for
when the borders in the image posses higher rate to
whole image, this method will be clumsy. As a
result, we develop a new parallel algorithm;
(1). For a digital image f, translate f for a pixel
distance in E, S, W, and N directions,
respectively, and then obtain a fmaw ( i —
Be... 4)
(2). For fran» take the logical negation operation,
and then get feu (i=1,... ,4).
(3). Holding the logical disjunction opreation to fai,
obtain fpn.
(4). Operating f and fay With logical conjuntion ,
finally get the borders.
Obviously, this method is very efficient to be
performed in parallel array processors. Its diagram is
also simple(fig. 3).
Fig. 3 Block Diagram for Border Following
Fig. 4 is provided as a experimental result for border
following.
13
Fig. 4 a). The Original Binary Image.
b). The Border Image Found
by Border Following
4. REGION GROWING AND
MATRIX REPRESENTATION
A common image processing task is to separate out a
particular region of the overall image on the basis of
gray value or texture. The image is segmented into a
feature region and a background region. The steps
about region growing have been described previously.
Meanwhile, the proceduce is proved to be
connectivity — preserving. Several new operations
should be introduced, before presenting the block
diagram of GROW.
CTHRESH(£;,t)) (1,3)
( , if the grav value=t at(i,j)
0, otherwise
Unless f(i,j) is undefined, in which case CABS(f))
(ij x.
(DIV(f)I G,j)
FG” if f(1,j) is real and not
= ,
x, elsewhere