I am using the directshow.net to capture video from the camera. The video is visible on a form. Can someone tell me how I can take a snap of it as an .NEt Image object. I need to take snaps of it intermittently.
I believe there is a sample application that shows you how to do this with DirectShow.net. When you download the SDK, look for the DxSnap demo. This shows how to take a screenshot of a webcam's video stream. You can modify it to fit your scenario but this should be all you need.
Even on this site, however, Microsoft recommends that you use WIA (Windows Image Acquisition) to accomplish this instead. Just in case you have the option and haven't come across this before, here is a tutorial on how to get started:
http://channel9.msdn.com/coding4fun/articles/Look-at-me-Windows-Image-Acquisition
Related
There are a quite a few of sources to get a video stream from webcam into a picturebox embedded in a userform.
Preview a camera in DirectShow and capture a still image - in VB.net
How do i use attached webcams to take still image in my application
However, I am trying to do something a little neater, basically have a the preview of the video stream from webcam in a control that is embedded directly into the sheet rather than on a floating userform. I am not sure if this possible. I would very much appreciate any pointers.
(Answer from TnTinMn's comment - Posting as an answer to remove from 'Unanswered' queue)
If you can write a .Net WinForm UserControl to view your video stream, then you should be able to produce a ActiveX UserControl that you can utilize in Excel.
Get the Microsoft InteropForms Toolkit 2.1 .
Even though it was originally intended to allow .Net UC usage in VB6, it works fine to write UCs for use in Excel.
As a test, I just wrote one that used the Windows Media Player and it played the video fine as a UserControl on the worksheet.
Start VS as an Admin as it needs to be able to register the control.
I would say build a Form with TopMost = True
Then you can display your webcam video in this Form
and put it anywhere you want.
We have a c# application that performs processing on video streams. This is a low-level application that receives each frame in Bitmap format, so basically we need 25 images each second. This application is already working for some of our media sources, but we now need to add a webcam as an input device.
So we basically need to capture bitmap images from a webcam continuously so that we can pass all these frames as a "stream" to our application.
What is the best and simplest way to access the webcam and read the actual frames directly from the webcam as individual images? I am still in the starting blocks.
There are a multitude of libraries out there that allows one to access the webcam, preview the content of the webcam on a windows panel and then use screen capturing to capture this image again. This, unfortunately, will not give us the necessary performance when capturing 25 frames per second. IVMRWindowlessControl9::GetCurrentImage has been mentioned as another alternative, but this again seems to be aimed at an infrequent snapshot rather than a constant stream of images. Directshow.Net is mentioned by many as a good candidate, but it is unclear how to simply grab the images from the webcam. Also, many sources state a concern about Microsoft no longer supporting Directshow. Also, implementations I've seen of this requires ImageGrabber which is apparently also no longer supported. The newer alternative from MS seems to be Media Foundation, but my research hasn't turned up any working examples of how this can be implemented (and I'm not sure if this will run on older versions of windows such as XP). DirectX.Capture is an awesome library (see a nice implementation) but seems to lack the filters and methods to get the video images directly. I have also started looking at Filters and Filter Graphs but this seems awfully complex and does feel a bit like "reinventing the wheel".
Overall, all the solutions briefly mentioned above seem to rather old. Can someone please point me in the direction of a step-by-step guide for getting a webcam working in C# and grabbing several images per second from it? (We will also have to do audio at some point, so a solution that does not exclude video would be most helpful).
I use AForge.Video (find it here: code.google.com/p/aforge/) because it's a very fast c# implementation. i am very pleased with the performance and it effortlessly captures from two HD webcams at 30fps on an 8 year old PC. the data is supplied as a native IntPtr so it's ideal for further processing using native code or opencv.
opencv wrappers emgu and opencvsharp both implement a rudimentary video capture functionality which might be sufficient for your purposes. clearly if you are going perform image processing / computer vision you might want to use those anyway.
As dr.mo suggests, Aforge was the answer.
I used the tutorial from here: http://en.code-bude.net/2013/01/02/how-to-easily-record-from-a-webcam-in-c/
In the tutorial, they have an event handler fire each time a frame is received from the webcam. In the original tutorial, this bitmap is used to write the image to a PictureBox. I have simply modified it to save the bitmap image to a file rather than to a picturebox. So I have replaced the following code:
pictureBoxVideo.BackgroundImage = (Bitmap)eventArgs.Frame.Clone();
with the following code:
Bitmap myImage = (Bitmap)eventArgs.Frame.Clone();
string strGrabFileName = String.Format("C:\\My_folder\\Snapshot_{0:yyyyMMdd_hhmmss.fff}.bmp", DateTime.Now);
myImage.Save(strGrabFileName, System.Drawing.Imaging.ImageFormat.Bmp);
and it works like a charm!
I'm developing a C# application with the Kinect, and I'd like to relay back to the user their reflection (with the RGB camera) or the skeletal view while they're using the application. Is that possible? Or is there a better way to show the user what the camera sees while running?
Thanks!
The Kinect for Windows Developer Toolkit has examples that do exactly this. There are multiple examples Demonstrating how to display the depth and color streams, as well as how to show the skeleton by it'll or overlayed on the video stream.
The "Kinect Explorer" example is the more advanced of those examples, showing how to put it all together.
I want to save the video streams that is captured by Kinect's Color camera to .avi format video, I tried many ways of doing this but nothing was succeeded. Has anyone successfully done this? I'm using Kinect for Windows SDK and WFP for application development
I guess the easiest workaround would be to use a screen capture software like http://camstudio.org/.
There is also post with the same question her:
Kinect recording a video in C# WPF
As far as I understand you need to to save the single frames delivered by the kinect by into a video file. This post should explain how to do it How to render video from raw frames in WPF?.
You can use the AVIFile Windows API using interop:
http://msdn.microsoft.com/en-us/library/windows/desktop/dd756808(v=vs.85).aspx
or you can use a wrapper like this one, done by Corina John
http://www.codeproject.com/Articles/7388/A-Simple-C-Wrapper-for-the-AviFile-Library
I have a Microsoft LifeCam HD-5000 webcams. According to AMCap, the camera outputs a MJPEG stream at 30fps at 720p. I want to capture each JPEG frame in a small application without doing any preview or decompression/transcoding to minimize CPU utilization to the minimum possible.
I'm a C# developer, but I'm new to DirectShow. Is there a simple way to capture the MJPEG stream frame by frame as its output from the camera in C#/.NET without decompressing it?
First of all, you might not need to use DirectShow to access your camera. Check out the OpenCV project, which has .net bindings available at opencvdotnet.
If you'd like to go the DirectShow route, then you'll need the .NET bindings, available at the directshownet project. I believe your best bet will be to create a filter graph that contains your webcam as a source filter, and a sample grabber as your destination filter. Documentation for the sample grabber is on MSDN. This will give you access to the raw data. You can also request a particular data format and use the DirectShow intelligent connect to fill in the filter graph with the right conversion filters.
That being said, I definitely recommend OpenCV over DirectShow. DirectShow is very general purpose, and probably does more than you need it to do. OpenCV can be used to quickly access your camera. Perhaps check out this stackoverflow question Webcam Usage in C# for some more information and answers.
With DirectShowNet, I could never access to a single frame and show it as Bitmap anywhere. In every project I just see converters, direct show to screen or streaming. How to capture the stream as single bitmap frames?
in the Directshow.net Download package, they have sample code and inside Capture there is a project DxSnap which connects to a webcam through directshow.net and snaps a picture from the stream. You can view it and use that as a starting place.