[IGSTK-Developers] Continuting the discussion on error handling methods....

[Andinet Enquobahrie]

Dear all

I am putting the final touches on the LandMarkRegistration and 
ImageReader classes implementation for iteration 6. The main loose end I 
need to tighten up is error handling. Although we have brainstormed 
several options for error handling , we haven't yet reached a consensus.  

If you would like to refresh your mind on this topic,  please refer to 
the wiki page that David put together.

http://public.kitware.com/IGSTKWIKI/index.php/Error_Handling#Kinds_of_Errors 


For my specific needs, I am planning to implement event observers for 
recoverable error conditions in landmark registration and image reading.

The recoverable error conditions that I am anticipating are the following.

For LandMarkRegistration class

1) A request for transform computation before "enough" number of 
landmarks are established.

2) Incorrect order of landmark establishment.  I am enforcing a specific 
order of landmark establishment i.e  image followed by tracker 
coordinate for landmarks 1,2,3 (We are using 3D Rigid body transform)  
For example, an error condition arises if the application sets image 
coordinates of two landmarks successively without setting the tracker 
coordinate of the first landmark.

For ImageReader classes

1) An image read request before specifying the image file name.
2) Error during image reading operation (may be corrupted image data, 
invalid image format etc..)

This is not an exhaustive list by any means. But I believe these are the 
major ones.

I would like to get your comments/thoughts/suggestions on

- additional major error conditions and
- my pick of an error handing method

thanks

-Andinet