Hi Khalid,
From my experience the CenterLineReplacer wont work as expected with complex geometries, this is also stated in the help: 'This transformer works best with long, narrow areas.'
I would try and create smaller narrow areas to get a reasonable center lines that can later be joined.
Itay
You can create lines form the parcels and then explode them to linepieces.
Then calculate the intersections of the lines in incremental steps.(1m, 2m etc.).
This then results in a network of lines.
You can, for instance. overlay this network on the "between parcels" area.
This would result in the areas between parcels, but in smaller (mostly rectangular)sections wich you can use the centerlinereplacer on.
Resulting centerlines can then by joined.