Scale invariance for zernike moment

I read an article that presents the scale invariance of zernike moments. So the author mention that : "scale invariance can be achieved by scaling the original image such that its zeroth-order geometric moment is set equal to a predetermined value"

what is this pretermined value and how to compute it?

Thanks

[hamed]

please answer to this question this is my problem too

[vishal]

denotes the image pixel count (i.e. count of pixels satisfying f(x, y) = 1, for a binary image encoding context). reference- Fractional central moment method for movement-invariant object classification