Zhang-Suen thinning algorithm: Difference between revisions

<lang elena>#import system'collections.

#import system'routines.

#import extensions.

#import extensions'routines.

#subjecttype charmatrix = matrixof(char)matrix<CharValue>.

extension(charmatrix) extension zhangsuenOp

if (self@[r@][c] != #$35)

int nn := self numNeighbors:(r:,c).

if(self numTransitions:(r:,c) != 1)

ifnot (self atLeastOneIsWhite:(r:,c:(,firstStep iif:(0:,1)))

toWhite += append:{ x = c. y = r. }.

0 till:(nbrs length - 1) &doEach:do(:i)

if (self@([r + nbrs@[i@][1)@(]][c + nbrs@[i@][0)]] == #$35)

0 till:(nbrs length - 1) &doEach:do(:i)

if (self@([r + nbrs@[i@][1)@(]][c + nbrs@[i@][0)]] == #$32)

if (self@([r + nbrs@([i + 1)@][1)@(]][c + nbrs@([i + 1)@][0)]] == #$35)

var group := nbrGroups@[step].

0 till:2 &doEach:do(:i)

0 till:(group@[i] length) &seekEach:seek(:j)

var nbr := nbrs@([group@[i@][j)]].

if (self@([r + nbr@[1)@(]][c + nbr@[0)]] == #$32)

[ count := count + 1. ^ true. ].

1 till:(self rows - 1) &doEach:do(:r)

1 till:(self columns - 1) &doEach:do(:c)

if (self~zhangsuenOp $proceed:(r:,c:,toWhite:,firstStep))

toWhite run &each:forEach(:p)[ self@([p y)@(][p x)] := #$32. ].

it run &each:forEach(:ch) [ console writeLiteral:print(ch:," ".) ].

it run &each:forEach(:ch) [ console writeLiteral:print(ch:," ".) ].

charmatrix grid := MatrixSpace::

columns = image@[0] length.

getAt &int:i &int:j

= image@[i@][j].