Read the chapter in the doc on creating custom components. You might be
better off extending mx:Image instead of SpriteVisualElement.
Thank you Flex harUI for your reply. Would you be kind enough to post the link to the doc?
Sorry for the late reply. Eventually I was able to get the image to load. Here is the initApp() function that successfully loads the image. The code posted at the beginning of the thread remains the same.
// entry point
private function initApp():void
var u:UIComponent = new UIComponent();
var im:ImageManipulation = new ImageManipulation();
Hope this helps.