00100	CS 224    	Handout #8
00200	May 21,1974   
00300	
00400	
00500	Administrative 
00600	_____________
00700	
00800	There will be no final exam. The course grade is based solely upon
00900	homework assignments.  Therefore we urge you to turn in all homeworks.
01000	They will be accepted with no penalty for lateness; all homeworks must
01100	be in by June 10, however.
01200	
01300	
01400	
01500	Homework # 7
01600	____________
01700	
01800	Due Tuesday, May 28, 1974
01900	
02000	
02100	Do Problem 1, and do one of Problems 2 and 3. Note that problem 3
02200	is much more difficult -- and much more interesting -- than #2.
02300	
02400	1) The following statements each embody an idea relevant to an AI
02500	vision system.  For each one, state whether Falk's system embodies
02600	this idea, and if so, where. Discuss how the idea could be useful
02700	in dealing with Blocks World scenes. Optional: discuss situations
02800	in which the idea would hinder correct scene analysis.
02900	
     

00100	2) Although Falk's system is better than Guzman's, it still can be
00200	misled. Draw a Blocks World scene which Falk's program would mis-
00300	identify. Explain why this happens. Optional: how could this error
00400	be handled; e.g., would a shift to a new viewing position solve the
00500	problem?
00600	
00700	3) Falk took Guzman's system and modified it so that it could deal
00800	effectively with imperfect line drawings.  Waltz's system (described
00900	in the Winston section of the 224 Classnotes) is very elegant, but
01000	collapses if the input drawing is not perfect.  Your task is to complete
01100	the analogy    Guzman:Falk :: Waltz: ?
01200	That is, how could Waltz's work be extended to deal with real-life
01300	Blocks World scenes, where some lines are missing and some spurious
01400	ones are present?