AJAX :: Image Control Not Updating In UpdatePanel?

I develop an ASP.NET web application. The server side receives a stream of image data (JPEG frames as byte arrays).

It should processes them and send the images to the client side periodically.

For displaying these images on the client side I tried to use an approach similar to this described in the post "Improve your Image(s)" (http://steveorr.net/articles ImproveYourImages.aspx) by using an auxiliary ASP.NET page for the purposes of the server side image processing.

When I used a client side button to request the image ocntrol (imgCameraCapture) update with its URL pointing to the processing page (GenImage.aspx, as in the above post), everything worked fine (with exception of the whole page re-rendering on each button event). The image was updated.

For a periodic update of the client image control on the main page I put in an ASP.NET AJAX UpdatePanel andset it to update conditionally by triggering to an ASP.Net AJAX timer (10 seconds) event in order to achieve a partial page update (just the image).

II used the timer tick event handler to update the image by invoking the separate ASP.NET image data processing page there as in the button click event handler. But in the timer tick event handler the processing page was not invoked and the image was not updated.

This is the C# code behind executed in the button clik and timer tick event handlers:

imgCameraCapture.ImageUrl = "~/GenImage.aspx";