Impala Documentation

void Impala::Core::Array::relabel	(	VectorDouble &	clusterMap,
		int	width,
		int	height,
		pixgroup *	rg,
		int &	nrClusters,
		int	numpixrm,
		long	sizethreshold
	)

Definition at line 483 of file ColorSegmentation.h.

References Impala::Core::Array::pixgroup::idx, Impala::Core::Array::pixgroup::nrPixInGroup, and UNLABELED.

Referenced by ColorSegmentation().

00485 {
00486     long imsize = width*height;
00487     int x,y;
00488     long i;
00489     int d[4] = {1, -width, -1, width}; 
00490 
00491     //remove pixels at the boundary of a region (thickness = 2*numpixrm)
00492     for (int l=numpixrm; l>0; l--)
00493     {
00494         // make a copy of the clusterMap, to keep the state a pixel is in.
00495         VectorDouble pixstate(clusterMap) ;
00496 
00497         // start after the borderline (first line of pixels)
00498         i = width ;
00499         for (y=1; y<height-1; y++)  {
00500             // skip left-border pixel
00501             i++;
00502             for (x=1; x<width-1; x++) {
00503                 if (clusterMap[i]!=UNLABELED) {
00504 
00505                     bool boundary = false;
00506                     for (int u=0; u<4; u++) {
00507                             // if right,top,left or bottom pixel is from another
00508                             // region, or unlabelled
00509                         if (clusterMap[i+d[u]]!=clusterMap[i])  {
00510                         boundary = true; break;
00511                         }
00512                     }
00513                     if (boundary) pixstate[i] = UNLABELED; //remove from region
00514                 }
00515                 i++;
00516             } // end for(x)
00517 
00518             // skip right-border pixel
00519             i++;
00520         } // end for(y)
00521 
00522             // set the result to clusterMap 
00523         clusterMap = pixstate; 
00524     }
00525 
00526     // renumber the leftover regions
00527     for (i=0; i<nrClusters; i++) rg[i].nrPixInGroup = 0;
00528     for (i=0; i<imsize; i++) 
00529         if (clusterMap[i] != UNLABELED) {
00530             int lb = clusterMap[i];
00531             rg[lb].idx[rg[lb].nrPixInGroup] = i;
00532             rg[lb].nrPixInGroup++;
00533         }
00534 
00535     // UNLABEL the regions that are too small 
00536     int count = 0;
00537     for (int c=0; c<nrClusters; c++) {
00538         if (rg[c].nrPixInGroup >= sizethreshold) {
00539             for (i=0; i<rg[c].nrPixInGroup; i++) clusterMap[rg[c].idx[i]] = count;
00540             count++;
00541         }
00542         else for (i=0; i<rg[c].nrPixInGroup; i++) clusterMap[rg[c].idx[i]] = UNLABELED;
00543     }
00544 
00545     // store the new number of regions.
00546     nrClusters = count;
00547 }