//M*/
//
#include "precomp.hpp"
+#include <vector>
namespace cv{
namespace connectedcomponents{
- using std::vector;
+
+ template<typename LabelT>
+ struct NoOp{
+ NoOp(){
+ }
+ void init(const LabelT labels){
+ (void) labels;
+ }
+ inline
+ void operator()(int r, int c, LabelT l){
+ (void) r;
+ (void) c;
+ (void) l;
+ }
+ void finish(){}
+ };
+ template<typename LabelT>
+ struct CCStatsOp{
+ std::vector<cv::ConnectedComponentStats> &statsv;
+ CCStatsOp(std::vector<cv::ConnectedComponentStats> &_statsv): statsv(_statsv){
+ }
+ inline
+ void init(const LabelT nlabels){
+ statsv.clear();
+ cv::ConnectedComponentStats stats = cv::ConnectedComponentStats();
+ stats.lower_x = std::numeric_limits<LabelT>::max();
+ stats.lower_y = std::numeric_limits<LabelT>::max();
+ stats.upper_x = std::numeric_limits<LabelT>::min();
+ stats.upper_y = std::numeric_limits<LabelT>::min();
+ stats.centroid_x = 0;
+ stats.centroid_y = 0;
+ stats.integral_x = 0;
+ stats.integral_y = 0;
+ stats.area = 0;
+ statsv.resize(nlabels, stats);
+ }
+ void operator()(int r, int c, LabelT l){
+ ConnectedComponentStats &stats = statsv[l];
+ if(c > stats.upper_x){
+ stats.upper_x = c;
+ }else{
+ if(c < stats.lower_x){
+ stats.lower_x = c;
+ }
+ }
+ if(r > stats.upper_y){
+ stats.upper_y = r;
+ }else{
+ if(r < stats.lower_y){
+ stats.lower_y = r;
+ }
+ }
+ stats.integral_x += c;
+ stats.integral_y += r;
+ stats.area++;
+ }
+ void finish(){
+ for(size_t l = 0; l < statsv.size(); ++l){
+ ConnectedComponentStats &stats = statsv[l];
+ stats.lower_x = std::min(stats.lower_x, stats.upper_x);
+ stats.lower_y = std::min(stats.lower_y, stats.upper_y);
+ stats.centroid_x = stats.integral_x / double(stats.area);
+ stats.centroid_y = stats.integral_y / double(stats.area);
+ }
+ }
+ };
//Find the root of the tree of node i
template<typename LabelT>
inline static
- LabelT findRoot(const vector<LabelT> &P, LabelT i){
+ LabelT findRoot(const LabelT *P, LabelT i){
LabelT root = i;
while(P[root] < root){
root = P[root];
//Make all nodes in the path of node i point to root
template<typename LabelT>
inline static
- void setRoot(vector<LabelT> &P, LabelT i, LabelT root){
+ void setRoot(LabelT *P, LabelT i, LabelT root){
while(P[i] < i){
LabelT j = P[i];
P[i] = root;
//Find the root of the tree of the node i and compress the path in the process
template<typename LabelT>
inline static
- LabelT find(vector<LabelT> &P, LabelT i){
+ LabelT find(LabelT *P, LabelT i){
LabelT root = findRoot(P, i);
setRoot(P, i, root);
return root;
//unite the two trees containing nodes i and j and return the new root
template<typename LabelT>
inline static
- LabelT set_union(vector<LabelT> &P, LabelT i, LabelT j){
+ LabelT set_union(LabelT *P, LabelT i, LabelT j){
LabelT root = findRoot(P, i);
if(i != j){
LabelT rootj = findRoot(P, j);
//Flatten the Union Find tree and relabel the components
template<typename LabelT>
inline static
- LabelT flattenL(vector<LabelT> &P){
+ LabelT flattenL(LabelT *P, LabelT length){
LabelT k = 1;
- for(size_t i = 1; i < P.size(); ++i){
+ for(LabelT i = 1; i < length; ++i){
if(P[i] < i){
P[i] = P[P[i]];
}else{
return k;
}
- ////Flatten the Union Find tree - inconsistent labels
- //void flatten(int P[], int size){
- // for(int i = 1; i < size; ++i){
- // P[i] = P[P[i]];
- // }
- //}
- const int G4[2][2] = {{-1, 0}, {0, -1}};//b, d neighborhoods
- const int G8[4][2] = {{-1, -1}, {-1, 0}, {-1, 1}, {0, -1}};//a, b, c, d neighborhoods
//Based on "Two Strategies to Speed up Connected Components Algorithms", the SAUF (Scan array union find) variant
//using decision trees
//Kesheng Wu, et al
- template<typename LabelT, typename PixelT, int connectivity = 8>
+ //Note: rows are encoded as position in the "rows" array to save lookup times
+ //reference for 4-way: {{-1, 0}, {0, -1}};//b, d neighborhoods
+ const int G4[2][2] = {{1, 0}, {0, -1}};//b, d neighborhoods
+ //reference for 8-way: {{-1, -1}, {-1, 0}, {-1, 1}, {0, -1}};//a, b, c, d neighborhoods
+ const int G8[4][2] = {{1, -1}, {1, 0}, {1, 1}, {0, -1}};//a, b, c, d neighborhoods
+ template<typename LabelT, typename PixelT, typename StatsOp = NoOp<LabelT>, int connectivity = 8>
struct LabelingImpl{
- LabelT operator()(Mat &L, const Mat &I){
+ LabelT operator()(Mat &L, const Mat &I, StatsOp &sop){
const int rows = L.rows;
const int cols = L.cols;
- size_t nPixels = size_t(rows) * cols;
- vector<LabelT> P; P.push_back(0);
- LabelT l = 1;
+ size_t Plength = (size_t(rows + 3 - 1)/3) * (size_t(cols + 3 - 1)/3);
+ if(connectivity == 4){
+ Plength = 4 * Plength;//a quick and dirty upper bound, an exact answer exists if you want to find it
+ //the 4 comes from the fact that a 3x3 block can never have more than 4 unique labels
+ }
+ LabelT *P = (LabelT *) fastMalloc(sizeof(LabelT) * Plength);
+ P[0] = 0;
+ LabelT lunique = 1;
//scanning phase
for(int r_i = 0; r_i < rows; ++r_i){
- for(int c_i = 0; c_i < cols; ++c_i){
- if(!I.at<PixelT>(r_i, c_i)){
- L.at<LabelT>(r_i, c_i) = 0;
- continue;
- }
- if(connectivity == 8){
- const int a = 0;
- const int b = 1;
- const int c = 2;
- const int d = 3;
-
- bool T[4];
-
- for(size_t i = 0; i < 4; ++i){
- int gr = r_i + G8[i][0];
- int gc = c_i + G8[i][1];
- T[i] = false;
- if(gr >= 0 && gr < rows && gc >= 0 && gc < cols){
- if(I.at<PixelT>(gr, gc)){
- T[i] = true;
- }
- }
+ LabelT *Lrow = (LabelT *)(L.data + L.step.p[0] * r_i);
+ LabelT *Lrow_prev = (LabelT *)(((char *)Lrow) - L.step.p[0]);
+ const PixelT *Irow = (PixelT *)(I.data + I.step.p[0] * r_i);
+ const PixelT *Irow_prev = (const PixelT *)(((char *)Irow) - I.step.p[0]);
+ LabelT *Lrows[2] = {
+ Lrow,
+ Lrow_prev
+ };
+ const PixelT *Irows[2] = {
+ Irow,
+ Irow_prev
+ };
+ if(connectivity == 8){
+ const int a = 0;
+ const int b = 1;
+ const int c = 2;
+ const int d = 3;
+ const bool T_a_r = (r_i - G8[a][0]) >= 0;
+ const bool T_b_r = (r_i - G8[b][0]) >= 0;
+ const bool T_c_r = (r_i - G8[c][0]) >= 0;
+ for(int c_i = 0; Irows[0] != Irow + cols; ++Irows[0], c_i++){
+ if(!*Irows[0]){
+ Lrow[c_i] = 0;
+ continue;
}
+ Irows[1] = Irow_prev + c_i;
+ Lrows[0] = Lrow + c_i;
+ Lrows[1] = Lrow_prev + c_i;
+ const bool T_a = T_a_r && (c_i + G8[a][1]) >= 0 && *(Irows[G8[a][0]] + G8[a][1]);
+ const bool T_b = T_b_r && *(Irows[G8[b][0]] + G8[b][1]);
+ const bool T_c = T_c_r && (c_i + G8[c][1]) < cols && *(Irows[G8[c][0]] + G8[c][1]);
+ const bool T_d = (c_i + G8[d][1]) >= 0 && *(Irows[G8[d][0]] + G8[d][1]);
//decision tree
- if(T[b]){
+ if(T_b){
//copy(b)
- L.at<LabelT>(r_i, c_i) = L.at<LabelT>(r_i + G8[b][0], c_i + G8[b][1]);
+ *Lrows[0] = *(Lrows[G8[b][0]] + G8[b][1]);
}else{//not b
- if(T[c]){
- if(T[a]){
+ if(T_c){
+ if(T_a){
//copy(c, a)
- L.at<LabelT>(r_i, c_i) = set_union(P, L.at<LabelT>(r_i + G8[c][0], c_i + G8[c][1]), L.at<LabelT>(r_i + G8[a][0], c_i + G8[a][1]));
+ *Lrows[0] = set_union(P, *(Lrows[G8[c][0]] + G8[c][1]), *(Lrows[G8[a][0]] + G8[a][1]));
}else{
- if(T[d]){
+ if(T_d){
//copy(c, d)
- L.at<LabelT>(r_i, c_i) = set_union(P, L.at<LabelT>(r_i + G8[c][0], c_i + G8[c][1]), L.at<LabelT>(r_i + G8[d][0], c_i + G8[d][1]));
+ *Lrows[0] = set_union(P, *(Lrows[G8[c][0]] + G8[c][1]), *(Lrows[G8[d][0]] + G8[d][1]));
}else{
//copy(c)
- L.at<LabelT>(r_i, c_i) = L.at<LabelT>(r_i + G8[c][0], c_i + G8[c][1]);
+ *Lrows[0] = *(Lrows[G8[c][0]] + G8[c][1]);
}
}
}else{//not c
- if(T[a]){
+ if(T_a){
//copy(a)
- L.at<LabelT>(r_i, c_i) = L.at<LabelT>(r_i + G8[a][0], c_i + G8[a][1]);
+ *Lrows[0] = *(Lrows[G8[a][0]] + G8[a][1]);
}else{
- if(T[d]){
+ if(T_d){
//copy(d)
- L.at<LabelT>(r_i, c_i) = L.at<LabelT>(r_i + G8[d][0], c_i + G8[d][1]);
+ *Lrows[0] = *(Lrows[G8[d][0]] + G8[d][1]);
}else{
//new label
- L.at<LabelT>(r_i, c_i) = l;
- P.push_back(l);//P[l] = l;
- l = l + 1;
+ *Lrows[0] = lunique;
+ P[lunique] = lunique;
+ lunique = lunique + 1;
}
}
}
}
- }else{
- //B & D only
- const int b = 0;
- const int d = 1;
- assert(connectivity == 4);
- bool T[2];
- for(size_t i = 0; i < 2; ++i){
- int gr = r_i + G4[i][0];
- int gc = c_i + G4[i][1];
- T[i] = false;
- if(gr >= 0 && gr < rows && gc >= 0 && gc < cols){
- if(I.at<PixelT>(gr, gc)){
- T[i] = true;
- }
- }
+ }
+ }else{
+ //B & D only
+ assert(connectivity == 4);
+ const int b = 0;
+ const int d = 1;
+ const bool T_b_r = (r_i - G4[b][0]) >= 0;
+ for(int c_i = 0; Irows[0] != Irow + cols; ++Irows[0], c_i++){
+ if(!*Irows[0]){
+ Lrow[c_i] = 0;
+ continue;
}
-
- if(T[b]){
- if(T[d]){
+ Irows[1] = Irow_prev + c_i;
+ Lrows[0] = Lrow + c_i;
+ Lrows[1] = Lrow_prev + c_i;
+ const bool T_b = T_b_r && *(Irows[G4[b][0]] + G4[b][1]);
+ const bool T_d = (c_i + G4[d][1]) >= 0 && *(Irows[G4[d][0]] + G4[d][1]);
+ if(T_b){
+ if(T_d){
//copy(d, b)
- L.at<LabelT>(r_i, c_i) = set_union(P, L.at<LabelT>(r_i + G4[d][0], c_i + G4[d][1]), L.at<LabelT>(r_i + G4[b][0], c_i + G4[b][1]));
+ *Lrows[0] = set_union(P, *(Lrows[G4[d][0]] + G4[d][1]), *(Lrows[G4[b][0]] + G4[b][1]));
}else{
//copy(b)
- L.at<LabelT>(r_i, c_i) = L.at<LabelT>(r_i + G4[b][0], c_i + G4[b][1]);
+ *Lrows[0] = *(Lrows[G4[b][0]] + G4[b][1]);
}
}else{
- if(T[d]){
+ if(T_d){
//copy(d)
- L.at<LabelT>(r_i, c_i) = L.at<LabelT>(r_i + G4[d][0], c_i + G4[d][1]);
+ *Lrows[0] = *(Lrows[G4[d][0]] + G4[d][1]);
}else{
//new label
- L.at<LabelT>(r_i, c_i) = l;
- P.push_back(l);//P[l] = l;
- l = l + 1;
+ *Lrows[0] = lunique;
+ P[lunique] = lunique;
+ lunique = lunique + 1;
}
}
-
}
}
}
//analysis
- LabelT nLabels = flattenL(P);
+ LabelT nLabels = flattenL(P, lunique);
+ sop.init(nLabels);
- //assign final labels
- for(size_t r = 0; r < rows; ++r){
- for(size_t c = 0; c < cols; ++c){
- L.at<LabelT>(r, c) = P[L.at<LabelT>(r, c)];
+ for(int r_i = 0; r_i < rows; ++r_i){
+ LabelT *Lrow_start = (LabelT *)(L.data + L.step.p[0] * r_i);
+ LabelT *Lrow_end = Lrow_start + cols;
+ LabelT *Lrow = Lrow_start;
+ for(int c_i = 0; Lrow != Lrow_end; ++Lrow, ++c_i){
+ const LabelT l = P[*Lrow];
+ *Lrow = l;
+ sop(r_i, c_i, l);
}
}
+ sop.finish();
+ fastFree(P);
+
return nLabels;
}//End function LabelingImpl operator()
}//end namespace connectedcomponents
//L's type must have an appropriate depth for the number of pixels in I
-uint64_t connectedComponents(Mat &L, const Mat &I, int connectivity){
+template<typename StatsOp>
+uint64_t connectedComponents_sub1(Mat &L, const Mat &I, int connectivity, StatsOp &sop){
CV_Assert(L.rows == I.rows);
CV_Assert(L.cols == I.cols);
CV_Assert(L.channels() == 1 && I.channels() == 1);
if(lDepth == CV_8U){
if(iDepth == CV_8U || iDepth == CV_8S){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<uint8_t, uint8_t, 4>()(L, I);
+ return (uint64_t) LabelingImpl<uint8_t, uint8_t, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<uint8_t, uint8_t, 8>()(L, I);
+ return (uint64_t) LabelingImpl<uint8_t, uint8_t, StatsOp, 8>()(L, I, sop);
}
}else if(iDepth == CV_16U || iDepth == CV_16S){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<uint8_t, uint16_t, 4>()(L, I);
+ return (uint64_t) LabelingImpl<uint8_t, uint16_t, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<uint8_t, uint16_t, 8>()(L, I);
+ return (uint64_t) LabelingImpl<uint8_t, uint16_t, StatsOp, 8>()(L, I, sop);
}
}else if(iDepth == CV_32S){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<uint8_t, int32_t, 4>()(L, I);
+ return (uint64_t) LabelingImpl<uint8_t, int32_t, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<uint8_t, int32_t, 8>()(L, I);
+ return (uint64_t) LabelingImpl<uint8_t, int32_t, StatsOp, 8>()(L, I, sop);
}
}else if(iDepth == CV_32F){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<uint8_t, float, 4>()(L, I);
+ return (uint64_t) LabelingImpl<uint8_t, float, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<uint8_t, float, 8>()(L, I);
+ return (uint64_t) LabelingImpl<uint8_t, float, StatsOp, 8>()(L, I, sop);
}
}else if(iDepth == CV_64F){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<uint8_t, double, 4>()(L, I);
+ return (uint64_t) LabelingImpl<uint8_t, double, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<uint8_t, double, 8>()(L, I);
+ return (uint64_t) LabelingImpl<uint8_t, double, StatsOp, 8>()(L, I, sop);
}
}
}else if(lDepth == CV_16U){
if(iDepth == CV_8U || iDepth == CV_8S){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<uint16_t, uint8_t, 4>()(L, I);
+ return (uint64_t) LabelingImpl<uint16_t, uint8_t, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<uint16_t, uint8_t, 8>()(L, I);
+ return (uint64_t) LabelingImpl<uint16_t, uint8_t, StatsOp, 8>()(L, I, sop);
}
}else if(iDepth == CV_16U || iDepth == CV_16S){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<uint16_t, uint16_t, 4>()(L, I);
+ return (uint64_t) LabelingImpl<uint16_t, uint16_t, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<uint16_t, uint16_t, 8>()(L, I);
+ return (uint64_t) LabelingImpl<uint16_t, uint16_t, StatsOp, 8>()(L, I, sop);
}
}else if(iDepth == CV_32S){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<uint16_t, int32_t, 4>()(L, I);
+ return (uint64_t) LabelingImpl<uint16_t, int32_t, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<uint16_t, int32_t, 8>()(L, I);
+ return (uint64_t) LabelingImpl<uint16_t, int32_t, StatsOp, 8>()(L, I, sop);
}
}else if(iDepth == CV_32F){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<uint16_t, float, 4>()(L, I);
+ return (uint64_t) LabelingImpl<uint16_t, float, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<uint16_t, float, 8>()(L, I);
+ return (uint64_t) LabelingImpl<uint16_t, float, StatsOp, 8>()(L, I, sop);
}
}else if(iDepth == CV_64F){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<uint16_t, double, 4>()(L, I);
+ return (uint64_t) LabelingImpl<uint16_t, double, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<uint16_t, double, 8>()(L, I);
+ return (uint64_t) LabelingImpl<uint16_t, double, StatsOp, 8>()(L, I, sop);
}
}
}else if(lDepth == CV_32S){
+ //note that signed types don't really make sense here and not being able to use uint32_t matters for scientific projects
+ //OpenCV: how should we proceed? .at<T> typechecks in debug mode
if(iDepth == CV_8U || iDepth == CV_8S){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<int32_t, uint8_t, 4>()(L, I);
+ return (uint64_t) LabelingImpl<int32_t, uint8_t, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<int32_t, uint8_t, 8>()(L, I);
+ return (uint64_t) LabelingImpl<int32_t, uint8_t, StatsOp, 8>()(L, I, sop);
}
}else if(iDepth == CV_16U || iDepth == CV_16S){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<int32_t, uint16_t, 4>()(L, I);
+ return (uint64_t) LabelingImpl<int32_t, uint16_t, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<int32_t, uint16_t, 8>()(L, I);
+ return (uint64_t) LabelingImpl<int32_t, uint16_t, StatsOp, 8>()(L, I, sop);
}
}else if(iDepth == CV_32S){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<int32_t, int32_t, 4>()(L, I);
+ return (uint64_t) LabelingImpl<int32_t, int32_t, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<int32_t, int32_t, 8>()(L, I);
+ return (uint64_t) LabelingImpl<int32_t, int32_t, StatsOp, 8>()(L, I, sop);
}
}else if(iDepth == CV_32F){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<int32_t, float, 4>()(L, I);
+ return (uint64_t) LabelingImpl<int32_t, float, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<int32_t, float, 8>()(L, I);
+ return (uint64_t) LabelingImpl<int32_t, float, StatsOp, 8>()(L, I, sop);
}
}else if(iDepth == CV_64F){
if(connectivity == 4){
- return (uint64_t) LabelingImpl<int32_t, double, 4>()(L, I);
+ return (uint64_t) LabelingImpl<int32_t, double, StatsOp, 4>()(L, I, sop);
}else{
- return (uint64_t) LabelingImpl<int32_t, double, 8>()(L, I);
+ return (uint64_t) LabelingImpl<int32_t, double, StatsOp, 8>()(L, I, sop);
}
+ }else{
+ CV_Assert(false);
}
}
return -1;
}
+uint64_t connectedComponents(Mat &L, const Mat &I, int connectivity){
+ int lDepth = L.depth();
+ if(lDepth == CV_8U){
+ connectedcomponents::NoOp<uint8_t> sop; return connectedComponents_sub1(L, I, connectivity, sop);
+ }else if(lDepth == CV_16U){
+ connectedcomponents::NoOp<uint16_t> sop; return connectedComponents_sub1(L, I, connectivity, sop);
+ }else if(lDepth == CV_32S){
+ connectedcomponents::NoOp<uint32_t> sop; return connectedComponents_sub1(L, I, connectivity, sop);
+ }else{
+ CV_Assert(false);
+ return 0;
+ }
+}
+
+uint64_t connectedComponents(Mat &L, const Mat &I, std::vector<ConnectedComponentStats> &statsv, int connectivity){
+ int lDepth = L.depth();
+ if(lDepth == CV_8U){
+ connectedcomponents::CCStatsOp<uint8_t> sop(statsv); return connectedComponents_sub1(L, I, connectivity, sop);
+ }else if(lDepth == CV_16U){
+ connectedcomponents::CCStatsOp<uint16_t> sop(statsv); return connectedComponents_sub1(L, I, connectivity, sop);
+ }else if(lDepth == CV_32S){
+ connectedcomponents::CCStatsOp<uint32_t> sop(statsv); return connectedComponents_sub1(L, I, connectivity, sop);
+ }else{
+ CV_Assert(false);
+ return 0;
+ }
+}
}