I found this really cool tutorial about using OpenCV to create long exposure style effects from video, and I figured folks here might enjoy:
1 Like
This is pretty cool… Now what’s the price of that 8K video camera so I can have a decent still images resolution? 
1 Like
Sweet! 
This is one of the things that @David_Tschumperle added into G’MIC for me (I think we can even just pipe a video directly into a gmic command now to get an averaged output).
My results doing it with imagemagick at the time (wow, 2013):
https://patdavid.net/2013/09/faking-nd-filter-for-long-exposure.html#something-neat
These days the gmic command i think is just -avg?
[edit] - also, welcome back!
In G’MIC, you can do this kind of things with commands -average_files and -average_video:
$ gmic -average_files \*.jpeg -o averaged.jpg
and
$ gmic -average_video input.avi -o averaged.jpg
1 Like
I had forgotten that this is possible also with G’MIC! Thanks for the reminder. I’ve been using open CV a lot these days for photogrammetry work, so was naturally happy to see this little blog post. I like how information it is from a pedagogical perspective. Might use it in one of my classes!
@patdavid Thanks for the welcome! I’ve been gone all summer doing fieldwork in Italy and Kazakhstan, where, among other things, I was undertaking some systematic aerial drone surveys of archaeologically landscapes. Over the next several months in my lab, I’ll be processing hundreds of images with open drone map and hugin! Should be some cool results!
1 Like
That is really awesome. If you think we should write up an article to point out the FL/OSS aspect of this and get the opendronemap + Hugin folks a shoutout, just let me know!
Thanks Pat! I’ll be giving a conference paper on this in January, and will likely translate that too and post on my blog. I’ll be happy to link it all up here, and perhaps to turn it into a tutorial…
Isaac
1 Like
I don’t know if I should dig out this thread like I’m doing or start a new thread: my question does not relate directly to the topic of this thread, but to the last messages in it.
To satisfy my own curiosity I’d like to learn (and probably try) photogrammetry using drone images. It seems to be such a huge and complex application field of photography (the number of photogrammetry software as listed in wikipedia is daunting). @Isaac you mentioned it was your background (and maybe your day job?), would you be willing to share the conference paper you refered to in your message, and maybe to show me in which directions I should look first, not to waste too much energy and time. I’m more inclined to open source software, and preferably under linux.
Thanks a lot!
Cheers
denis
Hi @denis! Firstly, all my papers, conference presentations, and a lot of info and links can be found at my website http://isaacullah.github.io. The software I would recommend is Open Drone Map, and particularly the WebODM fork: github.com/OpenDroneMap/WebODM. Finally, check out my YouTube channel for some tutorials: https://www.youtube.com/channel/UCnXYZpB1oDiK44tV2w9ypvA. I’m currently teaching my GIS and imagery analysis course again this semester, so there will be new tutorials uploaded each week. I’ll get to processing drone imagery later in the semester. Let me know if you’ve got any questions!
Thanks a ton @Isaac, I really appreciate your help! I’ll take the time to explore your website and YT channel, and will take your offer to ask you questions if needed.
Cheers.
denis
1 Like
I just wanted to give an update about the digression (photogrammetry) from the initial topic, and thank you @Isaac a ton for the amount of information available on your websites. WebODM is ace and I’m actually digging in your YT tutorials for the analysis part. This YT channel and your blog posts (FLOSS list for example) are golden information to get started efficiently. If you don’t mind, I’ll probably contact you (out of this thread) with one or two questions about your workflow. Hope you’re enjoying nice fieldwork this summer.
Regards.
Denis
2 Likes
Very glad it’s helpful @denis! Yes, feel free to contact me if you have questions or just want to discuss more. I’m teaching the class again this semester, so may add some more videos…