A Hybrid Method for Endocardial Contour Extraction of Right Ventricle in 4-Slices from 3D Echocardiography Dataset

Algorithm 2

Improved radial search method.

(1) Input: Binary-threshold Image, S

(2) Intput: Maximum Distances,

(3) Output: Processed Image,   / *  The extracted contour of RV endocardial  */

(4)     /*  Call the radial search procedure based on maximum */

(5)      /* distance for each part of RV cavity */

(6) 

(7) 

(8) Procedure Radial_search (, , D _max) /* Start implementation of improved radial-search  */

(9) Begin

(10)   For  ← to       /* iterative circle scanning loop  */

(11)    Begin

(12)     

(13)        /*  where,   and    are the contour coordinates  */

(14)      + )   /*   =1 is the initial value of radius length  */

(15)      nL ←  : I ←: ←   /*  where is the new value of raduis length  */

(16)   While  ((, ) 255) and ( < D _max)   /*  Repeat loop until the contour pixel is found  */

(17)    Begin            /*  the value of which is equal to 255  */

(18)      (, ) ← 0: ← + 1    /*  or reaching the maximum distance  */

(19)          /*  otherwise increase the by 1  */

(20)      )

(21)      ←  :  ←

(22)   end_while

(23)     ← ←    /* Save coordinates of border points in two scalars  */

(24)   end_for

(25) Return (), ()