You are right.After ask our developer and test for confirmation ,I found we have already has this function.
If you choose "sliced" when you publish,it will spin before loading all the color and full image. This function is for customer using large image.so viewer can know the blur or gray of the image.
If you do not choose "sliced" when you publish, it will load all the image then begin to spin .
So this feature is already there.
It is a little different in tourweaver6 and tourweaver7 ,but it is same when you choose "sliced".
Thanks Madmux.I should learn more about Tourweaver.
You can try it now Mr prb16.
Tourweaver7 is added more useful features for you.
Welcome to try it and any suggestions are appreciated!