Zhang-Suen thinning algorithm: Difference between revisions

<lang ruby>

# Thinning RC

# Nigel_Galloway: October 18th., 2013.

s2 = [[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],

[0,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0],

[0,1,1,1,0,0,0,1,1,1,1,0,0,0,0,0,1,1,1,1,0,0,1,1,1,1,0,0,0,0,0,0],

[0,1,1,1,0,0,0,0,1,1,1,0,0,0,0,0,1,1,1,0,0,0,0,1,1,1,0,0,0,0,0,0],

[0,1,1,1,0,0,0,1,1,1,1,0,0,0,0,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0],

[0,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0],

[0,1,1,1,0,1,1,1,1,0,0,0,0,0,0,0,1,1,1,0,0,0,0,1,1,1,0,0,0,0,0,0],

[0,1,1,1,0,0,1,1,1,1,0,0,1,1,1,0,1,1,1,1,0,0,1,1,1,1,0,1,1,1,0,0],

[0,1,1,1,0,0,0,1,1,1,1,0,1,1,1,0,0,1,1,1,1,1,1,1,1,0,0,1,1,1,0,0],

[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]];

@r = 1

def zs(ng,g)

return 0 if ng[1][1] == 0 or (ng[1][2] + ng[0][1] + ng[1+g][g]) == 3 or (ng[g][1+g] + ng[2][1] + ng[1][0]) == 3

t = -1; ng.each{|n| n.each{|g| t+=g}}; return 0 unless (2 <= t and t <= 6)

t = -1; [ng[0][1],ng[0][2],ng[1][2],ng[2][2],ng[2][1],ng[2][0],ng[1][0],ng[0][0],ng[0][1]].each{|n|

if n==0 then t += (t==0 or t==2)? 0 : 1 else t += (t==0 or t==2)? 1 : 0 end}

return 0 unless t==1 or t==2

return @r=1

end

s2.each{|row| row.each{|col| print(col==1? "#": " ")}; print("\n")}

while @r == 1

@r = 0

s1 = Array.new(s2.length){Array.new(s2[0].length,0)}

(1...s2.length-1).each{|n| (1...s2[0].length-1).each{|g| s1[n][g] = s2[n][g] - zs(s2[n-1..n+1].collect{|n| n[g-1..g+1]},0)}}

s2 = Array.new(s1.length){Array.new(s1[0].length,0)}

(1...s2.length-1).each{|n| (1...s2[0].length-1).each{|g| s2[n][g] = s1[n][g] - zs(s1[n-1..n+1].collect{|n| n[g-1..g+1]},1)}}

end

s2.each{|row| row.each{|col| print(col==1? "#": " ")}; print("\n")}

</lang>

{{out}}

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