Fix issue #623 & doc image reference (ximgproc/slic).

modules/ximgproc/include/opencv2/ximgproc/slic.hpp

@@ -148,7 +148,7 @@ superpixel algorithm, which are: region_size and ruler. It preallocate some buff
 computing iterations over the given image. An example of SLIC versus SLICO is ilustrated in the
 following picture.
 
-![image](pics/slic_slico_kermit.png)
+![image](pics/superpixels_slic.png)
 
  */
 

modules/ximgproc/src/slic.cpp

@@ -226,11 +226,12 @@ void SuperpixelSLICImpl::initialize()
     else
       CV_Error( Error::StsInternal, "No such algorithm" );
 
+    // update amount of labels now
+    m_numlabels = (int)m_kseeds[0].size();
+
     // perturb seeds given edges
     if ( perturbseeds ) PerturbSeeds( edgemag );
 
-    // update amount of labels now
-    m_numlabels = (int)m_kseeds[0].size();
 }
 
 void SuperpixelSLICImpl::iterate( int num_iterations )