Tomo,
Have you actually tried this circuit? As I see it you have 8 1K resistors all in parallel. That will give you a very low resistance and I would be surprised if it worked at all.
You could replace all the 1Ks with a single resistor.
However the question arises as to what happens to the LDRs that are not selected. These have a logic zero on them so you have all the LDRs (but one) connected in parallel to ground giving you a variable low pull down. This means that the light indecent on an LDR that is not selected will affect the reading of one that is.
I can't see this working at all.