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Dynamic Webcam Image

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24 Jun 20021 min read 552.1K   18.3K   126   123
Streaming Dynamic Images from your webcam into your web pages.

Contents

Introduction

This project presents the way to dynamically generate a picture with C# and ASP.NET. Basically a browser points to your page and gets back a picture grabbed on your webcam.

You will be able to access your webcam by placing a HTML IMG tag on your webpage. The picture at the top is an example of usage.

To be able to use the webcam you need to register with regsvr32 the COM Dll CamServer.dll in the 'COM Component' directory.

Method

The first thing to do to get a picture from an ASP.NET page is to determine the MIME file type that the file will handle. In our case the MIME type is JPEG. So we define in the ContentType of the Page:

<%@ Page Language="c#" ContentType="image/jpeg" %>
We also need to specify at the top of the page the namespace that will be used:
C#
<%@ Import Namespace="System" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Drawing" %>
<%@ Import Namespace="System.Drawing.Drawing2D" %>
<%@ Import Namespace="System.Drawing.Imaging" %>
<%@ Import Namespace="System.Net" %>
Then comes the code that will grab the image from the wbecam and returns it to the client:
C#
<script language="C#" runat="server">

protected void Page_Load(object sender, EventArgs e)
{
    //Jpeg compression quality
    short nQuality = 45;

    //Shout a picture from my webcam
    CAMSERVERLib.Camera cam = new CAMSERVERLib.CameraClass();

    byte[] picture = (byte[])cam.GrabFrame( nQuality );

    //Add the hour to the jpeg picture
    MemoryStream ms = new MemoryStream( picture );
    Bitmap bmp = new Bitmap( ms );

    Graphics g = Graphics.FromImage( bmp );

    string strDate = DateTime.Now.ToLongDateString() + " - " + 
                                       DateTime.Now.ToLongTimeString(); 

	StringFormat drawFormat = new StringFormat();
    drawFormat.Alignment = StringAlignment.Center;

    g.DrawString(   strDate,
                    new Font( FontFamily.GenericSansSerif, 12 ),
                    new SolidBrush( Color.Black ), 
                    new RectangleF( 1,1,320,240 ),
                    drawFormat
                );

    g.DrawString(   strDate,
                    new Font( FontFamily.GenericSansSerif, 12 ),
                    new SolidBrush( Color.White ), 
                    new RectangleF( 0,0,320,240 ),
                    drawFormat
                );

    //Get codecs
    ImageCodecInfo[] icf = ImageCodecInfo.GetImageEncoders();

    EncoderParameters encps = new EncoderParameters( 1 );
    EncoderParameter encp = new EncoderParameter( System.Drawing.Imaging.Encoder.Quality, 
                                                  (long) nQuality );

    //Set quality
    encps.Param[0] = encp;

    bmp.Save( Response.OutputStream, icf[1], encps );
    
    g.Dispose();
    bmp.Dispose();
}
</script>
In the code there is nothing new, compared to the other articles. We get a jpeg picture grabbed by the webcam using COM Interop. We add the hour and the little difference is that the image stream is saved to Response.OutputStream .

Usage

You may reference the ASP.NET page has a normal jpeg picture:

HTML
<img src="http://XXX/WebcamPicture/WebForm1.aspx" width="320" height="240"/>
or in a ASP:Image control.

Conclusion

This opens lots of possibilities in the creation of dynamic graphics. For example you may create dynamic charts linked to database values returned has a normal graphic in a presentation page. You may also make easily a visit counter for your pages...

Known Issues

  • None.

History

Version 1.00 June 14, 2002
First release.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here


Written By
Team Leader
France France
I am an experienced Team Leader & Senior Solutions Architect with a passion for shipping high-quality products by empowering development team and culture toward an agile mindset. I bring technical vision and strategy, leading engineering teams to move product, processes and architecture forward.

Comments and Discussions

 
AnswerRe: How to show my picture in my Webcam on ASP.NET Pin
nida baber24-Sep-06 15:27
nida baber24-Sep-06 15:27 
GeneralCapture nothing ! Pin
hktang5-Jul-04 21:24
hktang5-Jul-04 21:24 
GeneralRe: Capture nothing ! Pin
dogpile22-Nov-08 17:27
dogpile22-Nov-08 17:27 
QuestionHow to show live video instead of a bmp Pin
victorlyons26-May-04 11:49
victorlyons26-May-04 11:49 
QuestionMultiple Cameras? Pin
BPSchwind29-Feb-04 10:43
sussBPSchwind29-Feb-04 10:43 
AnswerRe: Multiple Cameras? Pin
Nicklasson9-Mar-05 22:22
Nicklasson9-Mar-05 22:22 
Generalvery dark picture Pin
carlito punk25-Nov-03 20:33
carlito punk25-Nov-03 20:33 
Generalvb.net translation Pin
ramiroescobar10-Sep-03 7:46
ramiroescobar10-Sep-03 7:46 
GeneralRe: vb.net translation Pin
matrics2316-Sep-03 22:16
matrics2316-Sep-03 22:16 
GeneralRe: vb.net translation Pin
Dream2be5-May-05 4:02
Dream2be5-May-05 4:02 
GeneralRe: vb.net translation Pin
ganeshnet27-Apr-06 18:57
ganeshnet27-Apr-06 18:57 
GeneralRe: vb.net translation Pin
ganeshnet27-Apr-06 18:59
ganeshnet27-Apr-06 18:59 
GeneralNice job! Pin
Scott Burgett6-Aug-03 3:36
Scott Burgett6-Aug-03 3:36 
GeneralRe: Nice job! Pin
Laurent Kempé6-Aug-03 11:16
Laurent Kempé6-Aug-03 11:16 
GeneralRe: Nice job! Pin
Anonymous7-Aug-03 2:59
Anonymous7-Aug-03 2:59 
GeneralRe: Nice job! Pin
ECUMaster22-Jan-04 10:17
ECUMaster22-Jan-04 10:17 
GeneralProblem on page access Pin
carlito punk31-May-03 16:28
carlito punk31-May-03 16:28 
GeneralRe: Problem on page access Pin
Laurent Kempé31-May-03 22:14
Laurent Kempé31-May-03 22:14 
GeneralRe: Problem on page access Pin
carlito punk1-Jun-03 6:20
carlito punk1-Jun-03 6:20 
GeneralRe: Problem on page access Pin
carlito punk1-Jun-03 11:58
carlito punk1-Jun-03 11:58 
GeneralRe: GREAT!!! Pin
Laurent Kempé1-Jun-03 18:40
Laurent Kempé1-Jun-03 18:40 
GeneralRe: GREAT!!! Pin
manuelx7-Aug-03 3:02
manuelx7-Aug-03 3:02 
Generalgreat :) Pin
timx29-May-03 8:32
timx29-May-03 8:32 
GeneralRe: great :) Pin
Laurent Kempé29-May-03 20:13
Laurent Kempé29-May-03 20:13 
Questionhow can I use the dll from a c# class? Pin
Loski23-May-03 2:00
Loski23-May-03 2:00 

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