duckworthd

8 ms·

61.
by duckworthd 6y ago
It's hard for me to say how precise camera position and direction needs to be. We use COLMAP to estimate both via multi-view stereo.
62.
by duckworthd 6y ago
Pictures are pictures, even as video frames :)
63.
by duckworthd 6y ago
The model is trained to reconstruct what is observed, but not what is obscured. If you look closely at our videos, you'll notice some parts of the scene are blurry -- those parts weren't seen often enough to learn well. If you loo
64.
by duckworthd 6y ago
I'm actually quite new to the field, and I'm not even sure what to compare against nor how to compare it. What's typically measured and how?
65.
by duckworthd 6y ago
The model does not explicitly learn to segment images. The answer is unfortunately more difficult to explain than a HN comment bears. I encourage you to read the paper for more details. https://arxiv.org/abs/2008.02268
66.
by duckworthd 6y ago
Consider? Yes. Try? Nope!
67.
by duckworthd 6y ago
1) My bread and butter for the last 10 years has been machine learning. When all you have is a hammer... 2) We don't extract surface contours, we learn a volumetric radiance field! To oversimplify, we learn a (smooth) function that, gi
68.
by duckworthd 6y ago
I don't know! I'm not familiar enough with the field to say.
69.
by duckworthd 6y ago
There is currently no way i'm aware of to accurately reconstruct a moving 3D scene. Sorry! Ask us again in a few years :)
70.
by duckworthd 6y ago
I'm a bit new to the field myself, so I'm afraid I can't provide any contacts. Ask me again in a couple of years. The method presented here wouldn't do well with your problem either. 3D reconstruction of moving objects i
71.
by duckworthd 6y ago
I'm not sure I understand your question. If the question is, "can you reconstruct a (static) scene from the frames in a video?", the answer is yes! If the question is, "can you reconstruct a scene with people and other m
72.
by duckworthd 6y ago
> This looks amazing! Congratulations. Thank you! > What was the most challenging aspect of this? Wow, that's hard to say! Our work truly stands on the shoulders of giants (Mildenhall et al, 2020). I can list off a few challenges
73.
by duckworthd 6y ago
At this point, this method is only good at reconstructing parts of the scene that are well-photographed. You'll notice that our video for Sacre Coeur has some blurry bits, particularly the staircase in front of the Basilica. That'
74.
by duckworthd 6y ago
It's a little hard to describe from scratch, but let me do my best. The method is unattended, in the sense that it's photos + camera parameters in and scene representation out. The photos should all be of the same scene (e.g. the
75.
by duckworthd 6y ago
That's a really cool idea! This technology does a fantastic job at reconstructing static scenes. The moving objects -- people, cars, even flora -- are out of scope here. Why? It's really hard to build a 3D model of something you
76.
by duckworthd 6y ago
According to Wikipedia, "Photogrammetry is the science and technology of obtaining reliable information about physical objects and the environment through the process of recording, measuring and interpreting photographic images and pat
77.
by duckworthd 6y ago
The magic of this method is that we don't construct a "geometry" the same way one might think. There are no triangles or textures here. Instead, we train a machine learning model to predict the derivative of the color and opa
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by duckworthd 6y ago
On the order of hundreds to low-digit thousands worked well for us. These photos contain a lot of occluders like tourists, and we needed to have enough views of the subject in question to build a good 3D scene representation.
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by duckworthd 6y ago
Thank you :)
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by duckworthd 6y ago
We use images from the Image Matching Challenge 2020 dataset. If you look at the Appendix, we list how many images we use and the process by which they were chosen. Download and have a look! https://vision.uvic.ca/image-mat
81.
by duckworthd 6y ago
Original author here. AMA!
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by duckworthd 8y ago
My $0.02. I've been working a 4 day/week schedule for 1.5 years now. Initially, I took the time off to lead a nonprofit volunteering project but quickly got burned out (4 days work, 1.5~2 days nonprofit work = 5.5~6 days/week
83.
by duckworthd 8y ago
A couple of questions, 1) In the motivation for the adjoint method, is u given along with A and C? I don't see how to compute u^T B without u. 2) How do a(t), da(t)/dt, and dG(..)/dh relate to A, B, C, u, and v from the motiv
84.
by duckworthd 8y ago
Yes! Though this answer has some subtlety. tf.while() will run several iterations in parallel but this is not the same as _batching_ those same iterations. For that, you'll need to use the experimental parallel_for feature [0]. Using t
85.
by duckworthd 8y ago
There are two reasons, 1) Take a closer look at tf.hessian()'s implementation. Notice the tf.while() loop, calculating tf.gradient() for each coordinate of the first gradient? That doesn't happen in parallel! Plus, you need to kno
86.
by duckworthd 8y ago
My $0.02. I've been using JAX for a while now. A paper I'm an author on ( https://arxiv.org/abs/1806.09597 , a follow-up to https://news.ycombinator.com/item?id=18633215 ) resulted in an algorit
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by duckworthd 12y ago
The best start I ever had to Artificial Intelligence was via UC Berkeley's CS188 course[1]. This course takes you through the very foundations of AI, from search to planning to basic probability theory. It's been imitated at unive