Zhang Suen Algorithm

[julianluthor]

i'm trying to use Zhang Suen thinning algorithm to thin my image but the result is the same before i use the thinning algorithm.can somebody help?

void __fastcall TForm1::Button2Click(TObject *Sender) 
{ 
//THINNING 
int count,count2,x,y; 
int num_transitions ; 
int transitions ; 
int tempimage[400][400]; 
int x1,y1; 
int DataWidth = Image1->Picture->Width; 
int DataHeight = Image1->Picture->Height; 
for(x = 1; x < DataHeight-1 ; x++) 

{ 

for(y = 1; y < DataWidth-1 ; y++) 

{ 

count = 0; 

num_transitions = 0; 

// check for N(p) 

if ((Byte)Image1->Canvas->Pixels[y][x] == 255) 

{ 

if ((Byte)Image1->Canvas->Pixels[y-1][x-1] != 0) 

count++; 

if ((Byte)Image1->Canvas->Pixels[y][x-1] != 0) 

count++; 

if ((Byte)Image1->Canvas->Pixels[y+1][x-1] != 0) 

count++; 

if ((Byte)Image1->Canvas->Pixels[y+1][x] != 0) 

count++; 

if ((Byte)Image1->Canvas->Pixels[y-1][x] != 0) 

count++; 

if ((Byte)Image1->Canvas->Pixels[y+1][x+1] != 0) 

count++; 

if ((Byte)Image1->Canvas->Pixels[y][x+1] != 0) 

count++; 

if ((Byte)Image1->Canvas->Pixels[y-1][x+1] != 0) 

count++; 

if (count != 8) 

{ 

// 2 <= N(p) <= 6 

if (count >= 2 && count <= 6) 

{ 

if((Byte)Image1->Canvas->Pixels[y-1][x] == 0 && 

(Byte)Image1->Canvas->Pixels[y-1][x+1] == 255) 

num_transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y-1][x+1] == 0 && 

(Byte)Image1->Canvas->Pixels[y][x+1] == 255) 

num_transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y][x+1] == 0 && 

(Byte)Image1->Canvas->Pixels[y+1][x+1] == 255) 

num_transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y+1][x+1] == 0 && 

(Byte)Image1->Canvas->Pixels[y+1][x] == 255) 

num_transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y+1][x] == 0 && 

(Byte)Image1->Canvas->Pixels[y+1][x-1] == 255) 

num_transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y+1][x-1] == 0 && 

(Byte)Image1->Canvas->Pixels[y][x-1] == 255) 

num_transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y][x-1] == 0 && 

(Byte)Image1->Canvas->Pixels[y-1][x-1] == 255) 

num_transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y-1][x-1] == 0 && 

(Byte)Image1->Canvas->Pixels[y-1][x] == 255) 

num_transitions++ ; 

//S(p) = 1 

if (num_transitions == 1) 

{ 

// if p2 * p4 * p6 = 0 

if((Byte)Image1->Canvas->Pixels[y-1][x] == 0 || 

(Byte)Image1->Canvas->Pixels[y][x+1] == 0 || 

(Byte)Image1->Canvas->Pixels[y+1][x] == 0) 

{ 

// if p4 * p6 * p8 = 0 

if((Byte)Image1->Canvas->Pixels[y][x+1] == 0 || 

(Byte)Image1->Canvas->Pixels[y+1][x] == 0 || 

(Byte)Image1->Canvas->Pixels[y][x-1] == 0) 

tempimage[y][x] = 0; 

else 

tempimage[y][x] = 255; 

} 

else 

tempimage[y][x] = 255; 

} 

else 

tempimage[y][x] = 255; 

} 

else 

tempimage[y][x] = 255; 

} 

else 

tempimage[y][x] = 255; 

} 

else 

tempimage[y][x] =0;//255; 

} 

} 

//copy thinned image back to original 

for(x = 0; x < DataHeight ; x++) 

for(y = 0; y < DataWidth; y++) 

tempimage[y][x]=(Byte)Image1->Canvas->Pixels[y][x]; 

// step 2 of the thinning algorithm 

for(x1 = 1; x1 < DataHeight-1 ; x1++) 

{ 

for(y1 = 1; y1 < DataWidth-1 ; y1++) 

{ 

count2 = 0; 

transitions = 0; 

if ((Byte)Image1->Canvas->Pixels[y1][x1] == 255) 

{ 

if ((Byte)Image1->Canvas->Pixels[y1-1][x1-1] != 0) 

count2++; 

if ((Byte)Image1->Canvas->Pixels[y1][x1-1] != 0) 

count2++; 

if ((Byte)Image1->Canvas->Pixels[y1+1][x1-1] != 0) 

count2++; 

if ((Byte)Image1->Canvas->Pixels[y1+1][x1] != 0) 

count2++; 

if ((Byte)Image1->Canvas->Pixels[y1-1][x1] != 0) 

count2++; 

if ((Byte)Image1->Canvas->Pixels[y1+1][x1+1] != 0) 

count2++; 

if ((Byte)Image1->Canvas->Pixels[y1][x1+1] != 0) 

count2++; 

if ((Byte)Image1->Canvas->Pixels[y1-1][x1+1] != 0) 

count2++; 

if (count2 != 8) 

{ 

if (count2 >= 2 && count2 <= 6) 

{ 

if((Byte)Image1->Canvas->Pixels[y1-1][x1] == 0 && 

(Byte)Image1->Canvas->Pixels[y1-1][x1+1] == 255) 

transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y1-1][x1+1] == 0 && 

(Byte)Image1->Canvas->Pixels[y1][x1+1] == 255) 

transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y1][x1+1] == 0 && 

(Byte)Image1->Canvas->Pixels[y1+1][x1+1] == 255) 

transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y1+1][x1+1] == 0 && 

(Byte)Image1->Canvas->Pixels[y1+1][x1] == 255) 

transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y1+1][x1] == 0 && 

(Byte)Image1->Canvas->Pixels[y1+1][x1-1] == 255) 

transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y1+1][x1-1] == 0 && 

(Byte)Image1->Canvas->Pixels[y1][x1-1] == 255) 

transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y1][x1-1] == 0 && 

(Byte)Image1->Canvas->Pixels[y1-1][x1-1] == 255) 

transitions++ ; 

if((Byte)Image1->Canvas->Pixels[y1-1][x1-1] == 0 && 

(Byte)Image1->Canvas->Pixels[y1-1][x1] == 255) 

transitions++ ; 

if (transitions == 1) 

{ 

// if p2 * p4 * p8 = 0 

if((Byte)Image1->Canvas->Pixels[y1-1][x1] == 0 || 

(Byte)Image1->Canvas->Pixels[y1][x1+1] == 0 || 

(Byte)Image1->Canvas->Pixels[y1][x1-1] == 0) 

{ 

// if p2 * p4 * p6 

if((Byte)Image1->Canvas->Pixels[y1-1][x1] == 0 || 

(Byte)Image1->Canvas->Pixels[y1+1][x1] == 0 || 

(Byte)Image1->Canvas->Pixels[y1][x1-1] == 0) 

tempimage[y1][x1] = 0; 

else 

tempimage[y1][x1] = 255; 

} 

else 

tempimage[y1][x1] = 255; 

} 

else 

tempimage[y1][x1] = 255; 

} 

else 

tempimage[y1][x1] = 255; 

} 

else 

tempimage[y1][x1] = 255; 

} 

else 

tempimage[y1][x1] = 0; 

} 
} 

for(x1 = 0; x1 < DataHeight ; x1++) 

for(y1 = 0; y1 < DataWidth; y1++) 

tempimage[y1][x1]=(Byte)Image1->Canvas->Pixels[y1][x1]; 

tempimage[y][x] = tempimage[y1][x1]; 

TStringList* papar = new TStringList; 

AnsiString str_line; 

for(int j=0; j<400; j++) 

{ 

str_line = &quot;&quot;; 

for(int i=0; i<400; i++) 

{ 

if(i) 

str_line += &quot;, &quot;; 

Data[i][j]= (Byte)Image1->Canvas->Pixels[i][j]; 

if (Data[i][j]>127) 

{ 

Data[i][j] = 0; 

} 

else 

{ 

Data[i][j] = 1; 

} 

str_line += IntToStr(Data[i][j]); 

} 

papar->Add(str_line); 

} 

papar->SaveToFile(&quot;Julian.dat&quot;); 

delete papar; 

}

 

[Totte]

What 'thinning' is it that you want?

Totte