DOC: Add some comments in splitter code

include/lsgrmSplitter.txx

@@ -47,26 +47,20 @@ void SplitOTBImage(TInputImage * imagePtr, // input image
     for(unsigned int col = 0; col < nbTilesX; ++col)
       {
 
-      // Compute current tile start
+      // Compute current tile start and size
       startX = col * tileWidth;
       startY = row * tileHeight;
+      sizeX = tileWidth;
+      sizeY = tileHeight;
 
       // Current tile size might be different for right and bottom borders
       if (col == nbTilesX -1)
         {
-        sizeX = tileWidth + imageWidth % tileWidth;
-        }
-      else
-        {
-        sizeX = tileWidth;
+        sizeX += imageWidth % tileWidth;
         }
       if (row == nbTilesY -1)
         {
-        sizeY = tileHeight + imageHeight % tileHeight;
-        }
-      else
-        {
-        sizeY = tileHeight;
+        sizeY += imageHeight % tileHeight;
         }
 
       /* Margin at the top ? */