I am currently working on the "Xtion pro live" by using "OpenNI" library.
The problem is that the Xtion must be vertically placed (along a wall). The problem is that in this position the user calibration always fails, so it is impossible to get the Skeleton info.
So, I would like to know how to fix this issue, I suppose there is something that I didn't understand about "GetSkeletonCap().RequestCalibration()" or with the "SampleConfig.xml" file. After a lot of research however I am still stuck.
Try moving the user, followed by the camera in 360degree circumference around the subject keeping the vertical positioning of the camera the same all the way through. It may detect optimal angle on the depth sensor. We did this twice with the kinect and it worked.
Also make sure the room is well lit.
Related
Not sure where to ask this. Please redirect me if SO is not the place.
I want make a web app that accurately tracks pose in a stationary video of someone pedaling a stationary bike. The joints can be marked with some stickers to make the process easier and more accurate. Basically, I want to do what does this app.
First i tried markerless tracking using pose estimation models such as mediapipe's Blazepose and google's MoveNet. However, these are not accurate enough. I would also like to track some additional landmarks (ball of the foot,...).
Then I tried OpenCV.js's Lukas-Kanade optical flow method. But the algorithm lost the tracked point quickly. Even when i placed a colored tape on the part of the body that i wanted to track.
I also tried template matching a single marked point in opencv but it was not very robust, and it would probably not work well when using more markers.
What other methods can I try? Since the app i send the video of requires stickers to be placed, I though it is using something like Lukas-Kanade. But as I said, when I tried it, it wasn't able to track the marked point. Because the app is only on iOS I thought it may be using this API. However, this is only my speculation.
Edit: added example video: https://www.youtube.com/watch?v=eCNyyABfWSE
I tried shooting in slowmo to have more fps, but the quality suffered because of this. Also i didn't have blue or green tape so I had to use yellow, which is not very visible on the sweater or on my wrist. But the markers on the pants should be trackable right?
The problem I'm facing is similar and closely related to this issue on Github but that's for Unity SDK, my question is for iOS SDK.
I want to achieve the same thing. Let me explain, basically I have pixel grid in which each pixel'd have equal size. Pixel is set to be 10m x 10m in real world. The thing I experienced is that if pixel locates towards the northern or southern part of the world, its size is stretched like the following.
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But when such pixel locates along the equator line, or simply along the middle part of the world. It looks ok like following
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There's no problem about rendering stuff, or positioning on Mapbox. The thing is I want every pixel to be square visually.
I've read along on the issue I linked above. It relates to mercator and the world is not flat thus makes this visual happens. It looks stretched along the northern and southern part of world map. As well, I found out that there's no equal functionalities as presented in Unity SDK for this particular problem on iOS SDK, so I'm not sure which approach I should go on to solve this solution.
How can I achieve equal size of pixel on the gridline on mapbox using Mapbox iOS SDK? Is there already solutions provided in the SDK?
FYI.
My requirement also needs real distance as shown on the map. I'm not sure it'd affect the solution as presented in the link I linked above.
I use Mapbox iOS SDK 3.7.6
My initial approach is straightforward as I fix the size of pixel to be 10m x 10m, then calculate its corresponding latitude and longitude value. Use those values to position them in Mapbox treating entire world map as a tilemap. Anyway I didn't take into account mercator in calculation, so this might be the case, if so then how to do just that? Only thing from my checking as available in iOS SDK is MGLMapView's metersPerPoint(atLatitude:). No tile ID system, or Conversions.cs as seen on Unity SDK. So i'm not sure on how to go on and solve this problem.
Update
I managed to solve it and made it work!
I'll come back and post the solution.
My solution is to port sphericalmercator.js to swift, then use it in code. I use a fixed zoom level of level 22 as its visual look is closest to what I need and also before. I went with the approach to at least have it looks visually equal not necessary its physical size.
Thanks to a hint in this answer on how to use sphericalmercator.js.
Anyway from my testing with it, tile size as set when you creating an instance using SphericalMercator seems not to be in effect no matter what value I set. Only zoom level will determine number of tiles across the world map for you. Note that upper-left corner is origin which is 0,0 tile index. Lower zoom level value will generate large tile size, but higher value will generate smaller tile size.
You can take a look as SphericalMercator-swift; the code I ported from origin JS implementation as linked above along with how to use it to get tile index, or bounding box of longitude/latitude in swift code in order to do rendering stuff on top of Mapbox.
After testing with default and custom marker/model of various size and distance, I concluded that the reason my AR models are having seizure (jittering/flickering/shaking like mad) is because of my hand movement. When the (phone) camera is at rest, the model is stable when the camera is stable.
Because the intention is to share the end product with the public (or anyone whose phone supports WebRTC), I can't calibrate the AR camera, because that would only fix my (phone) problem, not the other audience's.
Is there a setting in AR.js or ARToolkit that governs the sensitivity of the camera?
In case you are facing hard mad movements/hyper-sensitivity shaking of images with Ar.JS, and you are using multiple markers in the same page, the solution is to add a <a-entity camera></entity> inside the <a-scene> that contains the markers.
This avoids the automatic camera(s) created by a-frame, and makes everything more stable.
You could use the object position and orientation from AR.js and average that over a few frames to smooth things out.
I want to make a movable camera that tracks an opened hand (toward the floor). It just needs to track the opened hand but it has to also know the rotation (2d rotation).
This is what I searched for so far:
Contour- As the camera is movable, the background is unknown, even the lighting is not fixed. It's hard for me to get a clear hand
segment in real time.
Haar- It seems this just returns a rect and can't deal with rotation.
Feature detect- A hand doesn't have enough detail for this.
I am using the Opencv Unity plugin to do this.
EDIT
https://www.codeproject.com/Articles/826377/Rapid-Object-Detection-in-Csharp
I see another library can do something like this. Can OpenCV also do this?
I'm trying to develop a mini "Around Me" like using camera, compass and location. I would like to display place's images on my screen.
For the moment I have my location and my orientation with compass. I would like to know how can I determine the position of the place I want to display.
Thanks for your help ;)
Once you have relative distance and bearing, which you can determine from two points in the same coordinate space using algorithms found on this page, figuring out where a known coordinate is with respect to a known viewpoint is basically a perspective projection, the math is outlined on this Wikipedia article. The rotation of the camera is given by the compass, and the tilt by the accelerometer (the position is of course, GPS).
I'm trying to find a better document - there are a couple of extra things to consider - like the camera parameters etc, but this is a good starting point.
If it's too involved (like if you're not comfortable with rotation matrices) we can break it right down to the simple trig.
The code in the iPhone ARKit project does this, and quite a bit more. While you may not be able to use their complete library, it is a great reference on the subject of augmented reality.
Check out 3DAR, it lets you add an AR view to a MKMapView app very easily. There's a video tutorial on this process, as well as some sample code, on the 3DAR site, www.3dar.us
You can create a location based AR app in Junaio. It's an AR browser. Free to use and deploy in (as long as it's not a custom app and in Junaio).