I would like to test around a bit with augmented reality.How to get the picture that comes from the camera as background for my view? For what I want to do, I don't need to access the picture, I just need it as background.
You can get the preview-buffer from the camera from the page. We need this to capture a QR-Code without taking pictures with the camera.
Initialize the camera object
_phoneCamera = new PhotoCamera();
_phoneCamera.Initialized += CamInitialized;
In the Initialized - Event. Just create the buffer
private void CamInitialized(object sender, CameraOperationCompletedEventArgs e)
{
_previewBuffer = new WriteableBitmap((int)_phoneCamera.PreviewResolution.Width, (int) _phoneCamera.PreviewResolution.Height);
}
Ant then you can take everytime a snapshot of the current view:
//grab a camera snapshot
_phoneCamera.GetPreviewBufferArgb32(_previewBuffer.Pixels);
_previewBuffer.Invalidate();
And then you can do what you want with this WriteableBitmap (show as background, or whatever).
Or (if I misunderstood your question) here a link with the info, how to add the camera-view to your page (this is also needed for the above solution): How to create a base camera app for Windows Phone 8
Related
I am making use of the AForge class library.
From this library I am using VideoSourcePlayer to take photos with the webcam.
My purpose is to create a function that allows the user to photograph images to establish them as company logo.
Not only can you choose images from the computer, but you can also capture images from the outside through the camera, since you may only want to transfer a logo of a physical support (paper) to the program.
As commented earlier in SO, (how to pause a video file played using videosourceplayer), VideoSourcePlayer does not have a Pause method or any function that allows to freeze the image.
Yes, it is true that it has the GetCurrentFrame() method, but that only gets a Bitmap from the current frame that must be passed to a PictureBox.
But I want that when the user clicks the button Capture the image of the VideoSourcePlayer simulate being frozen, and when the user presses the Delete button because he did not like the photo, then the image stops being frozen and recovers its movement.
Logic is like pausing or playing a video.
Well, there's no method for it, so I decided to look for another way to get this, and ...
If a picture is taken, use a PictureBox that contains the last frame and that is displayed on the VideoSourcePlayer, but if it is deleted, then the PictureBox is removed and the VideoSourcePlayer is returned with video.
private readonly Bitmap EmptyBitmap;
private void CaptureBtn_Click(object sender, EventArgs e)
{
Bitmap bitmap = this.VideoSource.GetCurrentVideoFrame();
ShowTakedFrame(bitmap, false);
}
private void ShowTakedFrame(Bitmap Frame, bool remove)
{
var picture = new System.Windows.Forms.PictureBox();
picture.Size = this.VideoSource.Size;
picture.Location = this.VideoSource.Location;
if (!remove)
{
this.VideoSource.Stop();
picture.Image = Frame;
this.Controls.Remove(VideoSource);
this.Controls.Add(picture);
}
else
{
this.Controls.Remove(picture);
this.Controls.Add(VideoSource);
this.VideoSource.VideoSource = this.CaptureDevice;
this.VideoSource.Start();
}
}
private void DeleteBtn_Click(object sender, EventArgs e)
{
ShowTakedFrame(EmptyBitmap, true);
}
My problem is that when capturing the photo, the image is a few seconds after the moment when you press the Capture button and when you delete the captured image, using the Delete button, the video of the VideoSourcePlayer is frozen.
Can someone help me with this?
The problem is that when you remove the PictureBox and add the VideoSourcePlayer, it creates a new object, that is, one that does not have the configuration properties of the previous one. My recommendation is that you create the capture in a different form.
I have a WPF application which dynamically loads video or image files(depending on user's choice, to a MediaElement control.
It is working fine when it is a video and gets the MediaEnded event fired on ending the video.
But when I load an image, the MediaEndedevent is fired within 5 seconds.
Is it a default value? or can I change it programmatically?
Is there any property to change this interval or disable such an option?
Is it possible to make it paused until a specific action?
I have set the following properties as follows
MediaControl1.LoadedBehavior = MediaState.Manual;
MediaControl1.UnloadedBehavior = MediaState.Manual;
MediaElement is a (very thin) wrapper around Windows Media Player (or rather - uses the same framework which is used by Windows Media Player). If you open an image in Windows Media Player - you will see it will "play" it like a slideshow (even for 1 image), for about 5 seconds. That's why you get MediaEnded event in 5 seconds - Windows Media Player plays slideshow with your image for that duration. I doubt there is a way to change this from WPF (because it's behavior of external program\framework, not related to MediaElement itself) and I'm not aware of the way to change this for Windows Media Player (and even if there is such a way - it will have global effect and you probably don't want to modify your clients computer in such a way).
To solve your problem - just don't use MediaElement for displaying images - use something like Image control. If you have really strong reasons to do that - you can pause MediaElement with Pause method after your "slideshow" has been loaded, then it will not fire MediaEnded event. All in all - I cannot imagine any use case where you really have to use MediaElement for images.
You can repeat the media when you load image. Handle MediaEnded event like this:
void me_MediaEnded(object sender, EventArgs e)
{
//play video again
mediaElement.Position = new TimeSpan(0, 0, 1);
mediaElement.Play();
}
Additionally see this. It may help:
https://stackoverflow.com/a/3406857/5675763
I am developing a windows service which processes video input and sends results of interest to a separate platform. I do not need to display the frames in this context. I am having a problem getting the correct camera input.
I want to save a Bitmap resulting retrieved from am EMGU capture object. To make sure that the capture is actually reading the video stream, I save the bitmap to a file, as follows:
Mat frame = mCapture.QueryFrame();
Template = frame.Bitmap;
Template.Save("frozen.jpg");
The capture is initialized as follows:
CvInvoke.UseOpenCL = false;
int index = int.Parse(ConfigurationManager.AppSettings["Index"]);
mCapture = new Capture(index);
One test platform is a Lenovo laptop running 64-bit Windows 10, with a built-in camera and a second camera attached through a USB port. The input of interest is the second camera. However, whatever index I use to open the Capture object, the input comes from the built-in camera.
The other platform is a Meego Pad, running 32-bit Windows 10, with the same camera attached. In this case, I simply get blank frames as video input. For both platforms, running the camera application shows the video input as expected. What is the problem with my initialization of the Capture object?
Further Investigation Shows...
First, I was using the wrong index to create the capture, so that created some of the confusion. But more confusion follows.
When I call the QueryFrame() method in an event delegate, as shown in this simple example I successfully retrieve the frame from the camera. Example code looks like this:
Application.Idle += new EventHandler(delegate(object sender, EventArgs e)
{ //run this until application closed (close button click on image viewer)
viewer.Image = capture.QueryFrame(); //draw the image obtained from camera
});
viewer.ShowDialog(); //show the image viewer
When I call the same method in a different thread (in response to a communication event) I get an empty image. On the gripping hand, when I call the method in a timer callback, I get the correct image.
I won't call this closed, because I would still like to know why QueryFrame() acts correctly in some threads, but not in others. However, I can work with this, so the question is now mostly academic.
My app is supposed to take a photo, then stop there showing the photo, save it in a file and move on to another view.
I use the Microsoft.Devices.PhotoCamera and wait after a photo is taken for CaptureCompleted to take the image and for CaptureImageAvailable to store it and then move on.
Whan happens is: After a picture is taken, I get the camera preview again, which might be confusing for users (though a progress-bar is shown to tell them "wait pls". still not nice) and after 1-2 seconds it shows the taken picture again and moves on to the next view.
Is there a nice way to disable this preview-thing?
If I dispose the PhotoCamera after the first event, it hangs. If I dispose it after the 2nd event, it doesn't seem to make much difference..
Edit:
private void Cam_CaptureImageAvailable(object sender, Microsoft.Devices.ContentReadyEventArgs e)
{
this.imageStream = e.ImageStream;
Deployment.Current.Dispatcher.BeginInvoke(delegate
{
this.image = new BitmapImage();
this.image.SetSource(this.imageStream);
this.PreviewImage.Source = this.image;
// Part where I store the image into a file.
// Part where I navigate to the next view.
});
}
I need that Dispatcher-Thing because setting images and navigating needs the UI-thread but the method runs in a different one.
Also a strange point: it doesn't matter that the PreviewImage lies OVER the canvas with the camera-preview. It is still overwritten as soon as the picture is taken and being processed... ôo
The problem might be that I do many things and the UI is never refreshed. I could add a small sleep (1-5ms) but that would be async again. Also I can't do this completely serparated because the storing part makes a "screenshot" which should contain the final image instead of the camera-preview-thing.
Edit2:
I see the main problem in the capture itself. It takes a picture, shows it for a while, then switches to the camera preview and then back to my shown picture.
I am making an application that will allow users to apply certain tools to analyse videos & images. I need help with how i actaully draw/write on the video loaded into windows media player within my form and being able to save it on. It needs to be able to lert the user draw freehand and shapes on it.
Thanks in Advance,
Chris :)
This is a non-trivial, if not impossible task to accomplish with the wmp control in winforms.
I don't know of any way to actually draw on the wmp but you could draw on a transparent panel overlaid over the wmp. This will not work will the video is playing but you can show the drawing while it is paused. I have used this technique to draw over a 3rd party video control that works similarly to wmp.(Edit - this does not seem to work with the wmp control)
However, as real transparent panels are also rather tricky in winforms, another way would be to grab an image from the video and draw on the overlaid image. Again, only when it is paused.
This commercial control does enable drawing over the video. It has an event that fires every frame that you can use to do the drawing. The big downside, though is that you can't really do anything too fancy as your drawing routine needs to finish before the next frame is drawn.
I would strongly encourage you to use WPF(even if its a wpf control hosted within a winforms app) to show your video. It is a whole lot easier to draw on video(including playing video) in wpf.
EDIT
I just tested drawing over the wmp using a transparent panel and its doesn't behave as my 3rd party control did,so I suggest you do the video playing bit in WPF and host that in your winforms app. (I just tested that too using #Callums inkcanvas suggestion and it works like a charm)
If you are using WPF, try placing an InkCanvas on top of your video and setting the Background to transparent. You can then save and load up the shapes the users draw on top of the video.
A little proof-of-concept with a picture instead of a video:
I suspect you may be using WinForms though, where this may be more difficult. If so, a good excuse to learn WPF!
EDIT: With WinForms, you would have to make your own custom control that acts as a transparent overlay and add brush strokes to it. It would be extremely hard to implement well (with transparent background, which doesn't play well with
WinForms). I would recommend using WPF if you are still at a stage you can change your application's UI. WPF works on XP and up.
EDIT2: After googling, there are some InkCanvas equivalents that people have made for WinForms, but I have no idea how good they are and may not support transparent backgrounds.
You could always have the video that you want annotated in a new WPF window and the rest of your application in WinForms.
I have found how to do this.
Here is one way in WPF using Canvas
private void buttonPlayVideo_Click(object sender, RoutedEventArgs e)
{
Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
dlg.Filter = "All Files|*.*";
Nullable<bool> result = dlg.ShowDialog();
if (result == true) {
MediaPlayer mp = new MediaPlayer();
mp.Open(new Uri(filename));
VideoDrawing vd = new VideoDrawing();
vd.Player = mp;
vd.Rect = new Rect(0, 0, 960, 540);
DrawingBrush db = new DrawingBrush(vd);
canvas.Background = db;
mp.Play();
}
}
then create mouse events for Canvas and draw with it
Point startPoint, endPoint;
private void canvas_MouseDown(object sender, MouseButtonEventArgs e)
{
startPoint = e.GetPosition(canvas);
}
private void canvas_MouseUp(object sender, MouseButtonEventArgs e)
{
endPoint = e.GetPosition(canvas);
Line myLine = new Line();
myLine.Stroke = System.Windows.Media.Brushes.LightSteelBlue;
myLine.X1 = startPoint.X;
myLine.Y1 = startPoint.Y;
myLine.X2 = endPoint.X;
myLine.Y2 = endPoint.Y;
myLine.HorizontalAlignment = HorizontalAlignment.Left;
myLine.VerticalAlignment = VerticalAlignment.Center;
myLine.StrokeThickness = 2;
canvas.Children.Add(myLine);
}
This can be done in WinForms but it is not easy. There is transparent form support with alpha blending in WinForms. Use the following CreateParams for the transparent overlay form: WS_EX_LAYERED, WS_EX_TRANSPARENT. Check the MSDN references for this type of window: http://msdn.microsoft.com/en-us/library/ms997507.aspx, http://msdn.microsoft.com/en-us/library/ms632599%28VS.85%29.aspx#layered.
Put a transparent form above your video control and you can draw anything you want on it. Move and resize events need to be coordinated between your video window and the transparent form above it. Redrawing the overlay needs to use UpdateLayeredWindow() in user32.dll.
I learned quite a bit from this example: http://www.codeproject.com/Articles/13558/AlphaGradientPanel-an-extended-panel.
You might look at XNA (www.xna.com) from Microsoft. It is made for managed languages like c# and should support video.
I've only used it for drawing in c#, but it gets the job done.
I should also note that XNA will function as part of a regular Windows Forms app. For what it's worth, I have also prototyped something like this with Flash; Flash allows you to import each frame of the movie file into the editor and create a SWF that can respond to user interaction.
However, this approach is useless if you need to update the movie in real-time. Flash (last I checked) could only import the movie at design time.
Ok, by far and away the best way of doing this is to use Silverlight. Silverlight supports all of the major streaming formats and also provides complete access to the framebuffer.
Easy :-)