No you cannot.
A copy has to be certified / notarized in order to be used in lieu of the original for the purpose of identification.
This is true in other areas as well - for example, in Malaysia, students whose passport is sent for their visa renewal are given certified copies of their passports from the school / university to carry with them in case they are stopped.
The certification (a stamp and signature) make the copy valid for identification - otherwise anyone can photoshop a fake looking passport and use it.
Your copies are going to be useful when trying to obtain replacement documents or visas. You can present your copy to the embassy; which is used mainly to lookup your passport number quickly and to issue you a replacement document.
Then you can take a copy of the visa page to the embassy that issued you a visa, along with the replacement document to have it endorsed such that you are not considered illegal in the area.
I think the only place it may work is at a hotel for verifying your identity; but for official / police business I don't think it will suffice; again, as it is something very easy to fake.