Connectivity zone MARK: Implementation of bwlabel in C ++ (based on opencv)

Similar to the C ++ version Implementation of bwlabel in MATLAB to mark connected areas, based on opencv, as follows:

 

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/// Bwlabel. cpp

# Include "CV. H "<br/> # include" highgui. H "<br/> # define no_object 0 <br/> # define min (x, y) (x) <(y ))? (X): (y) <br/> # define ELEM (IMG, R, c) (cv_image_elem (IMG, unsigned char, R, c )) <br/> # define onetwo (L, R, C, col) (L [(r) * (COL) + C]) <br/> int find (INT set [], int X) <br/>{< br/> int r = x; <br/> while (set [R]! = R) <br/> r = set [R]; <br/> return R; <br/>}< br/>/* <br/> labeling scheme <br/> +-+ <br/> | d | c | E | <br/> +-+ <br/> | B | A | <br/> +-+ <br/> | <br/> +-+ <br/> A is the center pixel of a neighborhood. in the 3 versions of <br/> connectedness: <br/> 4: A connects to B and C <br/> 6: A connects to B, C, and D <br/> 8: A connects to B, C, D, and e <br/> */<br/> //////////////////////////// /<br/> // By yysdsyl <br/> // input: IMG -- gray image <br/> // n -- N connectedness <br/> // labels -- label of each pixel, labels [row * Col] <br/> // output: number of connected regions <br/> // Email: yysdsyl@qq.com <br/> int bwlabel (iplimage * IMG, int N, int * labels) <br/> {<br/> If (n! = 4 & n! = 8) <br/> N = 4; <br/> int Nr = IMG-> height; <br/> int NC = IMG-> width; <br/> int Total = nR * NC; <br/> // results <br/> memset (labels, 0, total * sizeof (INT )); <br/> int nobj = 0; // number of objects found in image <br/> // other variables <br/> int * lset = new int [total]; // label table <br/> memset (lset, 0, total * sizeof (INT); <br/> int ntable = 0; <br/> for (INT r = 0; r <NR; r ++) <br/>{< br/> for (I Nt c = 0; C <NC; C ++) <br/>{< br/> If (ELEM (IMG, R, c )) // if A is an object <br/>{< br/> // get the neighboring pixels B, C, D, and E <br/> int B, c, d, E; <br/> If (C = 0) <br/> B = 0; <br/> else <br/> B = find (lset, onetwo (labels, R, C-1, NC); <br/> If (r = 0) <br/> C = 0; <br/> else <br/> C = find (lset, onetwo (labels, R-1, C, NC )); <br/> If (r = 0 | C = 0) <br/> D = 0; <br/> else <br /> D = find (lset, onetwo (labels, R-1, C-1, NC )); <br/> If (r = 0 | C = NC-1) <br/> E = 0; <br/> else <br/> E = find (lset, onetwo (labels, R-1, C + 1, NC )); <br/> If (n = 4) <br/> {<br/> // apply 4 connectedness <br/> If (B & C) <br/> {// B and C are labeled <br/> If (B = C) <br/> onetwo (labels, R, C, NC) = B; <br/> else {<br/> lset [c] = B; <br/> onetwo (labels, R, C, NC) = B; <br/>}< br />}< Br/> else if (B) // B is object but C is not <br/> onetwo (labels, R, C, NC) = B; <br/> else if (c) // C is object but B is not <br/> onetwo (labels, R, C, NC) = C; <br/> else <br/> {// B, c, d Not Object-new object <br/> // label and put into Table <br/> ntable ++; <br/> onetwo (labels, R, C, NC) = lset [ntable] = ntable; <br/>}< br/> else if (n = 6) <br/> {<br/> // apply 6 connected NES S <br/> If (d) // D object, copy label and move on <br/> onetwo (labels, R, C, NC) = D; <br/> else if (B & C) <br/> {// B and C are labeled <br/> If (B = C) <br/> onetwo (labels, R, C, NC) = B; <br/> else <br/>{< br/> int tlabel = min (B, c); <br/> lset [B] = tlabel; <br/> lset [c] = tlabel; <br/> onetwo (labels, R, C, NC) = tlabel; <br/>}< br/> else if (B) // B is object but C is not <br/> onetwo (L Abels, R, C, NC) = B; <br/> else if (c) // C is object but B is not <br/> onetwo (labels, R, c, NC) = C; <br/> else <br/> {// B, c, d Not Object-new object <br/> // label and put into Table <br/> ntable ++; <br/> onetwo (labels, R, C, NC) = lset [ntable] = ntable; <br/>}< br/> else if (n = 8) <br/>{< br/> // apply 8 connectedness <br/> If (B | c | d | E) <br/>{< br/> int tlabel = B; <br/> If (B) <br/> tlabel = B; <br/> else if (c) <br/> tlabel = C; <br/> else if (d) <br/> tlabel = D; <br/> else if (e) <br/> tlabel = E; <br/> onetwo (labels, R, C, NC) = tlabel; <br/> If (B & B! = Tlabel) <br/> lset [B] = tlabel; <br/> If (C & C! = Tlabel) <br/> lset [c] = tlabel; <br/> If (D & D! = Tlabel) <br/> lset [d] = tlabel; <br/> If (E & E! = Tlabel) <br/> lset [e] = tlabel; <br/>}< br/> else <br/> {<br/> // label and put into Table <br/> ntable ++; <br/> onetwo (labels, R, C, NC) = lset [ntable] = ntable; <br/>}< br/> else <br/> {<br/> onetwo (labels, R, C, NC) = no_object; // A is not an object so leave it <br/>}< br/> // specify lidate component table <br/> (int I = 0; I <= ntable; I ++) <br/> lset [I] = find (lset, I ); <br/> // run image through the look-up table <br/> for (INT r = 0; r <NR; r ++) <br/> for (int c = 0; C <NC; C ++) <br/> onetwo (labels, R, C, NC) = lset [onetwo (labels, r, C, NC)]; <br/> // count up the objects in the image <br/> for (INT I = 0; I <= ntable; I ++) <br/> lset [I] = 0; <br/> for (INT r = 0; r <NR; r ++) <br/> for (int c = 0; C <NC; C ++) <br/> lset [onetwo (labels, R, C, NC)] ++; <br/> // number the objects from 1 through n objects <br/> nobj = 0; <br/> lset [0] = 0; <br/> for (INT I = 1; I <= ntable; I ++) <br/> If (lset [I]> 0) <br/> lset [I] = ++ nobj; <br/> // run through the look-up table again <br/> for (INT r = 0; r <NR; r ++) <br/> for (int c = 0; C <NC; C ++) <br/> onetwo (labels, R, C, NC) = lset [onetwo (labels, R, C, NC)]; <br/> // <br/> Delete [] lset; <br/> return nobj; <br/>}< br/>

 

CodeDownload: bwlabel. cpp