg". Although the overlap is superior to 80%, I don't have any matches between them ("1232_Matches.png" and "1233_Matches.png").
For my whole project I have almost 1300 cameras. I have tested on a small set of cameras (9 cameras) and I cannot align them. I would like to know what I am doing wrong or what I should do.
Kind regards, Simon
