I have an idea, though it might be slightly different, it's a good way of finding dupes and making better use of the search function, and granting easier access to pics.
Tags. We tag images with whatever name that fits. Any member should be able to tag images, so this way, all images are labeled and can easily be searched.
Like if the image is a Rozen Pic w/ Suigintou in it, that's black and white, and a very big pic, it will be tagged, by all members, with whatever tag they see fit.
Example. The tags for that rozen pic I just mentioned would be,
Rozen , Monochrome(black&white) , Suigintou , HighRes.
And we will have a list of what tags are available somewhere on the board, for easy access to pics.
Here's other examples of what I'm trying to say:
The tags for this can be: Suigetsu , Yuki , pajama , wallpaper.
The tags for this one can be Futakoi Alternative , Sara , Souju , guns , maid , gif.
So if we choose the 'guns' tag or type out guns in the search function, ALL images that has a gun in it will pop out.
And since not everyone will be kind enough to type out the tag, hopefully tagging images can be done by single click, just by choosing the tag from a list, or requesting a new tag.
Although, this way, might require a whole lot of work. It's up to anony.
This idea actually comes from this other image board I once saw, that uses this method.