# Time Lapse Videos From Community Photos | Two Minute Papers #5

## Метаданные

- **Канал:** Two Minute Papers
- **YouTube:** https://www.youtube.com/watch?v=UePDRN94C8c
- **Дата:** 25.08.2015
- **Длительность:** 2:22
- **Просмотры:** 4,140

## Описание

Building time lapse videos from community photographs is an incredibly difficult and laborious task: these photos were taken at a different part of the year, from different times of the day, with different viewpoints and cameras. A good algorithm should try to equalize these images and bring them to a common denominator to get rid of the commonly seen flickering effect. Researchers at the University of Washington and Google nailed this regularization in their newest work that they showcased at SIGGRAPH 2015. Check out the video for the details!

Photograph credits in the video:
Flickr user dration, Zack Lee, Nadav Tobias, Juan Jesus Orío and Klaus Wißkirchen. 
In the original paper, photographs from the following Flickr users were reproduced under Creative Commons license: Aliento Más Allá, jirihnidek, mcxurxo, elka cz, Daikrieg, Free the image, Cebete and ToastyKen.

The paper "Time-lapse Mining from Internet Photos" is available here:
http://grail.cs.washington.edu/projects/timelapse/
Disclaimer: I was not part of this research project, I am merely providing commentary on this work.

Thumbnail background by Davidw: https://www.flickr.com/photos/davidw/2297191644/
https://creativecommons.org/licenses/by/2.0/

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## Содержание

### [0:00](https://www.youtube.com/watch?v=UePDRN94C8c) Segment 1 (00:00 - 02:00)

Hey there Fellow Scholars I am Károly Zsolnai-Fehér and this is Two Minute Papers, where we learn that research is not only for experts, it is for everyone. Is everything going fine? I hope you are all doing well and you're having a wonderful time. In this episode we're going to look at a time-lapse videos Let's say you would like to build a beautiful time-lapse of a Norwegian glacier. The solution sounds quite simple. Just mine hundreds of photos from the Internet and build a time-lapse video from them. If we just cut a video from them where we put them one after each other we will see a disturbing flickering effect. Why? because the images were taken at a different time of the day so the illumination of the landscape is looking very different on all of them. They are also taken at a different time of the year and from different viewpoints. Moreover, since these images are taken by cameras, different regions of the image may be in-focus and out-of-focus. The algorithm therefore would have to somehow equalize all of the differences between these images and bring them to a common denominator. This process we call regularization and it is a really difficult problem. On the left you can see the flickering effect from the output of a previous algorithm that was already pretty good at regularization but it still has quite a bit of flickering. Here on the right you see the most recent results from the University of Washington and Google, compared to this previous work. The new algorithm is also able to show us these beautiful rhythmical seasonal changes in Lombard St., San Francisco. It can also show us how sculptures change over the years and I feel that this example really shows the possibilities of the algorithm. We can observe effects around us that we would normally not notice in our everyday life simply because of the reason that they happen too slowly. And now here's the final time-lapse for the glacier that we were looking for. So, building high-quality time-lapse videos from an arbitrary set of photographs is unbelievably difficult and these guys have just nailed it. I'm loving this piece of work! And, what do you think? Did you also like the results? Let me know in the comments section. And for now, thanks for watching and I'll see you next time!

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*Источник: https://ekstraktznaniy.ru/video/14963*