Zhang-Suen thinning algorithm: Difference between revisions

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Line 111: {{trans\|Python}} <~~lang~~syntaxhighlight lang="11l">V beforeTxt = \|‘1100111 1100111 ~~‘1100111~~ 1100111 1100111 1100110 ~~1100111~~ 1100110 1100110 1100110 1100110 1100110 1100110 1100110 1111110 ~~1100110~~ 0000000’ ~~1111110~~ ~~0000000’~~ V smallrc01 = \|‘00000000000000000000000000000000 01111111110000000111111110000000 01110001111000001111001111000000 01110000111000001110000111000000 01110001111000001110000000000000 01111111110000001110000000000000 01110111100000001110000111000000 01110011110011101111001111011100 01110001111011100111111110011100 00000000000000000000000000000000’ V rc01 = \|‘00000000000000000000000000000000000000000000000000000000000 01111111111111111100000000000000000001111111111111000000000 01111111111111111110000000000000001111111111111111000000000 01111111111111111111000000000000111111111111111111000000000 01111111100000111111100000000001111111111111111111000000000 00011111100000111111100000000011111110000000111111000000000 00011111100000111111100000000111111100000000000000000000000 00011111111111111111000000000111111100000000000000000000000 00011111111111111110000000000111111100000000000000000000000 00011111111111111111000000000111111100000000000000000000000 00011111100000111111100000000111111100000000000000000000000 00011111100000111111100000000111111100000000000000000000000 00011111100000111111100000000011111110000000111111000000000 01111111100000111111100000000001111111111111111111000000000 01111111100000111111101111110000111111111111111111011111100 01111111100000111111101111110000001111111111111111011111100 01111111100000111111101111110000000001111111111111011111100 00000000000000000000000000000000000000000000000000000000000’ F intarray(binstring) Line 171 ⟶ 170: R intmatrix.map(row -> row.map(p -> (I p {‘#’} E ‘.’)).join(‘’)).join("\n") F ~~neighbours_arr~~neighbours_array(x, y, image) ‘Return 8-neighbours of point p1 of picture, in order’ V i = image Line 196 ⟶ 195: L(y) 1 .< image.len - 1 L(x) 1 .< image[0].len - 1 V n = ~~neighbours_arr~~neighbours_array(x, y, image) V (P2, P3, P4, P5, P6, P7, P8, P9) = neighbours_tuple(x, y, image) I (image[y][x] == 1 & P4 * P6 * P8 == 0 & P2 * P4 * P6 == 0 & transitions(n) == 1 & sum(n) C 2..6) Line 205 ⟶ 204: L(y) 1 .< image.len - 1 L(x) 1 .< image[0].len - 1 V n = ~~neighbours_arr~~neighbours_array(x, y, image) V (P2, P3, P4, P5, P6, P7, P8, P9) = neighbours_tuple(x, y, image) I (image[y][x] == 1 & P2 * P6 * P8 == 0 & P2 * P4 * P8 == 0 & transitions(n) == 1 & sum(n) C 2..6) Line 217 ⟶ 216: print("\nFrom:\n#.".format(toTxt(image))) V after = zhangSuen(&image) print("\nTo thinned:\n#.".format(toTxt(after)))</~~lang~~syntaxhighlight> {{out}} Line 261 ⟶ 260: ........................................................... ........................................................... </pre> =={{header\|Action!}}== <syntaxhighlight lang="action!">PROC DrawImage(BYTE ARRAY image BYTE x,y,width,height) BYTE i,j BYTE POINTER ptr Color=2 FOR j=0 TO height-1 DO Plot(x,j+y) DrawTo(x+width-1,j+y) OD Color=1 ptr=image FOR j=0 TO height-1 DO FOR i=0 TO width-1 DO IF ptr^ THEN Plot(i+x,j+y) FI ptr==+1 OD OD RETURN PROC Thinning(BYTE ARRAY image BYTE width,height) DEFINE PTR="CARD" DEFINE MAX="200" PTR ARRAY change(MAX) BYTE POINTER p1,p2,p3,p4,p5,p6,p7,p8,p9,p68,p24 INT count,i BYTE x,y,sum,step1 step1=1 DO count=0 p1=image p8=p1-1 p4=p1+1 p2=p1-width p6=p1+width p9=p2-1 p3=p2+1 p7=p6-1 p5=p6+1 FOR y=0 TO height-1 DO FOR x=0 TO width-1 DO IF p1^=1 AND x>0 AND y>0 AND x<width-1 AND y<height-1 THEN sum=p2^+p3^+p4^+p5^+p6^+p7^+p8^+p9^ IF sum>=2 AND sum<=6 THEN sum=0 IF p3^>p2^ THEN sum==+1 FI IF p4^>p3^ THEN sum==+1 FI IF p5^>p4^ THEN sum==+1 FI IF p6^>p5^ THEN sum==+1 FI IF p7^>p6^ THEN sum==+1 FI IF p8^>p7^ THEN sum==+1 FI IF p9^>p8^ THEN sum==+1 FI IF p2^>p9^ THEN sum==+1 FI IF sum=1 THEN IF step1 THEN p24=p4 p68=p6 ELSE p24=p2 p68=p8 FI IF p2^+p4^+p68^<3 AND p24^+p6^+p8^<3 THEN change(count)=p1 count==+1 FI FI FI FI p1==+1 p2==+1 p3==+1 p4==+1 p5==+1 p6==+1 p7==+1 p8==+1 p9==+1 OD OD step1=1-step1 FOR i=0 TO count-1 DO p1=change(i) p1^=0 OD UNTIL count=0 OD RETURN PROC Main() BYTE ARRAY image1=[ 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] BYTE ARRAY image2=[ 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 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 1 1 1 1 1 1 1 1 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 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 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 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 1 1 1 1 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 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 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 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 1 1 1 1 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 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 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 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 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 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 0 1 1 1 1 1 1 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 0 1 1 1 1 1 1 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 0 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 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 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] BYTE width1=[32],height1=[10],width2=[59],height2=[18] BYTE CH=$02FC Graphics(7+16) Color=1 SetColor(0,0,$00) SetColor(4,0,$04) SetColor(1,0,$0C) DrawImage(image1,0,0,width1,height1) Thinning(image1,width1,height1) DrawImage(image1,width1+10,0,width1,height1) DrawImage(image2,0,height1+10,width2,height2) Thinning(image2,width2,height2) DrawImage(image2,width2+10,height1+10,width2,height2) DO UNTIL CH#$FF OD CH=$FF RETURN</syntaxhighlight> {{out}} [https://gitlab.com/amarok8bit/action-rosetta-code/-/raw/master/images/Zhang-Suen_thinning_algorithm.png Screenshot from Atari 8-bit computer] =={{header\|AppleScript}}== <syntaxhighlight lang="applescript">-- Params: -- List of lists (rows) of "pixel" values. -- Record indicating the values representing black and white. on ZhangSuen(matrix, {black:black, white:white}) script o property matrix : missing value property changePixels : missing value on A(neighbours) -- Count transitions from white to black. set sum to 0 repeat with i from 1 to 8 if ((neighbours's item i is white) and (neighbours's item (i mod 8 + 1) is black)) then set sum to sum + 1 end repeat return sum end A on B(neighbours) -- Count neighbouring black pixels. set sum to 0 repeat with p in neighbours if (p's contents is black) then set sum to sum + 1 end repeat return sum end B end script set o's matrix to matrix set rowCount to (count o's matrix) set columnCount to (count o's matrix's beginning) -- Assumed to be the same for every row. repeat until (o's changePixels is {}) repeat with step from 1 to 2 set o's changePixels to {} repeat with r from 2 to (rowCount - 1) repeat with c from 2 to (columnCount - 1) if (o's matrix's item r's item c is black) then tell (a reference to o's matrix) to ¬ set neighbours to {item (r - 1)'s item c, item (r - 1)'s item (c + 1), ¬ item r's item (c + 1), item (r + 1)'s item (c + 1), item (r + 1)'s item c, ¬ item (r + 1)'s item (c - 1), item r's item (c - 1), item (r - 1)'s item (c - 1)} set blackCount to o's B(neighbours) if ((blackCount > 1) and (blackCount < 7) and (o's A(neighbours) is 1)) then set {P2, x, P4, x, P6, x, P8} to neighbours if (step is 1) then set toChange to ((P4 is white) or (P6 is white) or ((P2 is white) and (P8 is white))) else set toChange to ((P2 is white) or (P8 is white) or ((P4 is white) and (P6 is white))) end if if (toChange) then set end of o's changePixels to {r, c} end if end if end repeat end repeat if (o's changePixels is {}) then exit repeat repeat with pixel in o's changePixels set {r, c} to pixel set o's matrix's item r's item c to white end repeat end repeat end repeat return o's matrix -- or: return matrix -- The input has been edited in place. end ZhangSuen on join(lst, delim) set astid to AppleScript's text item delimiters set AppleScript's text item delimiters to delim set txt to lst as text set AppleScript's text item delimiters to astid return txt end join on demo() set pattern to "00000000000000000000000000000000 01111111110000000111111110000000 01110001111000001111001111000000 01110000111000001110000111000000 01110001111000001110000000000000 01111111110000001110000000000000 01110111100000001110000111000000 01110011110011101111001111011100 01110001111011100111111110011100 00000000000000000000000000000000" set matrix to pattern's paragraphs repeat with thisRow in matrix set thisRow's contents to thisRow's characters end repeat ZhangSuen(matrix, {black:"1", white:"0"}) repeat with thisRow in matrix set thisRow's contents to join(thisRow, "") end repeat return join(matrix, linefeed) end demo return demo()</syntaxhighlight> {{output}} <pre>"00000000000000000000000000000000 00111111100000000011111100000000 00100000100000000110000000000000 00100000010000000100000000000000 00100000100000000100000000000000 00111110100000000100000000000000 00000001100000000100000000000000 00000000100001000110000110001000 00000000010000000001111000000000 00000000000000000000000000000000"</pre> Alternative demo: <syntaxhighlight lang="applescript">on demo() set pattern to " ################# ############# ################## ################ ################### ################## ######## ####### ################### ###### ####### ####### ###### ###### ####### ####### ################# ####### ################ ####### ################# ####### ###### ####### ####### ###### ####### ####### ###### ####### ####### ###### ######## ####### ################### ######## ####### ###### ################## ###### ######## ####### ###### ################ ###### ######## ####### ###### ############# ###### " set matrix to pattern's paragraphs repeat with thisRow in matrix set thisRow's contents to thisRow's characters end repeat ZhangSuen(matrix, {black:"#", white:space}) repeat with thisRow in matrix set thisRow's contents to join(thisRow, "") end repeat return join(matrix, linefeed) end demo return demo()</syntaxhighlight> {{output}} <pre> # ########## ####### ## # #### # # # ## # # # # # # # # # ############ # # # # # # # # # # # # # # ## # ############ ### ### </pre> Line 266 ⟶ 556: {{works with\|AutoHotkey_L}} Reads input from a text file and writes output to a different text file (first creating the file, if necessary). <~~lang~~syntaxhighlight ~~AutoHotkey~~lang="autohotkey">FileIn := A_ScriptDir "\Zhang-Suen.txt" FileOut := A_ScriptDir "\NewFile.txt" Line 344 ⟶ 634: return 1 return Neighbors }</~~lang~~syntaxhighlight> '''Output:''' <pre> Line 356 ⟶ 646: # #### </pre> =={{header\|BASIC}}== ==={{header\|FreeBASIC}}=== <syntaxhighlight lang="freebasic">' version 08-10-2016 ' compile with: fbc -s console Data "00000000000000000000000000000000" Data "01111111110000000111111110000000" Data "01110001111000001111001111000000" Data "01110000111000001110000111000000" Data "01110001111000001110000000000000" Data "01111111110000001110000000000000" Data "01110111100000001110000111000000" Data "01110011110011101111001111011100" Data "01110001111011100111111110011100" Data "00000000000000000000000000000000" Data "END" ' ------=< MAIN >=------ Dim As UInteger x, y, m, n Dim As String input_str Do ' find out how big it is Read input_str If input_str = "END" Then Exit Do If x < Len(input_str) Then x = Len(input_str) y = y + 1 Loop m = x -1 : n = y -1 ReDim As UByte old(m, n), new_(m, n) y = 0 Restore ' restore data pointer Do ' put data in array Read input_str If input_str="END" Then Exit Do For x = 0 To Len(input_str) -1 old(x,y) = input_str[x] - Asc("0") ' print image If old(x, y) = 0 Then Print "."; Else Print "#"; Next Print y = y + 1 Loop 'corners and sides do not change For x = 0 To m new_(x, 0) = old(x, 0) new_(x, n) = old(x, n) Next For y = 0 To n new_(0, y) = old(0, y) new_(m, y) = old(m, y) Next Dim As UInteger tmp, change, stage = 1 Do change = 0 For y = 1 To n -1 For x = 1 To m -1 ' -1- If old(x,y) = 0 Then ' first condition, p1 must be black new_(x,y) = 0 Continue For End If ' -2- tmp = old(x, y -1) + old(x +1, y -1) tmp = tmp + old(x +1, y) + old(x +1, y +1) + old(x, y +1) tmp = tmp + old(x -1, y +1) + old(x -1, y) + old(x -1, y -1) If tmp < 2 OrElse tmp > 6 Then ' 2 <= B(p1) <= 6 new_(x, y) = 1 Continue For End If ' -3- tmp = 0 If old(x , y ) = 0 And old(x , y -1) = 1 Then tmp += 1 ' p1 > p2 If old(x , y -1) = 0 And old(x +1, y -1) = 1 Then tmp += 1 ' p2 > p3 If old(x +1, y -1) = 0 And old(x +1, y ) = 1 Then tmp += 1 ' p3 > p4 If old(x +1, y ) = 0 And old(x +1, y +1) = 1 Then tmp += 1 ' p4 > p5 If old(x +1, y +1) = 0 And old(x , y +1) = 1 Then tmp += 1 ' p5 > p6 If old(x , y +1) = 0 And old(x -1, y +1) = 1 Then tmp += 1 ' p6 > p7 If old(x -1, y +1) = 0 And old(x -1, y ) = 1 Then tmp += 1 ' p7 > p8 If old(x -1, y ) = 0 And old(x -1, y -1) = 1 Then tmp += 1 ' p8 > p9 If old(x -1, y -1) = 0 And old(x , y -1) = 1 Then tmp += 1 ' p9 > p2 ' tmp = 1 ==> A(P1) = 1 If tmp <> 1 Then new_(x, y) = 1 Continue For End If If (stage And 1) = 1 Then ' step 1 -4- -5- If (old(x, y -1) + old(x +1, y) + old(x, y +1)) = 3 OrElse _ (old(x +1, y) + old(x, y +1) + old(x -1, y)) = 3 Then new_(x, y) = 1 Continue For End If Else ' step 2 -4- -5- If (old(x, y -1) + old(x +1, y) + old(x -1, y)) = 3 OrElse _ (old(x, y -1) + old(x, y +1) + old(x -1, y)) = 3 Then new_(x, y) = 1 Continue For End If End If ' all condition are met, make p1 white (0) new_(x, y) = 0 change = 1 ' flag change Next Next ' copy new_() into old() For y = 0 To n For x = 0 To m old(x, y) = new_(x, y) Next Next stage += 1 Loop Until change = 0 ' stop when there are no changes made Print ' print result Print "End result" For y = 0 To n For x = 0 To m If old(x, y) = 0 Then Print "."; Else Print "#"; Next Print Next ' empty keyboard buffer While Inkey <> "" : Wend Print : Print "hit any key to end program" Sleep End</syntaxhighlight> {{out}} <pre>................................ .#########.......########....... .###...####.....####..####...... .###....###.....###....###...... .###...####.....###............. .#########......###............. .###.####.......###....###...... .###..####..###.####..####.###.. .###...####.###..########..###.. ................................ End result ................................ ..#######.........######........ ..#.....#........##............. ..#......#.......#.............. ..#.....#........#.............. ..#####.#........#.............. .......##........#.............. ........#....#...##....##...#... .........#.........####......... ................................</pre> ==={{header\|VBA}}=== {{trans\|Phix}} <syntaxhighlight lang="vb">Public n As Variant Private Sub init() n = [{-1,0;-1,1;0,1;1,1;1,0;1,-1;0,-1;-1,-1;-1,0}] End Sub Private Function AB(text As Variant, y As Integer, x As Integer, step As Integer) As Variant Dim wtb As Integer Dim bn As Integer Dim prev As String: prev = "#" Dim next_ As String Dim p2468 As String For i = 1 To UBound(n) next_ = Mid(text(y + n(i, 1)), x + n(i, 2), 1) wtb = wtb - (prev = "." And next_ <= "#") bn = bn - (i > 1 And next_ <= "#") If (i And 1) = 0 Then p2468 = p2468 & prev prev = next_ Next i If step = 2 Then '-- make it p6842 p2468 = Mid(p2468, 3, 2) & Mid(p2468, 1, 2) 'p2468 = p2468(3..4)&p2468(1..2) End If Dim ret(2) As Variant ret(0) = wtb ret(1) = bn ret(2) = p2468 AB = ret End Function Private Sub Zhang_Suen(text As Variant) Dim wtb As Integer Dim bn As Integer Dim changed As Boolean, changes As Boolean Dim p2468 As String '-- (p6842 for step 2) Dim x As Integer, y As Integer, step As Integer Do While True changed = False For step = 1 To 2 changes = False For y = 1 To UBound(text) - 1 For x = 2 To Len(text(y)) - 1 If Mid(text(y), x, 1) = "#" Then ret = AB(text, y, x, step) wtb = ret(0) bn = ret(1) p2468 = ret(2) If wtb = 1 _ And bn >= 2 And bn <= 6 _ And InStr(1, Mid(p2468, 1, 3), ".") _ And InStr(1, Mid(p2468, 2, 3), ".") Then changes = True text(y) = Left(text(y), x - 1) & "!" & Right(text(y), Len(text(y)) - x) End If End If Next x Next y If changes Then For y = 1 To UBound(text) - 1 text(y) = Replace(text(y), "!", ".") Next y changed = True End If Next step If Not changed Then Exit Do Loop Debug.Print Join(text, vbCrLf) End Sub Public Sub main() init Dim Small_rc(9) As String Small_rc(0) = "................................" Small_rc(1) = ".#########.......########......." Small_rc(2) = ".###...####.....####..####......" Small_rc(3) = ".###....###.....###....###......" Small_rc(4) = ".###...####.....###............." Small_rc(5) = ".#########......###............." Small_rc(6) = ".###.####.......###....###......" Small_rc(7) = ".###..####..###.####..####.###.." Small_rc(8) = ".###...####.###..########..###.." Small_rc(9) = "................................" Zhang_Suen (Small_rc) End Sub</syntaxhighlight>{{out}} <pre>................................ ...######.........######........ ...#....#.........#....##....... ...#....#.........#......#...... ...#....#.........#............. ...####.#.........#............. .......##.........#............. ........#....#....#....##...#... .........#....#....####......#.. ................................</pre> =={{header\|C}}== Line 365 ⟶ 912: </pre> The images before and after thinning are also printed on the console. <syntaxhighlight lang="c"> ~~<lang C>~~ #include<stdlib.h> #include<stdio.h> Line 526 ⟶ 1,073: return 0; } </syntaxhighlight> ~~</lang>~~ Contents of input file : zhImage.txt Line 596 ⟶ 1,143: =={{header\|C++}}== Compiled with --std=c++14 <~~lang~~syntaxhighlight ~~CPP~~lang="cpp">#include <iostream> #include <string> #include <sstream> Line 837 ⟶ 1,384: return 0; } </syntaxhighlight> ~~</lang>~~ Output: Line 911 ⟶ 1,458: =={{header\|D}}== This uses the module from the Bitmap Task. And it performs no heap allocations. <~~lang~~syntaxhighlight lang="d">import std.stdio, std.algorithm, std.string, std.functional, std.typecons, std.typetuple, bitmap; Line 1,038 ⟶ 1,585: writeln; } }</~~lang~~syntaxhighlight> {{out}} <pre>From: Line 1,137 ⟶ 1,684: =={{header\|Elena}}== ELENA 56.0x : {{trans\|Java}} <~~lang~~syntaxhighlight lang="elena">import system'collections; import system'routines; import extensions; Line 1,164 ⟶ 1,711: " "}; static int[][] nbrs = new int[][] { new int[]{0, -1}, new int[]{1, -1}, new int[]{1, 0}, new int[]{1, 1}, new int[]{0, 1}, Line 1,170 ⟶ 1,717: }; static int[][][] nbrGroups = new int[][][] { new int[][]{new int[]{0, 2, 4}, new int[]{2, 4, 6}}, Line 1,203 ⟶ 1,750: int count := 0; for (int i := 0,; i < nbrs.Length, - 1; i += 1) { if (self[r + nbrs[i][1]][c + nbrs[i + 1][0]] == $35) { count += 1 } }; Line 1,216 ⟶ 1,763: int count := 0; for (int i := 0,; i < nbrs.Length, - 1; i += 1) { if (self[r + nbrs[i][1]][c + nbrs[i][0]] == $32) Line 1,234 ⟶ 1,781: int count := 0; var group := nbrGroups[step]; for(int i := 0,; i < 3,2; i += 1) { for(int j := 0,; j < group[i].Length,; j += 1) { var nbr := nbrs[group[i][j]]; if (self[r + nbr[1]][c + nbr[0]] == $32) { count := count + 1; ~~^ true~~$break; }; ~~^ false~~ } }; Line 1,261 ⟶ 1,806: firstStep := firstStep.Inverted; for(int r := 1,; r < self.Rows, - 1; r += 1) { for(int c := 1,; c < self.Columns, - 1; c += 1) { if(self.proceed(r,c,toWhite,firstStep)) Line 1,270 ⟶ 1,815: }; toWhite.forEach::(p){ self[p.y][p.x] := $32 }; toWhite.clear() } Line 1,279 ⟶ 1,824: var it := self.enumerator(); it.forEach::(ch){ console.print(ch," ") }; while (it.next()) { console.writeLine(); it.forEach::(ch){ console.print(ch," ") } } } Line 1,306 ⟶ 1,851: console.readChar() }</~~lang~~syntaxhighlight> {{out}} <pre> # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # ~~# # #~~ # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # Line 1,330 ⟶ 1,875: =={{header\|Elixir}}== {{trans\|Ruby}} <~~lang~~syntaxhighlight lang="elixir">defmodule ZhangSuen do @neighbours [{-1,0},{-1,1},{0,1},{1,1},{1,0},{1,-1},{0,-1},{-1,-1}] # 8 neighbours Line 1,419 ⟶ 1,964: 00000000000000000000000000000000 """ ZhangSuen.thinning(str, ?1)</~~lang~~syntaxhighlight> {{out}} Line 1,482 ⟶ 2,027: =={{header\|Fortran}}== With F90 came standardisation of a variety of array manipulation facilities. Since the image array is to be inspected as a whole then adjusted rather than adjusted step-by-step as it is inspected, the first thought was to employ the special facility of the FOR ALL statement, which is that in an expression such as <~~lang~~syntaxhighlight ~~Fortarn~~lang="fortarn">FOR ALL (i = 2:n - 1) A(i) = (A(i - 1) + A(i) + A(i + 1))/3</~~lang~~syntaxhighlight> all right-hand-side expressions will be evaluated with the original values of the array, while in the less special array assignment <~~lang~~syntaxhighlight ~~Fortran~~lang="fortran">A(2:N - 1) = (A(1:N - 2) + A(2:N - 1) + A(3:N))/3</~~lang~~syntaxhighlight> as in the case of the equivalent DO-loop, the processing will be with a mixture of old and new values as the loop proceeds. So, that suggests something like <~~lang~~syntaxhighlight ~~Fortran~~lang="fortran"> FOR ALL (I = 2:N - 1, J = 2:M - 1) WHERE(DOT(I,J) .NE. 0) DOT(I,J) = ADJUST(DOT,I,J)</~~lang~~syntaxhighlight> This requires function ADJUST to be a "pure" function, and they are not supposed to perpetrate side effects, such as one reporting that any adjustment was made. Nor is it clear that array DOT must be presented as a parameter either as the entire array or as element DOT(i,j), or if not, that it can be global to function ADJUST - which would also be an impurity - and for that matter, variables I and J could be global also... Instead, thought turned to more closely following the task specification, which involves producing a list of elements to be adjusted after an inspection pass. Given that array DOT is two-dimensional, it would be nice if an element could be indexed via an expression such as <code>DOT(INDEX)</code> where INDEX was an array of two elements with INDEX(1) = i, and INDEX(2) = j, so as to access DOT(i,j) If this were possible, then obviously one could hope that array INDEX could be extended so as to store the multiple elements of a list of such locations to access, with a view to <code>DOT(INDEX(1:n)) = 0</code> adjusting the image. Alas, such a syntax form is not accommodated. However, F90 also introduced the ability to define and use compound data types, such as the type PLACE as used below. It is not possible to define a type of a special, recognised form, such as say "SUBSCRIPT LIST" that can be used as dreamt of above, so the components are just ordinary variables. Two ordinary arrays could be used, one for each of the two subscripts, or a compound type could be devised in a hint towards self-documentation. Thus, <~~lang~~syntaxhighlight ~~Fortran~~lang="fortran"> DOT(WHACK(1:WHACKCOUNT).I,WHACK(1:WHACKCOUNT).J) = 0</~~lang~~syntaxhighlight> But it doesn't work... After a fair amount of head scratching, not at all assisted by the woolly generalities and inane examples of the compiler's "help" collection, it became apparent that the expression did not work through a list of indices as anticipated, but instead, for ''each'' value of the first index, ''all'' the values of the second index were selected. Thus, instead of the first change being DOT(WHACK('''1''').I,WHACK('''1''').J) only, it was DOT(WHACK('''1''').I,WHACK('''1:WHACKCOUNT''').J) that were being cleared. Accordingly, the fancy syntax has to be abandoned in favour of a specific DO-loop. <~~lang~~syntaxhighlight ~~Fortran~~lang="fortran"> MODULE ZhangSuenThinning !Image manipulation. CONTAINS SUBROUTINE ZST(DOT) !Attempts to thin out thick lines. Line 1,599 ⟶ 2,144: CALL SHOW(IMAGE) END PROGRAM POKE </~~lang~~syntaxhighlight> Output: Line 1,627 ⟶ 2,172: ................................ </pre> ~~=={{header\|FreeBASIC}}==~~ ~~<lang freebasic>' version 08-10-2016~~ ~~' compile with: fbc -s console~~ ~~Data "00000000000000000000000000000000"~~ ~~Data "01111111110000000111111110000000"~~ ~~Data "01110001111000001111001111000000"~~ ~~Data "01110000111000001110000111000000"~~ ~~Data "01110001111000001110000000000000"~~ ~~Data "01111111110000001110000000000000"~~ ~~Data "01110111100000001110000111000000"~~ ~~Data "01110011110011101111001111011100"~~ ~~Data "01110001111011100111111110011100"~~ ~~Data "00000000000000000000000000000000"~~ ~~Data "END"~~ ~~' ------=< MAIN >=------~~ ~~Dim As UInteger x, y, m, n~~ ~~Dim As String input_str~~ ~~Do ' find out how big it is~~ ~~Read input_str~~ ~~If input_str = "END" Then Exit Do~~ ~~If x < Len(input_str) Then x = Len(input_str)~~ ~~y = y + 1~~ ~~Loop~~ ~~m = x -1 : n = y -1~~ ~~ReDim As UByte old(m, n), new_(m, n)~~ ~~y = 0~~ ~~Restore ' restore data pointer~~ ~~Do ' put data in array~~ ~~Read input_str~~ ~~If input_str="END" Then Exit Do~~ ~~For x = 0 To Len(input_str) -1~~ ~~old(x,y) = input_str[x] - Asc("0")~~ ~~' print image~~ ~~If old(x, y) = 0 Then Print "."; Else Print "#";~~ ~~Next~~ ~~Print~~ ~~y = y + 1~~ ~~Loop~~ ~~'corners and sides do not change~~ ~~For x = 0 To m~~ ~~new_(x, 0) = old(x, 0)~~ ~~new_(x, n) = old(x, n)~~ ~~Next~~ ~~For y = 0 To n~~ ~~new_(0, y) = old(0, y)~~ ~~new_(m, y) = old(m, y)~~ ~~Next~~ ~~Dim As UInteger tmp, change, stage = 1~~ Do ~~change = 0~~ ~~For y = 1 To n -1~~ ~~For x = 1 To m -1~~ ~~' -1-~~ ~~If old(x,y) = 0 Then ' first condition, p1 must be black~~ ~~new_(x,y) = 0~~ ~~Continue For~~ ~~End If~~ ~~' -2-~~ ~~tmp = old(x, y -1) + old(x +1, y -1)~~ ~~tmp = tmp + old(x +1, y) + old(x +1, y +1) + old(x, y +1)~~ ~~tmp = tmp + old(x -1, y +1) + old(x -1, y) + old(x -1, y -1)~~ ~~If tmp < 2 OrElse tmp > 6 Then ' 2 <= B(p1) <= 6~~ ~~new_(x, y) = 1~~ ~~Continue For~~ ~~End If~~ ~~' -3-~~ ~~tmp = 0~~ ~~If old(x , y ) = 0 And old(x , y -1) = 1 Then tmp += 1 ' p1 > p2~~ ~~If old(x , y -1) = 0 And old(x +1, y -1) = 1 Then tmp += 1 ' p2 > p3~~ ~~If old(x +1, y -1) = 0 And old(x +1, y ) = 1 Then tmp += 1 ' p3 > p4~~ ~~If old(x +1, y ) = 0 And old(x +1, y +1) = 1 Then tmp += 1 ' p4 > p5~~ ~~If old(x +1, y +1) = 0 And old(x , y +1) = 1 Then tmp += 1 ' p5 > p6~~ ~~If old(x , y +1) = 0 And old(x -1, y +1) = 1 Then tmp += 1 ' p6 > p7~~ ~~If old(x -1, y +1) = 0 And old(x -1, y ) = 1 Then tmp += 1 ' p7 > p8~~ ~~If old(x -1, y ) = 0 And old(x -1, y -1) = 1 Then tmp += 1 ' p8 > p9~~ ~~If old(x -1, y -1) = 0 And old(x , y -1) = 1 Then tmp += 1 ' p9 > p2~~ ~~' tmp = 1 ==> A(P1) = 1~~ ~~If tmp <> 1 Then~~ ~~new_(x, y) = 1~~ ~~Continue For~~ ~~End If~~ ~~If (stage And 1) = 1 Then~~ ~~' step 1 -4- -5-~~ ~~If (old(x, y -1) + old(x +1, y) + old(x, y +1)) = 3 OrElse _~~ ~~(old(x +1, y) + old(x, y +1) + old(x -1, y)) = 3 Then~~ ~~new_(x, y) = 1~~ ~~Continue For~~ ~~End If~~ ~~Else~~ ~~' step 2 -4- -5-~~ ~~If (old(x, y -1) + old(x +1, y) + old(x -1, y)) = 3 OrElse _~~ ~~(old(x, y -1) + old(x, y +1) + old(x -1, y)) = 3 Then~~ ~~new_(x, y) = 1~~ ~~Continue For~~ ~~End If~~ ~~End If~~ ~~' all condition are met, make p1 white (0)~~ ~~new_(x, y) = 0~~ ~~change = 1 ' flag change~~ ~~Next~~ ~~Next~~ ~~' copy new_() into old()~~ ~~For y = 0 To n~~ ~~For x = 0 To m~~ ~~old(x, y) = new_(x, y)~~ ~~Next~~ ~~Next~~ ~~stage += 1~~ ~~Loop Until change = 0 ' stop when there are no changes made~~ ~~Print ' print result~~ ~~Print "End result"~~ ~~For y = 0 To n~~ ~~For x = 0 To m~~ ~~If old(x, y) = 0 Then Print "."; Else Print "#";~~ ~~Next~~ ~~Print~~ ~~Next~~ ~~' empty keyboard buffer~~ ~~While Inkey <> "" : Wend~~ ~~Print : Print "hit any key to end program"~~ ~~Sleep~~ ~~End</lang>~~ ~~{{out}}~~ ~~<pre>................................~~ ~~.#########.......########.......~~ ~~.###...####.....####..####......~~ ~~.###....###.....###....###......~~ ~~.###...####.....###.............~~ ~~.#########......###.............~~ ~~.###.####.......###....###......~~ ~~.###..####..###.####..####.###..~~ ~~.###...####.###..########..###..~~ ~~................................~~ ~~End result~~ ~~................................~~ ~~..#######.........######........~~ ~~..#.....#........##.............~~ ~~..#......#.......#..............~~ ~~..#.....#........#..............~~ ~~..#####.#........#..............~~ ~~.......##........#..............~~ ~~........#....#...##....##...#...~~ ~~.........#.........####.........~~ ~~................................</pre>~~ =={{header\|Go}}== <~~lang~~syntaxhighlight lang="go">package main import ( Line 1,977 ⟶ 2,362: } } }</~~lang~~syntaxhighlight> {{out}} <pre> Line 1,993 ⟶ 2,378: =={{header\|Groovy}}== <~~lang~~syntaxhighlight lang="groovy">def zhangSuen(text) { def image = text.split('\n').collect { line -> line.collect { it == '#' ? 1 : 0} } def p2, p3, p4, p5, p6, p7, p8, p9 Line 2,017 ⟶ 2,402: while (reduce(step1) \| reduce(step2)); image.collect { line -> line.collect { it ? '#' : '.' }.join('') }.join('\n') }</~~lang~~syntaxhighlight> Testing: <~~lang~~syntaxhighlight lang="groovy">def small = """\ ................................ .#########.......########....... Line 2,057 ⟶ 2,442: println zhangSuen(it) println() }</~~lang~~syntaxhighlight> Output: <pre>From: Line 2,122 ⟶ 2,507: =={{header\|Haskell}}== <~~lang~~syntaxhighlight ~~Haskell~~lang="haskell">import Data.Array import qualified Data.List as List Line 2,243 ⟶ 2,628: main :: IO () main = mapM_ (putStrLn . showBWArray . thin . toBWArray) [sampleExA, sampleExB]</~~lang~~syntaxhighlight> {{out}} <pre> ####### ###### Line 2,274 ⟶ 2,659: =={{header\|J}}== '''Solution:''' <~~lang~~syntaxhighlight lang="j">isBlackPx=: '1'&=;._2 NB. boolean array of black pixels toImage=: [: , LF ,.~ '01' {~ ] NB. convert to original representation frameImg=: 0 ,. 0 , >:@$ {. ] NB. adds border of 0's to image Line 2,298 ⟶ 2,683: step2=: whiten frameImg@(cond2 neighbrs) zhangSuen=: [: toImage [: step2@step1^:_ isBlackPx</~~lang~~syntaxhighlight> '''Alternative, explicit representation of last verb above''' <~~lang~~syntaxhighlight lang="j">zhangSuenX=: verb define img=. isBlackPx y whilst. 0 < +/ , msk1 +.&-. msk2 do. Line 2,309 ⟶ 2,694: end. toImage img )</~~lang~~syntaxhighlight> '''Example Use:''' <~~lang~~syntaxhighlight lang="j">toASCII=: ' #' {~ '1'&=;._2 NB. convert to ASCII representation ExampleImg=: noun define Line 2,336 ⟶ 2,721: # # ## ## # # #### </~~lang~~syntaxhighlight> =={{header\|Java}}== {{works with\|Java\|7}} <~~lang~~syntaxhighlight lang="java">import java.awt.Point; import java.util.; Line 2,456 ⟶ 2,841: System.out.println(row); } }</~~lang~~syntaxhighlight> Output: Line 2,478 ⟶ 2,863: =={{header\|JavaScript}}== {{trans\|Java}} <~~lang~~syntaxhighlight lang="javascript">function Point(x, y) { this.x = x; this.y = y; Line 2,583 ⟶ 2,968: return ZhangSuen; }()); ZhangSuen.main(null);</~~lang~~syntaxhighlight> Output: Line 2,604 ⟶ 2,989: =={{header\|Julia}}== <~~lang~~syntaxhighlight lang="julia"> const pixelstring = "00000000000000000000000000000000" Line 2,681 ⟶ 3,066: asciiprint(zsthinning(pixels))</~~lang~~syntaxhighlight> {{output}}<pre> loop number 1 Line 2,699 ⟶ 3,084: =={{header\|Kotlin}}== {{trans\|Java}} <~~lang~~syntaxhighlight lang="scala">// version 1.1.2 class Point(val x: Int, val y: Int) Line 2,798 ⟶ 3,183: fun main(args: Array<String>) { thinImage() }</~~lang~~syntaxhighlight> {{out}} Line 2,821 ⟶ 3,206: =={{header\|Lua}}== <~~lang~~syntaxhighlight lang="lua">function zhangSuenThin(img) local dirs={ { 0,-1}, Line 2,961 ⟶ 3,346: zhangSuenThin(image) </syntaxhighlight> ~~</lang>~~ Output: Line 2,977 ⟶ 3,362: </pre> =={{header\|Mathematica}}/{{header\|Wolfram Language}}== Mathematica supports directly the Thinning methods "Morphological" and "MedialAxis". The Zhang-Suen algorithm implementation could be done with: <~~lang~~syntaxhighlight ~~Mathematica~~lang="mathematica">nB[mat_] := Delete[mat // Flatten, 5] // Total; nA[mat_] := Module[{l}, Line 3,018 ⟶ 3,402: FixedPoint[iter, dat]</~~lang~~syntaxhighlight> Which results in: Line 3,162 ⟶ 3,546: =={{header\|Nim}}== <~~lang~~syntaxhighlight ~~Nim~~lang="nim">import math, sequtils, strutils type Line 3,255 ⟶ 3,639: echo() echo "Output image:" echo output</~~lang~~syntaxhighlight> {{out}} Line 3,285 ⟶ 3,669: =={{header\|Perl}}== {{trans\|Raku}} <syntaxhighlight lang ="perl">use ~~List::Util qw(sum min)~~v5.36.0; no warnings 'uninitialized'; use List::Util qw(sum min); $source = <<'END'; Line 3,323 ⟶ 3,709: do { sub seewhite ($w1,$w2) { my~~($w1,$w2) =~~ @_results; sub cycles (@neighbors) { my $c; $c += $neighbors[$_] < $neighbors[($_+1)%8] for 0..$#neighbors; $c } ~~my(@results);~~ sub ~~cycles~~blacks ~~{ my~~(@neighbors)~~=@_;~~ my{ ~~$c;~~sum ~~$c += $~~@neighbors~~[$_] < $neighbors[($_+1)%8] for 0..$#neighbors; return $c~~ } ~~sub blacks { my(@neighbors)=@_; sum @neighbors }~~ @prior = @cand; @cand = (); for $p (@prior) { Line 3,338 ⟶ 3,722: } } ~~return~~ @results; } @goners1 = seewhite [0,2,4], [2,4,6]; @black[@goners1] = 0 x @goners1; @goners2 = seewhite [0,2,6], [0,4,6]; @black[@goners2] = 0 x @goners2; } ~~until~~while @goners1 ~~== 0 and~~or @goners2 ~~== 0~~; while (@black) { push @thinned, join '', qw<. #>[splice(@black,0,$h)] } ~~print~~say join "\n", @thinned;</~~lang~~syntaxhighlight> {{out}} <pre>............................................................ Line 3,369 ⟶ 3,753: =={{header\|Phix}}== <!--<syntaxhighlight lang="phix">(phixonline)--> ~~<lang Phix>constant n = {{-1,0},{-1,1},{0,1},{1,1},{1,0},{1,-1},{0,-1},{-1,-1},{-1,0}};~~ <span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span> <span style="color: #008080;">constant</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">}};</span> ~~function AB(sequence text, integer y, x, step)~~ ~~integer wtb = 0, bn = 0~~ <span style="color: #008080;">function</span> <span style="color: #000000;">AB</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">text</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">step</span><span style="color: #0000FF;">)</span> ~~integer prev = '#', next~~ <span style="color: #004080;">integer</span> <span style="color: #000000;">wtb</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">bn</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span> ~~string p2468 = ""~~ <span style="color: #004080;">integer</span> <span style="color: #000000;">prev</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">'#'</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">next</span> ~~for i=1 to length(n) do~~ <span style="color: #004080;">string</span> <span style="color: #000000;">p2468</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""</span> ~~next = text[y+n[i][1]][x+n[i][2]]~~ <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span> ~~wtb += (prev='.' and next<='#')~~ <span style="color: #000000;">next</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">text</span><span style="color: #0000FF;">[</span><span style="color: #000000;">y</span><span style="color: #0000FF;">+</span><span style="color: #000000;">n</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]][</span><span style="color: #000000;">x</span><span style="color: #0000FF;">+</span><span style="color: #000000;">n</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">]]</span> ~~bn += (i>1 and next<='#')~~ <span style="color: #000000;">wtb</span> <span style="color: #0000FF;">+=</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">prev</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'.'</span> <span style="color: #008080;">and</span> <span style="color: #000000;">next</span><span style="color: #0000FF;"><=</span><span style="color: #008000;">'#'</span><span style="color: #0000FF;">)</span> ~~if and_bits(i,1)=0 then p2468 = append(p2468,prev) end if~~ <span style="color: #000000;">bn</span> <span style="color: #0000FF;">+=</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">i</span><span style="color: #0000FF;">></span><span style="color: #000000;">1</span> <span style="color: #008080;">and</span> <span style="color: #000000;">next</span><span style="color: #0000FF;"><=</span><span style="color: #008000;">'#'</span><span style="color: #0000FF;">)</span> ~~prev = next~~ <span style="color: #008080;">if</span> <span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">i</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span> <span style="color: #000000;">p2468</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">p2468</span><span style="color: #0000FF;">,</span><span style="color: #000000;">prev</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> ~~end for~~ <span style="color: #000000;">prev</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">next</span> ~~if step=2 then -- make it p6842~~ <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> ~~p2468 = p2468[3..4]&p2468[1..2]~~ <span style="color: #008080;">if</span> <span style="color: #000000;">step</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span> <span style="color: #008080;">then</span> <span style="color: #000080;font-style:italic;">-- make it p6842</span> ~~end if~~ <span style="color: #000000;">p2468</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">p2468</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">..</span><span style="color: #000000;">4</span><span style="color: #0000FF;">]&</span><span style="color: #000000;">p2468</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..</span><span style="color: #000000;">2</span><span style="color: #0000FF;">]</span> ~~return {wtb,bn,p2468}~~ <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> ~~end function~~ <span style="color: #008080;">return</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">wtb</span><span style="color: #0000FF;">,</span><span style="color: #000000;">bn</span><span style="color: #0000FF;">,</span><span style="color: #000000;">p2468</span><span style="color: #0000FF;">}</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> ~~procedure Zhang_Suen(sequence text)~~ ~~integer wtb, bn, changed, changes~~ <span style="color: #008080;">procedure</span> <span style="color: #000000;">Zhang_Suen</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">text</span><span style="color: #0000FF;">)</span> ~~string p2468 -- (p6842 for step 2)~~ <span style="color: #004080;">integer</span> <span style="color: #000000;">wtb</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">bn</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">changed</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">changes</span> ~~text = split(text,'\n')~~ <span style="color: #004080;">string</span> <span style="color: #000000;">p2468</span> <span style="color: #000080;font-style:italic;">-- (p6842 for step 2)</span> ~~while 1 do~~ <span style="color: #000000;">text</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">split</span><span style="color: #0000FF;">(</span><span style="color: #000000;">text</span><span style="color: #0000FF;">,</span><span style="color: #008000;">'\n'</span><span style="color: #0000FF;">)</span> ~~changed = 0~~ <span style="color: #008080;">while</span> <span style="color: #000000;">1</span> <span style="color: #008080;">do</span> ~~for step=1 to 2 do~~ <span style="color: #000000;">changed</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span> ~~changes = 0~~ <span style="color: #008080;">for</span> <span style="color: #000000;">step</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">2</span> <span style="color: #008080;">do</span> ~~for y=2 to length(text)-1 do~~ <span style="color: #000000;">changes</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span> ~~for x=2 to length(text[y])-1 do~~ <span style="color: #008080;">for</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">text</span><span style="color: #0000FF;">)-</span><span style="color: #000000;">1</span> <span style="color: #008080;">do</span> ~~if text[y][x]='#' then~~ <span style="color: #008080;">for</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">text</span><span style="color: #0000FF;">[</span><span style="color: #000000;">y</span><span style="color: #0000FF;">])-</span><span style="color: #000000;">1</span> <span style="color: #008080;">do</span> ~~{wtb,bn,p2468} = AB(text,y,x,step)~~ <span style="color: #008080;">if</span> <span style="color: #000000;">text</span><span style="color: #0000FF;">[</span><span style="color: #000000;">y</span><span style="color: #0000FF;">][</span><span style="color: #000000;">x</span><span style="color: #0000FF;">]=</span><span style="color: #008000;">'#'</span> <span style="color: #008080;">then</span> ~~if wtb=1~~ <span style="color: #0000FF;">{</span><span style="color: #000000;">wtb</span><span style="color: #0000FF;">,</span><span style="color: #000000;">bn</span><span style="color: #0000FF;">,</span><span style="color: #000000;">p2468</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">AB</span><span style="color: #0000FF;">(</span><span style="color: #000000;">text</span><span style="color: #0000FF;">,</span><span style="color: #000000;">y</span><span style="color: #0000FF;">,</span><span style="color: #000000;">x</span><span style="color: #0000FF;">,</span><span style="color: #000000;">step</span><span style="color: #0000FF;">)</span> ~~and bn>=2 and bn<=6~~ <span style="color: #008080;">if</span> <span style="color: #000000;">wtb</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> ~~and find('.',p2468[1..3])~~ <span style="color: #008080;">and</span> <span style="color: #000000;">bn</span><span style="color: #0000FF;">>=</span><span style="color: #000000;">2</span> <span style="color: #008080;">and</span> <span style="color: #000000;">bn</span><span style="color: #0000FF;"><=</span><span style="color: #000000;">6</span> ~~and find('.',p2468[2..4])then~~ <span style="color: #008080;">and</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #008000;">'.'</span><span style="color: #0000FF;">,</span><span style="color: #000000;">p2468</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span> ~~changes = 1~~ <span style="color: #008080;">and</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #008000;">'.'</span><span style="color: #0000FF;">,</span><span style="color: #000000;">p2468</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">..</span><span style="color: #000000;">4</span><span style="color: #0000FF;">])</span><span style="color: #008080;">then</span> ~~text[y][x] = '!' -- (logically still black)~~ <span style="color: #000000;">changes</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span> ~~end if~~ <span style="color: #000000;">text</span><span style="color: #0000FF;">[</span><span style="color: #000000;">y</span><span style="color: #0000FF;">][</span><span style="color: #000000;">x</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">'!'</span> <span style="color: #000080;font-style:italic;">-- (logically still black)</span> ~~end if~~ <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> ~~end for~~ <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> ~~end for~~ <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> ~~if changes then~~ <span style="color: #008080;">end</span> ~~for~~<span ystyle=2"color: ~~to length(text)-1 do~~#008080;">for</span> <span style="color: #008080;">if</span> <span style="color: #000000;">changes</span> <span style="color: #008080;">then</span> ~~text[y] = substitute(text[y],"!",".")~~ <span style="color: #008080;">for</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">text</span><span style="color: #0000FF;">)-</span><span style="color: #000000;">1</span> <span style="color: #008080;">do</span> ~~end for~~ <span style="color: #000000;">text</span><span style="color: #0000FF;">[</span><span style="color: #000000;">y</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">substitute</span><span style="color: #0000FF;">(</span><span style="color: #000000;">text</span><span style="color: #0000FF;">[</span><span style="color: #000000;">y</span><span style="color: #0000FF;">],</span><span style="color: #008000;">"!"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"."</span><span style="color: #0000FF;">)</span> ~~changed = 1~~ <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> ~~end if~~ <span style="color: #000000;">changed</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span> ~~end for~~ <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> ~~if not changed then exit end if~~ <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> ~~end while~~ <span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #000000;">changed</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> ~~puts(1,join(text,"\n"))~~ <span style="color: #008080;">end</span> <span style="color: #008080;">while</span> ~~end procedure~~ <span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">text</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n"</span><span style="color: #0000FF;">))</span> <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span> ~~string small_rc = """~~ ~~................................~~ <span style="color: #004080;">string</span> <span style="color: #000000;">small_rc</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""" ~~.#########.......########.......~~ ................~~###~~...~~####~~.....~~####~~..~~####~~...... .###~~....~~######.......###~~....~~#####....... .###...####.....####..~~.....~~####...... .###~~###~~....###......###....~~...~~###...... .###...####.......###....~~###~~......... .###..###~~#..~~###.~~####~~..~~####~~...###............. .###...####.~~###~~..~~#####~~....###....###...... .###..####..###.####..####.###.. ~~................................"""~~ .###...####.###..########..###.. ~~Zhang_Suen(small_rc)</lang>~~ ................................"""</span> <span style="color: #000000;">Zhang_Suen</span><span style="color: #0000FF;">(</span><span style="color: #000000;">small_rc</span><span style="color: #0000FF;">)</span> <!--</syntaxhighlight>--> {{out}} <pre> Line 3,449 ⟶ 3,836: =={{header\|PL/I}}== <syntaxhighlight lang="pl/i">zhang: procedure options (main); /* 8 July 2014 / declare pic(10) bit(32) initial ( Line 3,571 ⟶ 3,958: end B; end zhang;</~~lang~~syntaxhighlight> <pre> [Initial configuration:] Line 3,662 ⟶ 4,049: =={{header\|Python}}== Several input images are converted. <~~lang~~syntaxhighlight lang="python"># -- coding: utf-8 -- # Example from [http://nayefreza.wordpress.com/2013/05/11/zhang-suen-thinning-algorithm-java-implementation/ this blog post]. Line 3,779 ⟶ 4,166: print('\nFrom:\n%s' % toTxt(image)) after = zhangSuen(image) print('\nTo thinned:\n%s' % toTxt(after))</~~lang~~syntaxhighlight> {{out}} Line 3,809 ⟶ 4,196: =={{header\|Racket}}== <~~lang~~syntaxhighlight lang="racket">#lang racket (define (img-01string->vector str) (define lines (regexp-split "\n" str)) Line 3,922 ⟶ 4,309: ; (read-display-thin-display-image e.g.-image/2) ; (newline) (read-display-thin-display-image e.g.-image))</~~lang~~syntaxhighlight> {{out}} Line 3,952 ⟶ 4,339: (formerly Perl 6) Source image may be based on any characters whose low bits are 0 or 1 (which conveniently includes . and #). <syntaxhighlight lang="raku" ~~perl6~~line>my $source = qq:to/EOD/; ................................ .#########.......########....... Line 4,002 ⟶ 4,389: } say @black.splice(0,h).join.trans('01' => '.#') while @black;</~~lang~~syntaxhighlight> {{out}} <pre>Ping: 66 remaining after removing 33 41 49 56 67 71 74 80 83 86 89 99 106 114 119 120 121 131 135 138 146 169 178 195 197 210 215 217 227 230 233 236 238 240 243 246 249 251 253 257 258 259 263 264 266 268 269 270 273 274 279 280 283 284 285 Line 4,022 ⟶ 4,409: =={{header\|REXX}}== <~~lang~~syntaxhighlight lang="rexx">/REXX program thins a NxM character grid using the Zhang-Suen thinning algorithm./ parse arg iFID .; if iFID=='' then iFID='ZHANG_SUEN.DAT' white=' '; @.=white / [↓] read the input character grid. / Line 4,062 ⟶ 4,449: Ps: rm=r-1; rp=r+1; cm=c-1; cp=c+1 /calculate some shortcuts./ p2=@.rm.c\==white; p3=@.rm.cp\==white; p4=@.r.cp\==white; p5=@.rp.cp\==white p6=@.rp.c\==white; p7=@.rp.cm\==white; p8=@.r.cm\==white; p9=@.rm.cm\==white; return</~~lang~~syntaxhighlight> '''output'''   when using the default input: <pre> Line 4,136 ⟶ 4,523: First I define a function zs which given a point and its eight neighbours returns 1 if the point may be culled, 0 otherwise. g indicates if this is step 1 or step 2 in the task description. zs may be changed to remember the step independently if the reader does not wish to explore the algorithm. <~~lang~~syntaxhighlight lang="ruby">class ZhangSuen NEIGHBOUR8 = [[-1,0],[-1,1],[0,1],[1,1],[1,0],[1,-1],[0,-1],[-1,-1]] # 8 neighbors CIRCULARS = NEIGHBOUR8 + [NEIGHBOUR8.first] # P2, ... P9, P2 Line 4,203 ⟶ 4,590: EOS ZhangSuen.new(task_example, "1")</~~lang~~syntaxhighlight> {{out}} Line 4,221 ⟶ 4,608: =={{header\|Sidef}}== {{trans\|Ruby}} <~~lang~~syntaxhighlight lang="ruby">class ZhangSuen(str, black="1") { const NEIGHBOURS = [[-1,0],[-1,1],[0,1],[1,1],[1,0],[1,-1],[0,-1],[-1,-1]] # 8 neighbors const CIRCULARS = (NEIGHBOURS + [NEIGHBOURS.first]) # P2, ... P9, P2 Line 4,277 ⟶ 4,664: EOS ZhangSuen.new(text, black: "1").display</~~lang~~syntaxhighlight> {{out}} <pre> Line 4,291 ⟶ 4,678: </pre> =={{header\|Swift}}== {{trans\|Python}} <syntaxhighlight lang="swift">import UIKit // testing examples let beforeTxt = """ 1100111 1100111 1100111 1100111 1100110 1100110 1100110 1100110 1100110 1100110 1100110 1100110 1111110 0000000 """ let smallrc01 = """ 00000000000000000000000000000000 01111111110000000111111110000000 01110001111000001111001111000000 01110000111000001110000111000000 01110001111000001110000000000000 01111111110000001110000000000000 01110111100000001110000111000000 01110011110011101111001111011100 01110001111011100111111110011100 00000000000000000000000000000000 """ let rc01 = """ 00000000000000000000000000000000000000000000000000000000000 01111111111111111100000000000000000001111111111111000000000 01111111111111111110000000000000001111111111111111000000000 01111111111111111111000000000000111111111111111111000000000 01111111100000111111100000000001111111111111111111000000000 00011111100000111111100000000011111110000000111111000000000 00011111100000111111100000000111111100000000000000000000000 00011111111111111111000000000111111100000000000000000000000 00011111111111111110000000000111111100000000000000000000000 00011111111111111111000000000111111100000000000000000000000 00011111100000111111100000000111111100000000000000000000000 00011111100000111111100000000111111100000000000000000000000 00011111100000111111100000000011111110000000111111000000000 01111111100000111111100000000001111111111111111111000000000 01111111100000111111101111110000111111111111111111011111100 01111111100000111111101111110000001111111111111111011111100 01111111100000111111101111110000000001111111111111011111100 00000000000000000000000000000000000000000000000000000000000 """ // Zhang-Suen thinning algorithm in Swift /// function to thin the image func zhangSuen(image: inout [[Int]]) -> [[Int]] { // array of x, y position where need to changed to be white var changing1, changing2: [(Int, Int)] repeat { // set to empty array changing1 = [] changing2 = [] // Step 1 // loop through row of image for y in 1..<image.count-1 { // loop through column of image for x in 1..<image[0].count-1 { // get neighbours of P1 var nb = neighbours(x: x, y: y, image: image) // set P2, P4, P6, P8 from neighbours let P2 = nb[0], P4 = nb[2], P6 = nb[4], P8 = nb[6] // reference: https://www.hackingwithswift.com/example-code/language/how-to-sum-an-array-of-numbers-using-reduce // reference: https://www.hackingwithswift.com/articles/90/how-to-check-whether-a-value-is-inside-a-range if (image[y][x] == 1 && // Condision 0 (2...6).contains(nb.reduce(0, +)) && // Condision 1 transitions(neighbours: &nb) == 1 && // Condision 2 P2 P4 * P6 == 0 && // Condision 3 P4 * P6 * P8 == 0 // Condision 4 ) { // add to step1 changing1 list changing1.append((x,y)) } } } // loop through step1 changing1 list and change to white for (x, y) in changing1 { image[y][x] = 0 } // Step 2 // loop through row of image for y in 1..<image.count-1 { // loop through column of image for x in 1..<image[0].count-1 { // get neighbours of P1 var nb = neighbours(x: x, y: y, image: image) // set P2, P4, P6, P8 from neighbours let P2 = nb[0], P4 = nb[2], P6 = nb[4], P8 = nb[6] if (image[y][x] == 1 && // Condision 0 (2...6).contains(nb.reduce(0, +)) && // Condision 1 transitions(neighbours: &nb) == 1 && // Condision 2 P2 * P4 * P8 == 0 && // Condision 3 P2 * P6 * P8 == 0 // Condision 4 ) { // add to step2 changing2 list changing2.append((x,y)) } } } // loop through step2 changing2 list and change to white for (x, y) in changing2 { image[y][x] = 0 } // finish loop when there's no more place to change to white, when changing1, changing2 are empty } while !changing1.isEmpty && !changing2.isEmpty // return updated image return image } /// function to convert multiline string of 1/0 into 2D Int array func intarray(binstring: String) -> [[Int]] { // reference: https://stackoverflow.com/questions/28611336/how-to-convert-a-string-numeric-in-a-int-array-in-swift // map through each char of input String to convert to Int return binstring.split(separator: "\n").map {$0.compactMap{$0.wholeNumberValue}} } /// function to convert 2D Int array of 1/0 into multiline String of ‘#’ and ‘.’ func toTxt(intmatrix: [[Int]]) -> String { // map through each array of parent array and // map through element of child array and convert to '#' when 1 and to '.' when 0 return intmatrix.map {$0.map { $0 == 1 ? "#" : "."}.joined(separator: "")}.joined(separator: "\n") } /// function to get neighbours of P1 = [P2,P3,P4,P5,P6,P7,P8,P9] func neighbours(x: Int, y: Int, image: [[Int]]) -> [Int] { let i = image // set x, y positions of P1 neighbours let x1 = x+1, y1 = y-1, x_1 = x-1, y_1 = y+1 // return neighbours of P1 return [i[y1][x], i[y1][x1], i[y][x1], i[y_1][x1], // P2,P3,P4,P5 i[y_1][x], i[y_1][x_1], i[y][x_1], i[y1][x_1]] // P6,P7,P8,P9 } /// function to get the number of transitions from white to black, (0 -> 1) in the sequence P2,P3,P4,P5,P6,P7,P8,P9,P2. func transitions(neighbours: inout [Int]) -> Int { // add P2 at the end of neighbours array let n = neighbours + [neighbours[0]] var result = 0 // reference: https://www.marcosantadev.com/arrayslice-in-swift/ // compare between each element of neightbour and next element of the element to check if the transition is 0 -> 1 for (n1, n2) in zip(n, n.suffix(n.count - 1)) { // if the pattern matches, increament result to 1 if (n1, n2) == (0, 1) { result += 1 } } // return number of transitions from 0 to 1 return result } // run testing // array of test examples let testCases: [String] = [beforeTxt, smallrc01, rc01] for picture in testCases { // convert string to 2D Int array var image = intarray(binstring: picture) // print the result print("\nFrom:\n\(toTxt(intmatrix: image))") // run through Zhang-Suen thinning algorithm let after = zhangSuen(image: &image) // print the result print("\nTo thinned:\n\(toTxt(intmatrix: after))") }</syntaxhighlight> {{out}} <pre> From: ##..### ##..### ##..### ##..### ##..##. ##..##. ##..##. ##..##. ##..##. ##..##. ##..##. ##..##. ######. ....... To thinned: ##..### #.....# #.....# #...### #...#.. #...#.. #...#.. #...#.. #...#.. #...#.. #...#.. #...#.. #####.. ....... From: ................................ .#########.......########....... .###...####.....####..####...... .###....###.....###....###...... .###...####.....###............. .#########......###............. .###.####.......###....###...... .###..####..###.####..####.###.. .###...####.###..########..###.. ................................ To thinned: ................................ ..#######.........######........ ..#.....#........##............. ..#......#.......#.............. ..#.....#........#.............. ..#####.#........#.............. .......##........#.............. ........#....#...##....##...#... .........#.........####......... ................................ From: ........................................................... .#################...................#############......... .##################...............################......... .###################............##################......... .########.....#######..........###################......... ...######.....#######.........#######.......######......... ...######.....#######........#######....................... ...#################.........#######....................... ...################..........#######....................... ...#################.........#######....................... ...######.....#######........#######....................... ...######.....#######........#######....................... ...######.....#######.........#######.......######......... .########.....#######..........###################......... .########.....#######.######....##################.######.. .########.....#######.######......################.######.. .########.....#######.######.........#############.######.. ........................................................... To thinned: ........................................................... ........................................................... ....#.##########.......................#######............. .....##........#...................####.......#............ .....#..........#.................##....................... .....#..........#................#......................... .....#..........#................#......................... .....#..........#................#......................... .....############...............#.......................... .....#..........#...............#.......................... .....#..........#................#......................... .....#..........#................#......................... .....#..........#................#......................... .....#............................##....................... .....#.............................############............ .......................###..........................###.... ........................................................... ........................................................... </pre> =={{header\|Tcl}}== Only the single image is converted. <~~lang~~syntaxhighlight lang="tcl"># -- coding: utf-8 -- set data { Line 4,371 ⟶ 5,034: return $data } puts [string map {1 @ 0 .} [join [zhang-suen $data] \n]]</~~lang~~syntaxhighlight> {{out}} Line 4,386 ⟶ 5,049: ................................ </pre> ~~=={{header\|VBA}}==~~ ~~{{trans\|Phix}}~~ ~~<lang vb>Public n As Variant~~ ~~Private Sub init()~~ ~~n = [{-1,0;-1,1;0,1;1,1;1,0;1,-1;0,-1;-1,-1;-1,0}]~~ ~~End Sub~~ ~~Private Function AB(text As Variant, y As Integer, x As Integer, step As Integer) As Variant~~ ~~Dim wtb As Integer~~ ~~Dim bn As Integer~~ ~~Dim prev As String: prev = "#"~~ ~~Dim next_ As String~~ ~~Dim p2468 As String~~ ~~For i = 1 To UBound(n)~~ ~~next_ = Mid(text(y + n(i, 1)), x + n(i, 2), 1)~~ ~~wtb = wtb - (prev = "." And next_ <= "#")~~ ~~bn = bn - (i > 1 And next_ <= "#")~~ ~~If (i And 1) = 0 Then p2468 = p2468 & prev~~ ~~prev = next_~~ ~~Next i~~ ~~If step = 2 Then '-- make it p6842~~ ~~p2468 = Mid(p2468, 3, 2) & Mid(p2468, 1, 2)~~ ~~'p2468 = p2468(3..4)&p2468(1..2)~~ ~~End If~~ ~~Dim ret(2) As Variant~~ ~~ret(0) = wtb~~ ~~ret(1) = bn~~ ~~ret(2) = p2468~~ ~~AB = ret~~ ~~End Function~~ ~~Private Sub Zhang_Suen(text As Variant)~~ ~~Dim wtb As Integer~~ ~~Dim bn As Integer~~ ~~Dim changed As Boolean, changes As Boolean~~ ~~Dim p2468 As String '-- (p6842 for step 2)~~ ~~Dim x As Integer, y As Integer, step As Integer~~ ~~Do While True~~ ~~changed = False~~ ~~For step = 1 To 2~~ ~~changes = False~~ ~~For y = 1 To UBound(text) - 1~~ ~~For x = 2 To Len(text(y)) - 1~~ ~~If Mid(text(y), x, 1) = "#" Then~~ ~~ret = AB(text, y, x, step)~~ ~~wtb = ret(0)~~ ~~bn = ret(1)~~ ~~p2468 = ret(2)~~ ~~If wtb = 1 _~~ ~~And bn >= 2 And bn <= 6 _~~ ~~And InStr(1, Mid(p2468, 1, 3), ".") _~~ ~~And InStr(1, Mid(p2468, 2, 3), ".") Then~~ ~~changes = True~~ ~~text(y) = Left(text(y), x - 1) & "!" & Right(text(y), Len(text(y)) - x)~~ ~~End If~~ ~~End If~~ ~~Next x~~ ~~Next y~~ ~~If changes Then~~ ~~For y = 1 To UBound(text) - 1~~ ~~text(y) = Replace(text(y), "!", ".")~~ ~~Next y~~ ~~changed = True~~ ~~End If~~ ~~Next step~~ ~~If Not changed Then Exit Do~~ ~~Loop~~ ~~Debug.Print Join(text, vbCrLf)~~ ~~End Sub~~ ~~Public Sub main()~~ ~~init~~ ~~Dim Small_rc(9) As String~~ ~~Small_rc(0) = "................................"~~ ~~Small_rc(1) = ".#########.......########......."~~ ~~Small_rc(2) = ".###...####.....####..####......"~~ ~~Small_rc(3) = ".###....###.....###....###......"~~ ~~Small_rc(4) = ".###...####.....###............."~~ ~~Small_rc(5) = ".#########......###............."~~ ~~Small_rc(6) = ".###.####.......###....###......"~~ ~~Small_rc(7) = ".###..####..###.####..####.###.."~~ ~~Small_rc(8) = ".###...####.###..########..###.."~~ ~~Small_rc(9) = "................................"~~ ~~Zhang_Suen (Small_rc)~~ ~~End Sub</lang>{{out}}~~ ~~<pre>................................~~ ~~...######.........######........~~ ~~...#....#.........#....##.......~~ ~~...#....#.........#......#......~~ ~~...#....#.........#.............~~ ~~...####.#.........#.............~~ ~~.......##.........#.............~~ ~~........#....#....#....##...#...~~ ~~.........#....#....####......#..~~ ~~................................</pre>~~ =={{header\|Wren}}== {{trans\|Kotlin}} <~~lang~~syntaxhighlight ~~ecmascript~~lang="wren">class Point { construct new(x, y) { _x = x Line 4,592 ⟶ 5,159: } thinImage.call()</~~lang~~syntaxhighlight> {{out}}