11
votes
Accepted
what's the difference among rgb-d camera, depth camera, 3d camera, and stereo camera?
3D/Depth-Camera:
The most inclusive terms, only means that the camera gives you 3d data.
Stereo-Camera:
One kind of 3D-Camera, consists (in most cases) of two gray-scale Cameras.
RGBD-Camera:
A ...
- 1,355
9
votes
Camera selection for long range stereo vision system (up to 100 meters)
I still think this is off-topic, but it seems I need more space than a comment to show (answer?) why that is so.
You are starting from some performance specifications and are looking to get to a set ...
- 16k
4
votes
Accepted
Real-time video processing on video feed from a drone's camera
This AR.Drone provides SDK, therefore, you can access the images on real-time. It is fully compatible with Linux. They have examples also for smartphones. I believe android and iPhone. It has two ...
- 2,453
4
votes
Question for those who have experience using stereo cameras/module (e.g. ZED, DUO M, Bumblebee, etc.)
My experience with ready-made stereo solutions is that they (as @Ben has said) provide you with synchronized image pairs and well-defined baseline geometry.
If you are on a low-budget, and you have ...
- 892
4
votes
Why are two cameras mounted in paralle in stereo application?
Each camera needs to be defined by 6 variables (3 position, 3 orientation). This would mean that during the calibration process, a solver needs to find 12 variables. As this is done usually with an ...
4
votes
Accepted
Smart camera image processing on embedded GPU vs. in the cloud
Performance differences between using an embedded GPU vs. the cloud?
For your context (to my mind, gesture recognition would ideally be realtime), the latency of going over the cloud would push me ...
- 158
4
votes
Accepted
Visual Odometry terminology: Scale, Relative scale, absolute scale
What does the absolute scale mean? In this context, scale refers to
what property related to an image?
Essentially scale refers to the size of the object/scene that the camera sees.
As a projective ...
- 1,831
3
votes
Accepted
Difference between 3D Camera(using IR projection) and Stereo Camera?
"3D camera" is a generalisation that covers sensors that can observe a point-cloud or depth map of the scene they are observing.
Some 3D cameras use a projector (via various ways) to improve the ...
- 892
3
votes
Stereo Camera calibration with different camera types
It looks like what I saw when a colleague of mine was working with fisheye lenses; I found this post after doing an image search for "rectify fisheye image" and following the link from this picture.
...
- 16k
3
votes
Camera selection for long range stereo vision system (up to 100 meters)
I'll try to explain this in terms of software. Firstly, it is just next to impossible to have 100 metres (practically, 3 metres is like the best depth accuracy) and we need to be sure that the cameras ...
3
votes
Accepted
How to produce a continuous variation of a discontinuous function?
It happens many times that set-points fed in our systems do change in a step-wise manner. Your intuition of filtering those variations is correct and represents a common practice.
Here I'd give two ...
- 3,995
3
votes
Real-time video processing on video feed from a drone's camera
I bought an AR done 2.0 for my research.
I used Labview to process the realtime video feed from either the bottom camera of the drone or the front camera.
You can read more details on how to setup ...
- 31
3
votes
Accepted
I am making a Ping pong-playing robot using two cameras to trace the ball (3D vision),what is the minimum Frame rate of the cameras?
The movement of the ping pong ball is going to be ballistic, so you really only need to know its 3d position in 3 different locations in order to fully constrain its motion. In reality, you will ...
- 1,919
3
votes
Accepted
Question about Lens distortion
You can only say that the distorted image coordinates are in the range (0-240, 0-180), since that's the image you are starting with. Typically you assume the dimensions of the undistorted image as ...
- 1,692
3
votes
Accepted
Position vs Image based visual servoing?
The problem in both cases is to move the robot tool to some pose relative to an object. Let's assume the camera is attached to the end of a robot arm (eye in hand case) so we will consider this a ...
- 1,692
3
votes
What is the relation between FOV, Focal Length and Sensor size in a Pin hole Camera Model?
The field of view can be shown to be
$$
\theta = 2 \tan^{-1} \frac{D}{2f}
$$
where $D$ is the dimension of the sensor (width or height) and $f$ is the focal length.
You can derive this easily using ...
- 1,692
3
votes
Accepted
How do I record video from webots simulated cameras?
Webots uses ffmpeg to create movies out of JPG images. The code snippet in Webots is located here. But since Webots embeds ffmpeg, you should be able to use it pretty easily from your controller ...
- 620
3
votes
Detecting door blockage using computer vision
In your example image, you show what appears to be a fixed camera feed (for example, a security camera). If it is safe to assume that this is a fixed camera feed, this becomes much easier, since we ...
- 770
2
votes
Accepted
Using an RGB + Depth Camera to locate X,Y,Z coordinates of a ball
The critical part is the registration between depth data and RGB data. If the registration is calibrated properly then you can just extract the depth for the particular target pixel (X,Y), using ...
- 1,377
2
votes
Accepted
Syncing camera with other signals
Cameras that support syncing will probably do so via an external signal. Google "genlock" or "timecode sync" or "external trigger" to get started. For instance, here's a link to external trigger ...
- 4,385
2
votes
Analogue video to digital
You will need to have on-board processing if you plan to go with real time processing and the low latency premise. There is no other way around it, since transmitting the signal will introduce sizable ...
- 550
2
votes
Perspective n Point - RPnP algorithm
Since you only have 4 points, you should use the P3P algorithm. 3 points give you up to 4 solutions, and you need a fourth point to decide which one is correct. So 4 is the minimum number of points ...
- 191
2
votes
Difference between 3D Camera(using IR projection) and Stereo Camera?
This isn't an answer so much as a series of questions to get you to consider an appropriate solution.
I will, as usual :-), echo @BendingUnit22 and @Gouda - you appear to be fixated on a particular ...
- 16k
2
votes
Image registration with ground plane for surround view
I don't know what the proper way to do this is but I can give you ideas to make it better:
define an exact transformation for each camera. You could calibrate each camera using a grid pattern and by ...
- 571
2
votes
Accepted
My Plug Says It's USB, I can't Identify
USB is more than just a connector. It is a standard communications protocol, voltage levels, and even wiring colors.
I suggest you get a standard USB cable, cut it in half, then splice in your ...
Ben♦
- 5,825
2
votes
Accepted
OpenCV get topdown view of planar pattern by using intrinsic and extrinsic from cameraCalibrate
Added
OK, guys, simple mistake. I previously used warpPerspective to warp images instead of restoring. Since it works that way, I didn't read the doc thoroughly. It turns out that if it is for ...
- 151
2
votes
Depth cameras with varying illuminations
depth cameras are super cool. I have never worked with them before, but guess what? I have an opinion! lol.
Have you considered using a lens to filter out the direct sunlight as a "cover" (kind of a ...
- 361
2
votes
Trigger two usb cameras at the same time
As you say, you can't trigger them at the exact same time without hardware capable of doing so. Some IMU's supply an external trigger pin, and I see no reason why you couldn't buy cameras that have a ...
- 151
2
votes
Accepted
How do I set all objects in my scene to be aligned with respect to the camera in Unity 3D?
I think the function you're looking for is TransformPoint(Vector3 position). You can describe something in coordinates that are local to the camera and use the <...
- 16k
2
votes
Accepted
How to plot the 3D camera trajectory from a VSLAM output
That's simple.
If you use matlab or opengl what you need to do is just drawing 3 axis at (tx,ty,tz).
You need to convert quaternion to rotation matrix.
(qx,qy,qz,qw) -> R(3x3 matrix)
where each col ...
- 1,527
Only top scored, non community-wiki answers of a minimum length are eligible