1. A computer-implemented process for generating a local image descriptor for an image patch, comprising using a computer to perform the following process actions: smoothing values of pixels of the image patch; employing a transformation to produce a transform vector for each of a set of sample points spaced across the image patch, wherein each transform vector produced has a prescribed number of elements k and numerically represents the smoothed values of a pixel or pixels in the vicinity of the sample point associated with the transform vector; employing a spatial pooling technique to spatially accumulate weighted versions of the transform vectors to produce N linearly summed vectors each having k elements, which are concatenated to form a raw local image descriptor having kN elements, wherein each linearly summed vector is computed by summing the transform vectors associated with sample points found within a local pooling region centered on a pooling point which is part of a pattern of pooling points located across the image patch, and wherein each transform vector used to produce a linearly summed vector is weighted prior to the summing using a normalized Gaussian weighting function associated with the local pooling region of the linearly summed vector; and normalizing the raw local image descriptor using a prescribed normalization technique.