I'm able to capture images from my webcam, but I want to be able to pan and tilt the camera as well as zoom the lens, but there doesn't seem to be much clear documentation on these functions and no tutorials. Is anyone aware of some resources out there on this subject?
I guess this really depends on your setup. Is your camera already attached to a pan and tilt rig?
If not, check out this tutorial from Sparkfun:
http://www.sparkfun.com/tutorials/304
This option requires some servos, an arduino, and some code written in Processing.
If the zoom and gimbals are already under driver control then you may be able to access them via the VIDIOC_*_EXT_CTRLS V4L2 ioctls; see the driver source for details.
If the webcam follows Pelco-D/P protocol,
just use the char string in c/c++ program and set the required bits for pan-tilt-zoom and send this string through the port. (generally USB port since serial/parallel port webcams are outdated)
The magnitude of pan-tilt-zoom can also be adjusted.
Related
I have two questions which I was struggling finding answers on the net for more than a week.
I'm writing a Windows service on Visual C++ 2017 which connects to Axis IP Cameras on our network and queries MJPEG streams using regular sockets. It successfully parses the streams and decodes JPEG images. Decoding done with OpenCV;
frame = cv::imdecode(data, IMREAD_GRAYSCALE)).
Q1. Although OpenCV uses a performance JPEG library as it claims: build-libjpeg-turbo (ver 1.5.3-62), decoding performance is surprisingly slower than .Net's System.Drawing.Image.FromStream(ms). Do you have any recommendation for a really fast JPEG decompression?
Q2. All I need to do with the received JPEG's is to check "regions of interest" if there is motion in there. These are production lines in a factory actually. The factory runs 24 hours and six days a week so there will be changing lighting conditions. Sometimes there won't be light at all so JPEG's will be with plenty of noise on them. Which OpenCV operations and algorithms you would recommend applying on the frames to have an understanding of if there is a motion at the ROI? Of course you can use plenty of operations on your matrices one after another but I need the shortest and most effective way to keep the resource requirements low as it will be doing this operation for plenty cameras and ROI's at the same time.
My system is with NVIDIA Video Card (I can use CUDA), Intel i7-7700, 16GB Ram.
Thank you!
This is not exactly an answer to your question, but it may even be a better approach.
Axis IP cameras have since long time an on-board motion detection engine than can be configured both via the camera web UI (on old camera models/firmware version it may require using Internet Explorer and the use of an embedded ActiveX control to do that) and via the VAPIX Axis HTTP camera API.
The same VAPIX HTTP API also has commands to receive motion levels and threshold for each configured motion area/window on the camera.
If you don't have a recent model that supports VAPIX version 3, you may still rely on VAPIX version 2, you can try issuing an HTTP GET request such as:
http:///axis-cgi/motion/motiondata.cgi?group=0,1
to get a HTTP multipart stream of the motion level and threshold data (i.e. for motion area 0 and 1).
For more detailed information, you can download the relevant VAPIX PDF documentation from the Axis website (may require an account and login).
I am doing a project regarding image processing and multiple person counting and was wondering, how exactly can I plug my ION AIR PRO PLUS video recording device (similar to a goPro), and use it as my 'webcam'? Basically, I want to plug it in and then access it via a live feed using Microsoft Visual Studio 2010 and OpenCV, and then do real time tracking of people walking.
What I am struggling with is accessing the external camera from my program. Anyone know how to do this?
The video camera has no wifi, only an hdmi output, RGB cable output and a USB.
Attach the USB cable and instantiate cv::VideoCaputre(0). In Linux local cameras have number indices I think in Windows should be the same.
Peter, In the past I have worked on camera products on Windows XP & 7. On windows usb cameras can be accessed using directshow.
You can implement a directshow filter for people tracking algorithm and fit it in the direct show pipeline soon after your camera plugin.
Here is a link to an application stack that may suit your use case(to give you an idea):
http://www.e-consystems.com/blog/camera/?p=1302
The recent windows operating systems that run WinRT, use a latest framework called MediaFoundation. As its very new there are some limitations we found when we tried to build similar applications.
To quickly see a preview out of your camera, pls google for "graphedit" and install it on a Windows 7 pc. Its a fairly simple tool. You can drag and drop your camera, if directshow is supported, then render its output pin and play for preview.
I do not think this is a standard webcam, it appears to work only as a mass storage device. One thing you can try is removing the micro sd card and connect it to the computer. This works on some cameras.
Assuming this does not work, one option would be to purchase an HDMI capture card. The YK762H PCI-E card costs around $40, and will allow you to use the camera with OpenCV, the videoInput library, or DirectShow.
The other option is to use the WiFi live preview. You would have to figure out the commands sent to the camera. This has already been done with the SJCam wifi cameras, the GoPro models, and Sony cameras such as the QX-10 and HDR-AS100V.
I am writing C++ class for managing multiple cameras and reading frames from them. Let's say it is wrapper for OpenCV. Currently I am finding cameras by trying to create devices from 0-10 range and If there is output I know that I've found working camera. I can always save internal IDs of those cameras to distinguish them but what If another camera is plugged in? It may break the order of IDs. So is there any way to distinguish OpenCV cameras for example by getting their hardware IDs?
I know this doesn't help you much, but the short answer is "No, OpenCV doesn't currently provide that capability."
According to the doc, any hardware ids are not properties you can retrieve using the get method or any other.
Having said that, if you're very intent on using OpenCV, I would still test the behavior of OpenCV 2.4.10 on various platforms and using various middleware and see how it behaves. If you get a consistent behavior, then you can run with it, but be somewhat ready for it to break in the future. What would work for you is that OpenCV is using various middleware in the backend, such as V4L, Qt, etc., and these are well-maintained and more-or-less consistent.
In retrospect, I would stay away from OpenCV's video interface altogether right now for commercial software, unless you're okay with the situation I described. Beware that OpenCV 3.0 videoio library is unstable at this point and has open bug reports.
I have been trying to access my analog camera via a EasyCap video capture device. Any code I try only picks the usb webcam or internal webcam. I guess that since video capture device is a video controller, opencv doesnt recognize it as a imaging device.
Can anyone conform if you cannot access analog cameras with opencv via a video capture device.
If so, then what other method can be used.
i struggled with the same problem (in my case within python instead of C++, although I am certain it will be the same root cause) and hope it helps!
the original thread + ANSWER
also relevant XKCD
Even for digital devices, OpenCV isn't good at reading them, it is good at processing them. The library has supply for generic webcams, of course; however it does not supply most of the commercial or industrial cameras.
In short, to decode, you should try using "video for linux" or "video for windows" libraries; or the device SDK itself. Since you are using a video2usb converter, you shouldn't have any problem accessing the analog camera through these software.
I am trying to replicate the image quality that is achieved when using the Logitech webcam driver to capture a still image.
The Logitech forum has several threads about the subject unfortunately they all point to a website which is down. such as here.
I am currently able to use DirectShow and a frame grabber to capture images, but they are nowhere near the quality of the snapshot button. Could anyone point me to the direction of a working c++/c example of a snapshot button?
After some research I found this about the Still Image pin, is this the correct method for implementing a snapshot like button?
The webcam I am using the c910 and is capable of taking 10 mega-pixel still images.
Thanks for any help.
My best guess, which I'll use to gather some upvotes (or downvotes), and which will be valid until someone disassembles the application or the driver, is:
Something alike http://www1.idc.ac.il/toky/videoproc-07/projects/superres/srproject.html was used at the application level to enhance the resolution of the images collected as a video.
Rationale: having a friend pulling his hair over simpler things inside the driver, I can only imagine how difficult it should be to code such an algorithm INSIDE the driver with extremely limited set of libraries.
I won't mind taking downvotes here, since I'm too interested in this subject, but please have some information available on the subject.
I did not have a chance to deal with this directly, however I suspect that high resolution images captured from the camera are a result of taking a sequence of images followed by "superresolution" post-processing. This functionality might be unavailable via DirectShow API, since it mostly covers video streaming. However, the camera driver might also make it available via Windows Image Acquisition API, where you might have better luck taking oversampled snapshots of the quality you are looking for.