Monday 19 January 2015

Simple Webcam Image

Here we'll go over the most bare bones simplest way to snap a image using your web cam. Firstly we have to add the capability in your application. Open up you Package.appxmanifest file and go to the the Capabilities tab, there check off the Webcam capability.

with that done open up your MainPage.xaml file and we're going to build our UI, pretty straight forward just a button with an image.


    <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
        <StackPanel Orientation="Horizontal">
            <Button x:Name="CapturePhoto_BTN" Content="Capture Photo"/>
            <Image x:Name="Image_IMG" Height="900" />

Ok now let's jump into the codebehind MainPage.xaml.cs, here's where the heavy lifting happens. Firstly what we have to do is create a event handler for our button.

using System;
using Windows.Media.Capture;
using Windows.Storage;
using Windows.UI.Popups;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Media.Imaging;

namespace pc.Media
    public sealed partial class MainPage : Page
        public MainPage()
            this.CapturePhoto_BTN.Click += CapturePhoto_BTN_Click;

        async void CapturePhoto_BTN_Click(object sender, RoutedEventArgs e)
           throw new NotImplementedException();

what we did was added the CapturePhoto_BTN_Click event handler to the click event of the CapturePhoto_BTN click event. Now let's add our Photo logic.

async void CapturePhoto_BTN_Click(object sender, RoutedEventArgs e)
    var camera = new CameraCaptureUI();

    //wait for the image
    StorageFile img = await camera.CaptureFileAsync(CameraCaptureUIMode.Photo);

    //Check if it was sent back
    if (img != null)
        var bitmap = new BitmapImage();

        //translate the stream to an image
        bitmap.SetSource(await img.OpenAsync(FileAccessMode.Read));

        //set the UI E
        this.Image_IMG.Source = bitmap;
        await new MessageDialog("No Photo recieved").ShowAsync();


notice that we changed our event handler to be asynchronous, with that complete we can now take pictures, the thing to take note of is we're not actually taking the picture, what we're doing is passing off the image capture to the CameraCaptureUI which is taking the image on our behalf and then passes back a StorageFile to our application.

as you see above, this is not our UI, and yes i realize my webcam is broken.