A brief literature review follows. This is more of a topic reference for myself, than an in-depth discussion of the paper itself. 
 
REAL-TIME LENS DISTORTION CORRECTION: 3D VIDEO GRAPHICS CARDS ARE GOOD FOR MORE THAN GAMES 
Michael R. Bax 
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Bax discusses a method of using a GPU based approach for rapidly compensating for lens distortion using polar transformations. Bax's method differs from other methods I have seen in that it does not use a Cartesian based grid. Instead, this method uses a polar based system of concentric bands of triangles. These triangles represent the component parts of a surface over which the distorted image is texture mapped. The warped surface produced a counter-distorting effect which effectively straightens the distortion in the image. Bax's research showed that this polar based method is actually 50% more effective in error reduction than a standard grid based method. It was also found that this procedure could take place in real-time, providing a frame rate of at least 30 fps. 
 
Side Note: In a recent experiment we did here in the AR lab, we used a grid based approach to resolving lens distortion in a Sony Glasstron binocular, non-stereo HMD. However, the polar based method described in Bax's paper would not have been sufficient in our case due to additional, non-uniform distortion introduced by a set of plastic anaglyph filters placed on the HMD's oculi to enable stereo vision. Instead, we used the Cartesian grid based method. This method produced sufficient error reduction and allowed more fine grained (though very time consuming) distortion correction. 

Posted by: Adam Jones

A brief literature review follows. This is more of a topic reference for myself, than an in-depth discussion of the paper itself. 
 
RECENT ADVANCES IN AUGMENTED REALITY 
R. Azuma, Y. Baillot, R. Behringer, S. Feiner, S. Julier, B. MacIntyre 
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Azuma et.al. present an interesting survey of the state of AR technology, its recent advances, and its limitations in this paper from 2001. They provide a useful overview of topics including tracking, registration, usability, and interaction. An excellent break down of the different levels of virtual reality and augmented reality is presented as well. Various AR methods are also mentioned. These range from head worn displays to retro-reflective projection based systems. Current and potential applications for AR are also given. Some examples include military planning, simulation, navigation, factory work, construction, medical procedures, advertising, and entertainment. A brief discussion of environmental sensing is also included. This is an interesting topic, especially for unprepared environments, such as the outdoors. Indoor tracking in a prepared environment is easier but still a non-trivial task. Some techniques discussed exploit characteristics of particular locations, such as pipes and conduits running along walls and ceilings in a factory. The issue of “social acceptance” is also discussed as being a little addressed but highly influential factor in determining the future of AR among the general population. 

Posted by: Adam Jones

Hello there. I'm a Graduate Research Assistant for Dr. J. Edward Swan. I'm researching the nifty field of Augmented Reality (AR). 
 
Specifically, I'm currently working with Dr. Swan on understanding how people perceive depth in augmented environments. This is an interesting problem that fundamentally effects one's perception of mixed environments, containing both virtual and real-world objects. Current knowledge suggests that combinations of various depth cues result in stable depth perception. 
 
However, this problem becomes even more interesting when one considers that the salience of these depth cues changes depending given circumstances; such as distance, position, environmental conditions, etc... Also, utilizing AR in certain tasks can result in novel situations where depth resolution may be ambiguous because the given situation cannot exist under normal circumstances. A good example of this is x-ray vision. In this situation, individuals are allowed to see through or within objects that would occlude normal vision. 
 
Needless to say, this is a very interesting field and I consider myself quite lucky to be participating in this research. 
 
On a more personal note, I’m from a small community in Mississippi called Calhoun, which is just out side of the city of Laurel. I received my Associates degree in Computer Science from Jones County Junior College in 2002. I completed my Bachelor of Science degree at Mississippi State University in 2004 where I majored in Computer Science with a minor in Software Engineering. Now I am pursuing my Masters degree in the field of Graphics/Visualization. 

Posted by: Adam Jones