I incorporated Hough Transform component and Object Tracking component (Camshift). What I made is a hybrid object tracking system of shelf-detection and Camshift.
Shelf-detection component sends Camshift component camera displacement data observed, and Camshift component tracks the item, using the data for setting an initial region to search the item.
And then, shelf-detection component start the observation of the shelf near the item location tracked by Camshift component.
Here is a screen shot of the software. In this case, "Pocky"(Japanese famous chocolate cookie) is the target.
Unfortunately, the result was a disappointing one. The shelf-detection isn't accurate enough to track the object effectively, while Camshift component is working well.
I wonder if I should give up using Hough Transform for shelf-detection...