Here is a way of achieving that, all though I admit it's cheating a little.
First change to the directory where you want the copy and then
find /home/user -name *.jpg | xargs tar -c | tar -x
This will create the full directory structure in your current directory.
So if you are copying from user1 home directory into /tmp you will end up with
you could then move the new directory to where you really want it. If you want anything more sophisticated than that you'll need to write a full shell script rather than a one-liner.
It works by finding all the files in the /home/user directory, sending the files full path+filename into the pipe. The xargs means that it will run the command once for every file and then run the tar command, which is then untarred into the current directory. The tar command preserves the full path (but strips the initial / so that it is a relative directory rather than an absolute one).