Lecture-15 - is a local maximum in a 12 by 12 overlapping...

Info iconThis preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Lecture-15 Quad Trees, Chain Code, Shape number & Moravec’s interest operator Quad Trees • Data structure to represent regions • Three types of nodes: gray, black and white • First generate the pyramid, then: • If type of pyramid is black or white then return else – Recursively find quad tree of SE quadrant – Recursively find quad tree of SW quadrant – Recursively find quad tree of NE quadrant – Recursively find quad tree of NW quadrant – Retrun
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Chain Code • A simple technique to represent a shape of boundary. • Each directed line segment is assigned a code. • Chain code is integer obtained by putting together the codes of all consecutive line segments. • Shape number is a normalized chain code, which is invariant to translation and rotation.
Background image of page 2
3
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 Moravec’s Interest Operator Algorithm • Compute four directional variances in horizontal, vertical, diagonal and anti- diagonal directions for each 4 by 4 window. • If the minimum of four directional variances
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 10
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 12
Background image of page 13
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: is a local maximum in a 12 by 12 overlapping neighborhood, then that widow (point) is interesting. 5 6 ∑∑ = = + + +-+ + = 3 2 2 )) , 1 ( ) , ( ( j i h j y i x P j y i x P V ∑∑ = = + + +-+ + = 2 3 2 )) 1 , ( ) , ( ( j i v j y i x P j y i x P V ∑∑ = = + + + +-+ + = 2 2 2 )) 1 , 1 ( ) , ( ( j i d j y i x P j y i x P V ∑∑ = = + +-+-+ + = 2 3 1 2 )) 1 , 1 ( ) , ( ( j i a j y i x P j y i x P V )) , ( ), , ( ), , ( ), , ( min( ) , ( y x V y x V y x V y x V y x V a d v h = = therwise local y x ifV y x I max ) , ( 1 ) , ( 7 Books by Hans Moravec • Robot Rover Visual Navigation • Mind Children: The future of Robot and Human Intelligence • Robot, Being – Website http://www.frc.ri.cmu.edu/~hpm/ 8 Cart under SAIL 1979 and 1997 3D Maps from stereo 9 NAVLABS Beast 10 Universal Delivery Potsdam 11 Home Vacuum Cleaning Robot (Dustbot) Home Vacuum Cleaning Robot (Dustbot) 12 13...
View Full Document

This note was uploaded on 06/12/2011 for the course CAP 5415 taught by Professor Staff during the Fall '08 term at University of Central Florida.

Page1 / 13

Lecture-15 - is a local maximum in a 12 by 12 overlapping...

This preview shows document pages 1 - 13. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online