ResearchIndex Home Wechsler, H. Computational Vision . Moments Integrals can also be used to compute geometrical moments of the image.
Projective transformations preserve neither lengths, nor ratios of lengths.
Such a ratio is known as a cross ratio. Since projective transformations are many to one, matching cross ratios are a necessary, but not sufficient, condition for feature matching. In both the Laplacian and Gaussian pyramids, the lowest level of the pyramid is constructed from the original image. Academic Press, 1990. Moments Integrals can also be used to compute geometrical moments of the image.