Efficient object contour tracing in a quadtree encoded image

G. N. Kumar; Nagaraj Nandhakumar

doi:10.1117/12.45527

1 March 1991 Efficient object contour tracing in a quadtree encoded image

G. N. Kumar, Nagaraj Nandhakumar

Proceedings Volume 1468, Applications of Artificial Intelligence IX; (1991) https://doi.org/10.1117/12.45527
Event: Orlando '91, 1991, Orlando, FL, United States

Abstract

A new algorithm is presented to extract the chain-code representation of the boundary of a binary image. The quadtree representation of this image acts as the input to the algorithm. This algorithm is more efficient than the previously reported algorithm. The algorithm can trace the boundary according to either eight-connected or four-connected neighborhood definitions without any modification. The boundary is traced in the clock-wise direction with respect to the object. The algorithm is based on the following two observations; (1) Visiting a sequence of four-connected white nodes that lie along the object boundary yields an eight-connected boundary while (2) visiting a sequence of four-connected black nodes that lie along the object boundary yields a four-connected boundary. In other words, tracing the object boundary from outside the object using four-connected neighborhood definition extracts an eight-connected boundary, and tracing the object boundary from within the object using four-connected neighborhood definition extracts a four-connected boundary.

Citation Download Citation

G. N. Kumar and Nagaraj Nandhakumar "Efficient object contour tracing in a quadtree encoded image", Proc. SPIE 1468, Applications of Artificial Intelligence IX, (1 March 1991); https://doi.org/10.1117/12.45527

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available